Can a bike with an internal bottom bracket be retrofitted to have an external bottom bracket?

The external bottom bracket uses the same thread size and shell width as an older internal BB. They were specifically designed to allow use in a standardized frame without redesign.

They do require a new crank set, and depending on the model, and what is on your current bike, that may mean the purchase of extra components in order to be compatible with the correct number of gears/width of chain. If you are going from 9 speed MTB to 9 speed MTB components, for example, a like for like change, then it should be just the crank set and BB that change.

An external BB is also designed to fit on either a 68mm or 73mm shell. They are universal, as long as you dont have a pressfit BB, or an Italian thread BB. Similar crank sets are available for non-english thread BB's, but it must be designed for your frame's BB shell type specifically.


Can I replace 27.5x2.25 tire with a hybrid/road tire?

Yes, you can replace your 27.5 tires with 650b tires as long as they fit your current rim. You need to get the internal rim width (B on the next picture) and use the following table to see if you can use the tire that you want on that specific rim. As long as the combination of internal width (in mm) and tire section width (in mm as well), then you should be able to use a narrower tire. Keep in mind that the table is fairly conservative, but when it comes to safety, it's always better to do things properly to avoid personal injury.


I believe the eyelets are there to allow water to drain out of the pockets. There's probably no practical need for them unless you ride in torrential rain.

The manufacturer may include them to give an impression that the shorts will make you prepared for all possible conditions, or they may be trying to mimic the style of board shorts (as suggested in a few of the comments).


Confusion regarding the Shimano numering system

Not a full answer, but I can fill in one small blank for you - in the CS-HG30-8I, the HG refers to Hyper Glide - this is Shimano's name for multi-speed sprockets that are designed to allow smooth gear shifting.


Can I mix & match different chainring brand/model?

Should be fine, if the new 32t ring is made to be used in a double or triple crankset then your gold. If it is made to be run independently in a 1x drivetrain (Such as a narrow/wide ring) then it will cause shifting issues.

The larger of the two (or three) rings has shifting ramps and/or pins that help guide the chain up during shifting. If it is made to be used in a multiple ring setup then these should be present, generally they rings will list what type of setup they are intended for as well such as 1x , 2x or 3x.

The other thing to check to to be sure the bolt pattern (BCD) is the same so that they will bolt together. You may also consider getting a new chain at the same time if it has been awhile.


This series should prove informative (I have linked the first of three):
Hal will show you!


How to change chainrings on this Tiagra crankset?

The crankset (110 BCD - Bolt Circle Diameter) is unlikely to accept a 30T chainring. It definitely isn't supported by Shimano. You need a new crank.
Look at subcompact cranksets like, e.g., FSA Tempo Adventure (10/11 speed). Note that this specific one also uses a different bottom bracket.


What kind of bike do I have, "manufacturer/model"

Heat tube badge is "motobecane" which used to be a well-reputed French brand which went bust in the 1980s.    But it says USA which means its from the US company that aquired the trademarks and this is simply a rebadged asian bike frame.  The frame size is labelled as 49cm which is quite small, suiting a shorter-legged adult.

However your example has been seriously modified - for a start its a fixed speed/single speed flipflop hub so someone has removed all the gear system.

Also noted that it has only one brake, and the person building it didn't leave any hood replacements on the bars. Meaning that the Hoods hand position is going to be unusable, possibly why the bars are cocked up at an angle.

Workaround - dummy hoods.  Go read this question for more  How do I use retro drop down handlebars with no hoods?

Consider that 90+% of the braking effect comes from the front brake, riding one back brake is limiting your ability to stop.  And if you're in a singlespeed then you only have one brake, which is not redundant and therefore not legal in many parts of the world.

Also noted it has a suspension seatpost, which sound great but in reality simply interfere with your leg height while riding.

Another option is to try contacting MotobecaneUSA with the serial number and see what they say.  Don't expect a lot.


Are there LED based dynamo powered lights suitable for night time MTB riding on singletrack?

i have been using the Supernova e3 Triple for night-time singletrack missions for the past two winters.....all I can say is awesome, completely awesome. 870 Lumens. bright.

I used a Shimano Alfine dynamo hub and built a complete 'night wheel' with a DT 4.2d rim, it has rubber and a rotor mounted so swap-over time is very quick. We have months of mud, ice and snow here and never once had a problem with the high quality Supernova connectors.

I cannot recomend this set-up enough. with the E3 rear light you are also nice a safe for the Asphalt connectors between the trails.

good luck.


Easy things to check:

Pad not aligned  with the rim properly
Pads too far away from rim, requiring excessive lever travel before engagement
Excessive toe-out

You may also have too much flexibility in your brake cable and housing which limits the amount of braking force at the lever which is translated to the calipers. There's no obvious way to tell if this is happening, but if the housing and cable are old it's not expensive or difficult to replace them.

There a good park tool page on Canti brake adjustment, you can use this to see what the proper adjustment looks like.

https://www.parktool.com/blog/repair-help/cantilever-threaded-post-brake-service


How to remove a (press fit?) crank arm from a chain ring?

Sorry, those chainrings are riveted in place. You just have to replace the whole crank arm.


Alternating brakes on descents: is it really useful?

I looked at modelling this and it's surprisingly complicated.  There are quite a lot of time constants and heat flows to consider.  If I had a bunch of logging non-contact thermometers I'd consider an experiment.

In practical terms you might want to think about the failure modes if both brakes are working equally hard: If you need to slow down more but both sets of pads/rims/discs/brake fluid are already hot you have less in reserve than if one is cooling while the other is heating -- that last bit of braking might be enough to tip you over the edge.

For a finite length of descent, getting one brake hot enough to lose significant amounts of heat early in the process can help, but heat transfer is linearly proportional to temperature difference,  which will counteract the effect of having one brake hot early. The front brake will get more airflow and so cool faster than the back brake; but if you need to stop you'll need the front brake to work well (and predictably), so running downhill with the front brake lightly on probably isn't a good plan.

For the same total heat input per brake, if the peak temperature of the braking surface is higher it will lose heat into the air faster, potentially (and this is the hard part to model) reducing the transfer to the rest of the system (tubes for rim brakes, fluid for hydraulic discs).  In addition this can only increase the heat lost to air from the working face of the pads as a hot pad touching a hot rim can't give up heat, but a hot pad close to a hot rim with air blowing though the gap can. This is more applicable to rim brakes as the airflow over the pads in a disc sysyem is tiny -- clearances are smaller and there's often a mechanism blocking the airflow. Most pads have poor thermal conductivity meaning little or no heat out the back (sintered metal disc brake pads are an exception).


Assuming you've got modern brakes, the complex cable run you'd have to set up for this likely makes it not worth it to try for cable splitters.  The splitters (daVinci Easy-Split, Bruce Gordon QS2, etc) require a bare cable run, so you'd need a pair of cable stops between the front brake and the front brake lever, not found in most modern setups.

Even if you didn't have the housing running underneath the bar tape, you'd still need to loosen the cable to remove it from the brake, and re-tightening your brakes each time to enable a bar swap would get old quickly. It's not the case that swapping bars and stems frequently would put undue wear on those components, but it certainly increases the chances that you'll over- or under-tension parts at critical moments and cause a failure.  Particularly if you're swapping stems you would need to be mindful of headset preload.  If you end up unbolting and rebolting cables frequently you would increase the wear on them, as the clamping force deforms them and will cause them to fray.

If your bike has cantilever or centerpull brakes with split cable stops you could set up two complete cable runs that wouldn't require you to disconnect the brake cables, but that's unlikely on a modern-ish road bike.


Shimano Nexus 8 IGH : recommendation or changes in bike setup for high altitude ride

It sounds like your hub needs basic service and you'll likely be fine. It may just need bearing adjustment, but on a used bike it's a good idea to go a little further to make sure all is well.
Take it to a shop that's proficient with modern IGHs and ask for a dunk. The Shimano hubs are intended to have their core pulled, externally cleaned, dunked in an oil bath, certain parts greased, and the core reinstalled and the main bearings adjusted. While you're in, you can get a visual that the pawls and gears are looking good (every once in a great while you see a broken one, and they can typically be replaced.) The bearing races can also be inspected, but it takes a lot to mess them up on Nexus hubs. I've only really seen it much in maritime poor storage/maintenance type cases. The whole thing takes maybe 30-45 minutes, a lot of which is spent getting things clean. If there are problems that really warrant replacement, the shop will typically not charge you for the time spent to figure that out if you do them the courtesy of having them do the replacing. But that's not usually how it goes.
Shimano has lowest allowable gear numbers for all their hubs. This is their way of keeping you from breaking something by putting too much torque through the parts. Ask the shop to get you that gearing setup. They may do it by changing either or both the gears, depending on the bike, clearance considerations, what you have now, etc.


What is the foam tube on the top of bmx frame for?

It's to ensure that young boys who ride BMX bikes will be able to have children when they grow up.

Fine print: More accurately, it’s to assuage the worries of the parents that are buying the BMX for their young male child that they might not have grandchildren. Actually efficacy for such purpose is under debate.


Probably not a Claud Butler or a BSA, as the headbadge is the wrong shape.

The name on the handlebars and use of Benelux and Iscaselle suggests Italy (and Sturmey was big in hub brakes everywhere, so may not be British-made).


Here are a couple of insights about getting started, that might be helpful.
1.  Use walking sticks for a few weeks or months - you will know when to throw them away.
2.  Get good body armour - I particularly recommend Kris Holme gloves.  You will also need knee and elbow pads, and a good helmet.


Can I Upgrade shimono Ultegra 9 speed 12-27 cassette

It depends on your rear derailleur. For 11-34 you will need a long cage one.


Can the Tensioner Spring go Bad on a Rear Derailleur?

The tensioner spring is designed to keep the entire chain under tension, even after it passes the crank.  So, the symptom of a too-weak tensioner is slack in the chain between the crank and tensioner.

It sounds like the distance between chain links is not quite the same as the distance between valleys in your sprockets.  This is not unusual if you replaced a very worn chain (because the sprockets would have worn to match the old chain).  It's also not impossible that the sprockets are worn not quite enough to match the old, worn out chain, yet still worn too much to match the brand new chain.  You may need to replace the rest of the sprockets in the cassette.


How do you remove the sprocket from an eighthinch splined BMX style crankset?

Tap tap tap tap tap.

And then tap tap some more.

If this is what I am thinking of you either tap the inside of the chainring from the non drive side. Or you tap the spindle from the drive side which should push the spindle through the chainring and bottom bracket. Or a little of both.

Tap tap with a wood block.

Greasing before install goes a long way to make these things easy. They are made to be tight!

You could improvise a automotive gear puller but the hammer should work.


Smaller chainring on the right side of a bigger one possible?

I've done the chain-setting by hand for a couple days when I was waiting for a replacement front mech to arrive.  It worked, but without a FD cage the chain could bounce around and fall off at bumps, like coasting through gravel.

Also, setting the chain while riding was awful-risky because you're bent right down to reach your chain. It gets old fast, and every time risks catching a finger or missing something going on in the traffic.  Plus you get dirty fingers/gloves.

You already have the solution of a front derailleur.  The only perceived advantage is getting a straighter chainline in the big ring.   So the fix there is to use a triple crankset, and set your big ring in the middle position, leave the outside position empty, and put a middle ring on the innermost position.

The only question here will be finding a FD that moves suitably - you may need to mount it higher up the seat tube than normal, and possibly require a friction shifter not an indexed shifter to get the chain sitting right.

I have a shimano alfine 11 with a 22/34/44 triple, and I have never needed the granny ring even when going up a 15% gradient.  The granny 22 tooth simply didn't give me the 4~5  km/h minimum speed I needed to keep balanced, so it was necessary to apply power in 34:gear1 or 25 gear inches, rather than down in the sub-20 gear inches ranges.


I agree with Daniel’s comment, I’ve had success with using vice grips to hold spikes myself. Be careful not to use excessive force to prevent crushing the spoke. It may help to add a small “flag” made of tape to each spoke to help visualize spoke vs nipple rotation.
Matt’s suggestion of using penetrating oil and heat is a good idea, provided you removed the tube/tire and rim strip first like Daniel suggested. Brass does in fact expand more than steel when heated.
Of course, be sure to use a high quality spoke wrench to prevent rounding the nipples.


Why are almost all bicycle tyres cross-ply/bias ply and not radial construction?

Radial bicycle tires are very rare. The reason is that the lateral stiffness is much lower than for cross-ply tires. Imagine that you press the sidewall of a tire by your thumb. With a cross-ply casing the cords on which you apply pressure are anchored to the bead wires over a distance of about twice the tire width and the whole section shares resistance to deformation. In case of a radial tire the cords run in the same direction as the force, hence offer very limited resistance. Radial tires are prone to squirming and unstable cornering.

Yet a few manufactures still offer radial tires. I know of the Vittoria Diamante Pro Radiale 700x22 for road bikes and the CST Sensamo Speed 35-622 for touring bikes.
The riding experience with the Vittoria tires, published on https://cycletechreview.com/2012/reviews/vittoria-diamante-pro-radiale-tyre-review/  , suggest that they might please persevering afficionado's.
It is probably not accidental that the width is limited to 22 mm. The bigger the diameter, the softer the structure get and, probably, the higher the inflation pressure required for stable load carrying (limited load carrying might be the explanation why airplanes and heavy trucks don't use radial tires but cross-ply tires).

In his study of tire properties, Andrew Dressel included a Maxxis prototype 22-622 tire. He reports (page 113)  'The Maxxis prototype, which is described as “radial” and does appear to have cords aligned at about 22.5º, instead of the 45º usually associated with bias-ply, does not have stiffnesses noticeably different from other tires of similar size.' Here the small width combined with the in-between design would explain the results. See  https://dc.uwm.edu/etd/386/


I have a Dahon Mariner, can I replace 20x1.6" tyre with 20x1.79?

Yes and no.
The width of the tyre is like clothes sizes. What they state is not an exact fit. A brand's 1.79" might measure 1.9" wide and a different brand's 1.79" might measure 1.65".
You need to have a look at your current setup, check how much extra space you have and decide whether the new tyre will fit. Again, if you think it might be a tight fit, having a wider than stated tyre (virtual 17.9" measuring 1.9") may not work.
Having mudgards also affects what width tyre you can use.
So I suggest you look at how much room you have to increase tyre size, and take it from there.


Rohloff clicking sound with ratchety feeling

I have a Rohloff and have sent some emails to the factory due to severe oil spill (had to replace the seals, successfully). From what they have told me, the 25ml of oil is more than double the necessary amount for the hub to work fine, since the oil is very sticky and it distributes inside the hub. Even the unavoidable oil "sweating" should be considered normal, they say.

Recently, I hosted a rider which had a very heavy bike, with 40.000+ on the bike, going to Patagonia (South America). He ultimately LOCKED the hub, being only able to push the bike, not pedal forward or backwards. Rohloff replaced the hub for free, but he had to travel to the capital 1600km away to receive the package :o(

I doubt very much that lack/excess of oil is the problem. I agree with what folks are saying about the chain/sprocket (either too tight or otherwise defective, with a frozen link, or a bent chainring tooth).

What I suggest you is to isolate the drivetrain from the problem: be sure the chainring, chain, sprocket and chaintensioner (if any) are not generating the click.

If not so, write to Rohloff describing your problem as thoroughly as possible, they are VERY supportive.

The not-so-good news is that Rohloff, besides being a marvel of engineering indeed, is not as nearly as bomb-proof as a lot of fanboys tend to propagate, if it is used hard for a long time, some part replacements are unavoidable.

And even with Rohloff, some defects can appear, and the exact building of the hub has changed over the years to avoid common patterns of failure detected.

Unfortunately, it is not possible to be sure if the hub is defective or not, at least via this site, but I hope this helps. Any question in the comments, and I'll be ready to answer.


Compatibility of bar end shifters and 10 spd Tiagra

With Tiagra in particular this answer is different from if your bike had any other 10-speed group.

Presently there are two different 10-speed Tiagra generations, 4600 and 4700. (So the STI from one is ST-4600 and the other is ST-4700, etc). 4600 uses the same classic actuation ratio that all pre-11-speed Shimano road groups used other than first generation Dura-Ace. 4700, however, is an oddball group. It's 10-speed but uses the new 11-speed actuation ratio, resulting in a situation where ST-4700 is currently unique in Shimano's history in terms of number of clicks (10) and amount of cable pulled per click. No other shifters interchange with ST-4700, including any of the bar-end models. So if you have 4700-level Tiagra the answer is no, there's no way of doing this. You would have to also get a new rear derailleur from any other 10-speed road group, like for example RD-5600, RD-5700, RD-6600, RD-6700, RD-7800, or RD-7900. Then it will work. (The front derailer will be friction so no issues there - otherwise it would also have a cable pull issue.)

It hasn't become clear yet whether more 10-speed groups with 4700's cable pull will be released, but I wouldn't wait for a bar-end version.


Chain guards for front derailleurs: Metal alternative to SKS chainboard?

I doubt it exist over the shelf.  It's already hard to find one that's made of plastic.  If you really are set on going metal I'd suggest keeping a single chain ring and focus your gearing in the rear (hub, cassette, or hub+cassette combo).  Building a custom chain guard will be costly, a pain, and not guaranteed to be a success.  If you really want to have some gearing in front you could look at the SchlumpfDrive but at these prices you could also just get a Rohloff.  Both should work fine with the standard metal chain guards.


Microshift Advent rear derailleur cable pull ratio?

ANSWER The numbers aren't available, but it is not an existing standard.

Their own advertising at https://www.microshift.com/en/product/sl-m8195-r/ says

  Compatible only with ADVENT rear derailleurs
  Not compatible with Shimano or SRAM

Also found this quote from a microshift guy named Patrick  February 20, 2019 at 2:05 pm

  Proprietary cable pull actually wasn’t our first choice. microSHIFT has always played nice with cable pulls in the industry. (Check out our thumb shifters and bar end shifters) We have been Shimano compatible for a long time, but we don’t do it this time for good reasons.
  The early prototypes were designed around traditional 9-speed cable pull. It shifted very poorly. The leverage arm on the derailleur just wasn’t long enough to move the chains up the bigger cogs. This proprietary cable pull pulls more cable to have smoother shifting and have a stronger clutch at the same time.

Details:

Turns out this is not a common microshift part that duplicates the specs of an existing Shimano or Sram system.  Instead they've produced a 1x system with 9 speeds stretching from 11 tooth up to 42 tooth.  Its not a full groupset, only includes a rear mech, shifter, and a cassette.

Advent is chain agnostic - meaning it will work with any 9-speed chain.
Rear mech has a clutch like all the other new models.
Cassette fits a Shimano HG freehub body, so no new wheels required.

Note the rear mech looks different - the cable path is barely a right-turn compared to a 180 degree turn of other mechs.  If your gear wire came down the chainstay it would be a straight cable path into the rear mech.

Aside - I don't know how this would work if you wanted a double or triple chainset on the front.  That would not be a part of this groupset so it will be Shimano or Sram or whatever, and will use a different cable pull again.  Upshot: the left and right shifters on your bike will be different brands and probably styles.

Though I successfully run several bikes with a friction shifter for the front and whatever for the rear mech - no bother at all cos you're never changing both simultaneously.


It sounds to me like your four rubber straps are to hold the bikes together more tightly unless they're used to clamp the frame to the carrier.

The missing security strap is an anti-theft cable. Robberies from the backs of vehicles seem to be on an increase and any deterrent you can put in place to prevent theft is worthwhile.

In this case, the manufacturer is deferring the anti-theft security over to you so they are not liable if your bikes get stolen f I'm the rack.

When you're mounting your bikes, it's worth using some old rags or similar to help prevent rubbing and scratching in-transit too.


How do I prevent my chain from dropping down while going downhill on bumpy surfaces?

There is no easy and free solution for this, since your bike is not meant to be going downhill.

The best thing you can do is go downhill using the largest front chainring and a pretty large rear cog (but not the largest). This will ensure a pretty good rear derailleur tension which will most probably prevent the chain fall.

If you are willing to spend money on this you could convert to 1x10 or 1x11 (after making sure that the gearing will be good for your rides) and use a narrow wide chainring and a derailleur with a clutch mechanism.


Crankset replacement for TERN Verge D9 (9 gear folding bike)

The first thing I'd do is contact Tern and see if they can supply a replacement. That's the easier way to make sure you get a compatible crank.
I don't think it's possible to buy Prowheel components directly (at least they didn't show up in a couple of online bike retailers I tried) so you need to find a compatible replacement. From the Tern Verge D9 web page we can see that the crank is single ring, 53 teeth and fits on a cartridge type bottom bracket - presumably with a square taper axle-crank interface. The info written on the crank tells us it has 170mm crank arms (measured crank spindle center to pedal spindle center). The tooth count and crank arm length you can of course verify.
You can search for folding bike cranks that match these specs. An alternative is to look for 'track cranks' (used on single speed velodrome track bikes). These may be easier to find but typically have smaller chainrings, but you can also find replacement chainrings that match the bolt pattern and circle diameter.
The complication is that each crank model requires a specific bottom bracket axle length to get a specific chainline - how far away from the center line the bike frame the chainring is. It can be tricky to find this info for cheaper and non mainstream brand cranks. You may need to replace the bottom bracket with one with a different axle length to get the right chainline.
Special tools are required to get the crank arms off the axle tapers and to remove and install a cartridge bottom bracket from the frame. Additionally everything really need to be installed with a torque wrench to make sure bolts are tightened to proper specifications.
On that subject, threads in the crank arms can get deformed and ruined if the pedal spindles are not tightened properly. The hard steel starts to wallow around in the softer alloy crank threads. That's probably what happened to you cranks.
If you are not familiar with bike repair (presumably you are not, as you're asking here) you'll need to enlist a local bike repair shop to help you install the crank, and they will of course be able to help you source a compatible crank.


New bottom bracket and crankset - what spindle length?

Chainline is important, more so for modern 10+ speed systems. A six speed system is more forgiving of misalignment than one would guess. Since both BB are square taper all you need to do is remove it and see what the size is on the BB itself. The shaft will only allow a crank on so far (that's why its taper). By buying the size currently in the bike you should come pretty close. You'll see plenty of cross chaining with modern bikes and they survive. Although not the same exactly, I think you'd be OK as well.

(Not so cheap but) Simple Solution:
Why not just replace the chainring if it is that worn? Much easier to do, and much cheaper. Also, if your chainring is in that bad of shape it is likely your freewheel is damaged too, as is the chain. You'd be better served by replacing the drivetrain entirely. Removing freewheels are not as easy as hubs, but it can be done. You'll have the ride you wanted without the compromised components causing mischief and making you think it is a chainline issue.

Good Luck!


what to look for when buying bicycle pants

They should be elastic enough so that you can move your legs freely in all directions when you are trying them at the shop.

Padding is very important, but some models can make it very uncomfortable out of the bike. Nowadays, there are some anatomical paddings which, instead of being made of a single patch of padding, are made of lots of geometrically shaped patches of padding of different materials. These work great. If you try a short at the shop and it feels uncomfortable, most probably it will remain uncomfortable.

The stitches and sewings must not have sharp/stingy textures that might annoy you a lot while pedalling.

Good quality usually is associated to larger price, and the opposite.

And, you MUST try as many models you can at the shop. The most comfortable at the cabin most probably would be the best for your ride.

I wouldn't buy one online or preorder, unless I had one identical already in use - and they may change the product without notice!


How to find a model number that replaced an old Shimano part

I hate to say this, but You're going to have to make a trip to your local bike shop. Chances are, if they're in the US, and they carry Shimano parts, they buy from Quality Bicycle Products (QBP). The company has an online catalog which you can search part numbers both active ant inactive, as well as related models. This catalog is only accessible to bicycle shops, and not the general public (though feel free to open your own shop, we only need more of them :-) ).

They'll be more than happy to assist you there, and hopefully find you an answer.

Now, buyer beware that this is only a guess, but based upon the internal levering mechanism that you describe, the BR-M580 looks to be the successor in the LX parts line. I see the same mechanical features, but from an upgraded parts standpoint. Like I said, only the parts shop will know for sure.

Now onto the actual question; the process. The shimano parts website holds a database of some of their part numbers. I simply searched your part number preceeder, the series, and the line (eg "BR-M DEORE LX") and I sifted through the disk brakes, and found similar pad brakes in a higher line.


Back wheel rubs against the back brake pad when riding

If it's rubbing while riding, but not when you're off the bike, it's either a spoke tension issue as noted by @earlgrey, or, you could have loose bearing cones that are allowing your wheel to flop around. Either way, a dangerous condition that you should have a local shop look into.


One-wheeled trailers are more agile and don't increase the width of your bike.  They lean with the bike. If you're going to go really narrow places, you need one-wheel.

Two-wheeled trailers can generally carry more weight and are less prone to making the bike fall over when you stop.

So, what are you going to do with the trailer?  Going up and down mountains with narrow trails: get a one-wheeled trailer. Carrying 50kg of equipment from the hardware store home using streets and wide paths: get a two-wheeled trailer.


Can my belt drive frame be converted to a derailleur setup?

There is no good way. One could imagine ways of contriving a low-end claw-type derailleur on. Don't do that.
Nexus hubs are usually reliable. In some places in the world, there are lot running around without issue. That you've had chronic issues suggests either damage, defect, or a setup issue.
Some number of Nexus and Alfine bikes have made it into the world with mismatched cassette joints and shifters from the factory. It is a maddening problem until you've figured it out.
There are steps between what you have now and Rohloff, if it came to replacing the hub. I recommend taking it to a shop that really knows internal hubs. They are robust but have their quirks and unique procedures and things to check.


I just mounted the 34t cassette and it works fine.

I also tried it on an even older but same length DX derailleur and it worked there as well. Only using it for road and not MTB. Not sure if that makes any difference.


Mild pain in lower forearms during biking

Fatigue indicates you are using the muscle, so you will need to “check into” yourself to see how/why you are firing your forearm muscle, what task is it trying to accomplish.

Sometimes we just have some odd or peculiar habits we are unaware we are doing. For example, my wife used to complain about wrist and hand pain when riding her flat bar commute bike until I observed she held her wrists in heavy dorsiflexion when she gripped the bar. Retraining how she held flat bar grips (i.e., a wrist angle of zero) alleviated the symptoms.

Finally, as other answers indicted some component of bike fit could also be the culprit, but there is not enough information to comment on this possibility.


belt vs chain for what matters performance only

First things first: A belt is probably slightly less efficient than a properly installed clean chain. The test you link already indicates that. Probably with the tension Gates requires you'll loose a bit more power.

On to your question:

The chain is 200 grams heavier than the belt, of course with the chain you get gears, which you don't get with a belt unless you also install an internally geared hub, which changes the weight of the entire drivetrain heavily the other way, but lets disregard that for now. You loose 200 grams, and you loose 1 watt. From how big a pool do you take that watt? Just to grab something, take a number from here for a cyclist doing a timetrial of 10 miles in 30 minutes: 157 watt.

So this means 1 watt is a loss of about 0.66% for a reasonably fit recreational cyclist.

Given that a reasonably fit recreational cyclist weighs about 80kgs, has a bike of 10kgs, and is carrying 3kg of clothing, gear and filled waterbottles, the 200grams (0.2kg) you save translates to about 0.22% weight loss. So we can already conclude that the weight gain would never compensate for the efficiency loss.

However, when going at any sort of speed, weight is not the factor holding you back, air resistance is. So unless you only bike up the steepest parts of HC climbs in your riding the reality is that the weight loss from a belt drive will never compensate for the efficiency loss.

As far as I can see, the reasons for switching to a belt drive (probably combined with something like a rohloff speedhub) are:

Less maintenance
Less dirt sticking to all the oily bits (belt stays clean longer)
Efficiency degrades less over time between cleaning intervals (meaning a dirty chain is a lot less efficient than a dirty belt)

As a year-round bicycle commuter I can tell you that without a doubt a belt-drive combined with an internally geared hub is way more efficient with my time than a chain could ever be. I loose maybe a few seconds over my 15km (one way) commute (if that) but I gain hours by only having to hose my bike down every other week rather than cleaning and re-oiling my entire drivetrain every few days.


Rear wheel not spinning when the skewer is locked in

When you cleaned the rear hub, did you reassemble it in the right order?   Sounds like your axle is too far over, or there's possible a lock nut in the wrong place, so that when you cinch down the QR, the dropouts are touching the axle (OK) and the wheel hub (not OK)

If the wheel spins okay on its axle/bearings when off the bike, then something about fitting is making it bind.  Check your brakes and both the chainstay and seatstay clearance points when the wheel is fitted.  Hang the bike up and slowly spin the wheel looking at each point to see if the wheel is rubbing at some point - it may be out of true.


How can I spin a dynamo wheel at road speed for bench testing?

Sounds like you have the same requirements as the Rubbee, which is a small wheel pressed against the tread of the tyre.

Have you got an old inner tube (perhaps a 2" MTB sized one) where you can cut a slice off, and mount that over your drill's chuck?

If the diameter of the chuck isn't quite large enough, a wooden disk with a larger radius could be mounted in the chuck with a bolt on the disk's center.

Don't forget that some drills have gearboxes with multiple stages.  2 speed is common.

A last resort might be to disregard any battery powered drill and check the effective RPMs from a mains powered drill.

I've successfully mounted a spoke magnet in my pillar drill and used it to test a bike computer sensor.  (It topped out reading 150 km/h)


Creaking from the BB area can be hard to localize, but there are basically 5 sources:

The cups holding the cartridge in place are a hair loose, and the cartridge is moving around a bit.  Not a real big deal but should be fixed.
The BB cartridge bearings are going bad somehow.  Unlikely.
A pedal is making noise.  Sometimes this is indicative of a bad bearing, sometimes it's just what the pedal does.
The pedal is loose where it's screwed into the crank arm.  Needs to be fixed fairly soon, or the crank arm can be damaged.
The crank arm is loose on the crank axle.  This is a serious problem and needs to be fixed right away (if not sooner) to prevent damage to the crank arm and the axle.


What is mysteriously slicing the inside of my tubes?

I agree with your diagnosis: it must be related to the rim tape.

Take it off and inspect it and the rim below. If you don't find anything obvious, buy new, good quality rim tapes, check there are no sharp edges, and reinstall.


What do I get by paying more for a bicycle?

With so many good answers I hesitate to say anything.

But, in an effort to add something useful to the conversation...

The Value Curve
Part of the reason it's hard to understand the difference between more and less expensive bikes is that you do get what you pay for, but cost increases faster than value.

What is Value?
For the purposes of this answer I'm defining "value" as some measurable improvement.
For example, a $15 steel chain that will last 3,000 miles vs an $80.00 stainless steel chain that will last 8,000 miles (made up numbers - this is only an example)

Why is There a Curve?
The cost to manufacture increases faster than value. Each improvement cost more to manufacture than the last one.

For Example
It's easy to see a difference between a $50.00 bike and a $400.00 bike.
It's harder (not impossible) to see the difference between a $800.00 bike and an $1200.00 bike.
As price goes up it gets harder and harder to see an increase in value.

I would argue that at some price point there is no value increase and you are paying (hopefully) for craftsmanship, like extra polish or fancy lug work or exotic materials that are expensive but don't contribute to a measurable difference.

Suppose I agree that there is a value curve - what should I do?
There is a "sweet spot" in the curve. A place where you get the most bang for your buck. The problem is that I can't tell you exactly where that is because it changes over time and it depends on the individual's situation - finances and type of riding.
Bike shoppers have to balance their budget with the desired level of performance and decide where their sweet spot is.

Always test ride bikes before buying. Always ride more than one so you can compare.
A parking lot is not a great way to compare ride but it's much better than nothing. Bike feel matters.


Are all Cannondale Slice forks compatible with a Cannondale Slice 105 frame?

Doesn't need to be a cannondale fork, just needs to be the right diameter(s) and long enough to get out the top of the frame and be clamped by the stem.

Check wheel mounting tech and brake mounts too, but you can use any fork that fits.


Can I use Shimano trigger shifter with my X3 SRam gears?

SRAM X series and most (all?) of the road stuff has a 1:1 ratio. Shimano is (I believe) 1.5:1; you are asking for drive-train tuning hell if you mix.

Cassettes, mix all you want. Shifters and derailleurs should be matched.


Degreaser and oil recommendations for Nexus 8

Don't use degreaser on the insides of an IGH! Not! Ever!

For Shimano Nexus/Alfine you are supposed to use the same oil for cleaning and lubrication.

For Rohloff there is a separate cleaning oil which I think has lower viscosity than the lubrication oil.

Also you replace the oil at most once a year or every 5000km, not more often. Some hubs might need their very first oil change earlier, like after 1000km.

This assumes going though the bleeds nipples like normal people.

If you are going to take the hub apart completely (not just remove the gear block from the housing) this doesn't necessarily apply, but taking the hub apart is not something even good bicycle mechanics do. It never makes economic sense. If taking it apart and fixing it is cheaper to you than having it replaced, then it didn't make economic sense to buy it in the first place and you should have gone with something cheaper, simpler, more mechanically elegant and more maintenance intensive - as in, much less maintenance than taking apart and fixing an IGH.


Trying to identify part name and correct bolt size

I disassembled two that were readily available, one on a Giant and one on a Specialized. Both use an M8 x 18mm. The 18mm  length dimension did not include the head of the bolt. The total length was 24mm. I also noted both bolt heads were slightly shorter than industrial standard. Visually it looks like a bolt with a taller head would work but  1/2 head would  be exposed. Most small components of sub-assemblies aren't readily available the entire part would need replacement.  Although sometimes a local sop might have something in a stray parts bin. In your case since you only lack a bolt, any local supplier should be able to supply something that will work.


No you cannot. The Hero Cyclone does not appear to have a hanger / mounting holes for a dérailleur. You may be able to install an internal gear hub, but it would likely cost far more than the bike.

You may be able to find something used though.


The bigger problem here isn't the width of the rim, it's the sizes of tires made in that ISO.  As mentioned in the comments, frame width is another restricting factor.  Junior Cruisers are made for junior riders.  If he's outgrowing it, it may be time to switch up to standard Cruiser or Pro 20" class.  To answer your question, 507 ISO rims are usually between 19 and 24mm wide.  They will run tires from 24x1.25 up to 2.25 and a little bigger for the larger side of the range.  One other consideration is brake position.  Make sure you can get brakes that will reach the(farther) rim position.


You need to push both pistons at the same time. There are tools for doing this, but many of us use a large flat bladed screwdriver.

You need a steady firm pressure for a few seconds to force the fuild in the lever back into the reservoir.
Have a look at this Park Tool video - about 4:10


Rough estimate of distance of tip of derailleur cage from axle center:

I assume top pulley wheel is just touching sprocket, and pulley centers lie on a radius line from wheel axle center.

The radius through chain pin centers of a sprocket is approximated by n * s / 2 pi. n is number of teeth, s is chain pitch: 12.75mm in this case (see here).

Add say 5mm to pin center radius to get approximate total radius of sprocket.

40 teeth: 86mm

42 teeth: 90mm

46 teeth: 98mm

XTR RD-M9000 derailleurs have 11 tooth pulleys (I think)

11 teeth: 27mm

The distance of the tip of the lower pulley wheel from the wheel axle center is sprocket radius + (2 * pulley radius) + cage pulley center to pulley center distance.

Guessing the pulley center to pulley center distance is 80mm:

40 teeth: 220mm

42 teeth: 224mm

46 teeth: 232mm

How much clearance between the axle center and road do you have? An ETRTO 406 rim is obviously 203mm radius, plus say 25mm tire depth for a 35mm wide tire: 228mm.

There are plenty of 20" wheel folding bikes with derailleurs available, but I assume these use ~30 tooth largest sprockets. Browsing through google images of folding bikes I see their derailleur cages are very close to the ground anyway.


If you really want to find out, look for a local time trial route and see what people can do on that.
There's also an advantage coming up behind someone - not so much the aero advantage as you have to get close for that, but the knowledge that there's someone to catch up with - your head goes into race mode, even just a little, but theirs doesn't.
Some riders have all the gear but no fitness. Others are having off days. I've seen the effects you note from both sides. Within the last few days I've blasted past 2 roadies uphill while on my shopping bike with a big backpack, and struggled to make much headway at all on my faster but still heavy bike after wearing myself out earlier in the ride (140km with some rough gravel). Flat out on the TT course near me I might average 21mph for half an hour, commuting on the same bike little more than half that unless I'm rushing to get somewhere. But my fast pace would be almost last looking at events on that course; winners are 50% faster than me.


How can I test gloves for long ride comfort?

When testing for something, you wanna make sure you are providing the similar environment for testing as for use.

Exhale some warm moist air on handle-like things, make sure you warm your hands up to the maximum extent by rubbing vigorously, hold them firmly for next 5 or so mins (doesn't matter riding or not).

This'll let you judge 3 things basically:

How they deal with sweat, is the grip impacted!
Is the cushioning sufficient, because we generally don't make such tight grips continuously while riding.
When you remove them and touch their palm side with bare hands, their temperature will tell you about material too. if they're properly ventilated or not.


What is the brand/model of my bike frame?

I see a 1970s steel framed road bike of decent quality.

It has cottered cranks which went away before the 80s, and it has quality centerpull brakes.

I can't guess the maker, but it smells like a European bike to me.  The Woods valves may imply Dutch or English or Japanese, but its just as likely to have had other tubes fitted over time.

There are some brake bits and gear shifters missing and parts that need replacement like tyres and tubes, brake pads and probably chain.  However its 97% there and could be easy to get going again.  Main gotcha is the condition of wear parts like headset and wheel bearings and BB races.

The side photos show a fork with comparatively little rake on it compared to the era.  So this bike would have felt lively and easy to turn.  That reactivity would be valued in a race situation, but less so on a commute or long-distance bike.

Note the quill stem seems to be raised up a lot - Do check the minimum insert line is down and not visible.

Totally loverly bike.  You could do a bare-minimum fixup and ride it, or you could do a full-on restoration with re-chroming and everything.  Whether you stay with 27" wheels or go for the slightly more modern 700c wheels will depend on whether the brakes will reach a 700c rim - you need 4-6mm more reach on the brakes.  Or possibly change brakes for long-reach dual pivots like Tektro 559.


Nice picture. But you installed the dust cover (the silver ring) upside down. They way it works is that the bearings sit underneath it (but do not make contact) and are protected from all sorts of insults and wear. It keeps the grease in, and the bearings in place while servicing it.

The way it is now it will not allow for the race to be adjusted against the bearings. It's got to come out.

In the future, buy a small magnetic pick tool from a parts store. It makes digging out the bearings much easier and you won't be tempted to take it out. It's kind of a pain to get in there just right.

Good luck!


Columba folder w/mountain 10sp cassette & Sram X7 derailleur

That shouldn't be happening - it sounds as though you have the wrong hanger on the bike. If you have replaced the hanger (or a previous owner has) they have probably used one that fits on the bike but isn't correct. You may be able to file it down to fit, but it's better to buy the right hanger.

For your second question, it's definitely possible to swap out a QR axle for a solid one. The threaded part of the axle is the same for both, so it's just a matter of getting a solid rear axle and swapping the bearing races and so on over.

If you get that done at a bike shop they will probably suggest replacing the cones and bearings, since those are fairly cheap parts and the labour cost of taking the wheel apart is most of the cost of that swap. Once they have it apart if there's any visible wear it's worth doing, and unless the bike is fairly new I'd suggesting doing it. It should add less than $20 to the total cost.


Do Shimano Nexus hubs lose efficiency as they get older?

In the 5 years have you had the hub rebuilt / repacked with grease? The maintenance schedule for the Nexus 8 speed is every 5000 km or 2 years, which ever comes first (I believe).  If you have not had any maintenance in your 5 years this is likely the culprit for decreased performance.

20,000 km should be no problem for a properly maintained hub; however, if you have gone without maintenance there is a chance you have started damaging the internals though intrusion of dirt and water. I would hesitate to speculate what may be going wrong (perhaps the roller clutch), but there are quite a few parts that all require proper lubrication.

Either way, I would take it to a certified Shimano dealer to have a look over.  They can tell you if the hub is still viable hub, and if so, what maintenance needs to be done.

If you are interested to learn more about the internal workings of your nexus hub, may I suggest starting here.


Should I buy a new bike rack if my current one has been bent?

Without entering too much in material science, when a metal is permanently deformed it is because it has worked out of its elastic region and has gone into its plastic region.

This highly reduce the ability of that part to absorb energy, which is highly desirable in all the impacts.

Though somebody may have straightened it back, it can always happen that as soon as hit a bump or have a sudden load on your rack, it will bend again, with obvious consequences on your stability.


Rode on a flat tire - how do I check for possible damage?

The wheel is unlikely to have suffered any damage, unless you experienced a really hard bump (for example from going over a big stone at full speed). Just to be safe, check the rim for damage (such as dents) and make sure the wheel is still true.
The tire itself is most likely to have suffered. By running on a flat tire, the tire is subject to much more flexing than when inflated - in the long run, this will damage the tire. If the tire has deep creases or is torn, especially on the flanks, you will have to replace it. Otherwise it is probably ok to use.
Finally, make sure the inner tube did not suffer a puncture, and replace it if it did.

With these precautions, you should be ok.


Am I better off buying a new bike, or upgrading my old bike?

As @Daniel said - I would suggest looking for a newer second hand bike closer to what you want. the cost of components, along with compatibility issues, will like make the exercise more expensive with a bike that has a few niggly problems that just won't go away.  However, it you are particularly attached to the frame, it might be worth while. Consider getting a donor bike, as whole bikes are usually significantly cheaper than the sum oft there parts.

If you go down the seconds hand or new path, Jamis (an I am sure others) make mid and high quality steel bikes (Look for the Dragon range in MTB) for those of us that appreciate the advantages of steel. At the highest end, the weight penalty is so small it can be ignored.

Edit :  List of steel road bikes


Bike Information
Here's a thread on the acquisition and rehabilitation of a U-Haul cruiser.

Summary:

  I saw the UHAUL stamping on the BB, the Made in Taiwan gold decal, and the FBC stamp on the rear dropout. With a little research and help from forum members it was determined that its an early to mid 80's Taiwanese built bicycle specifically for UHAUL.

Evidently U-Haul had special made bicycles to rent.
Since they were "Not To Be Sold" one might wonder how they wound up in the wild.

Another thread with informative pictures.

Key Information

  FBC is Fit bicycle company, 1990’s pre China made in Taiwan.

Fully restored

bmxmuseum.com

  In the early 1980's U-Haul ordered X amount of these bikes from FBC (not Fit Bike Co) so they could be used as rentals. They are stamped UHAUL on bottom bracket and FBC on rear dropout. There are only 3 known survivors in the USA currently out of 4 that have surfaced in the last decade. When it was new the bike was originally equipped with a Shimano 333 3-speed hub, bear trap style pedals, MX caliper brakes, 7X rims, Snakebelly tires, chrome cruiser bars, and a Persons spring seat like the one on Pee Wee Herman's bike.

Bike Value
We don't offer valuations.
A bike is worth what someone will pay for it. Since that changes over time the information becomes out of date. We hope to provide information that does not go stale.


Looking to change from Octalink Claris to Shimano 105, will the frame be compatible with a 105 hub?

Octalink is the bottom bracket spindle interface. It's kind of muddying the waters to focus on this. If you have all Claris parts of that era, the commonly understood way of referring to it would be 2400, Claris 2400, etc. (There's a newer Claris now.)
Straightforward modern rim brake road bikes like that generally can have whatever group you want dropped in. Going to 11 will mean needing a new rear hub/wheel in most such cases. It should be fine.


To add a rear disc brake you must have a frame with a disc mount. You will also need a rear wheel that has a disc compatible hub. Unless you find a really good deal on something used you will spend more than the bike is worth. If you feel the rear V brakes were insufficient, your money would be better spent getting quality shoes for the rear. Some riders claim good quality V shoes work as well as low end discs.


Do I need to protect my bike from jostling around if I put it under the bus?

With other items sliding around I'd suggest a case where you don't need to take the bike fully apart to pack it. I think there are some you can just take the front wheel off of and pack it. If you can't do something like that you could use bungie cords to secure it and go to the hardware store and get some foam padding to put around the frame and drivetrain. It's not 100% but it'll manage the risk a bit more. I'd be less concerned about the frame snapping or bending and more about derailleurs breaking or spokes breaking.


Replacing crank and bearing on cheap Murray

There are many levels of "upgrade". To be "better than the junk it came with" there are at least two options with many shades of quality level.
1. One piece crank upgrade
There are different qualities of one piece cranks / bearings / cones / races. Murry, Huffy etc. come with the lowest quality.
Back when Schwinn bicycles were made in the U.S. Schwinn bicycles with one piece cranks came with good quality crank parts. "New Old Stock" (NOS) Schwinn bearings, races, cones, and crank would be an upgrade to the parts you removed and they will fit your bike. Other sources for quality one piece crank parts would be made by Tioga, Tange or some other name brand maker.
As with anything there are advantages and disadvantages to a one piece crank. They are easy to maintain, they are very strong - they are also very heavy. This would be the least expensive upgrade.
Sheldon Brown has a nice over view of one piece crank types and interchangeability.
2. Three piece crank
The video Argenti has posted demonstrates how to replace a one piece crank with a very nice three piece crank and sealed bearing setup. There are a variety of solutions offered by different companies to accomplish this with a wide range of quality and prices. They will reduce weight but I would argue that a good three piece crank is no stronger than a good forged chromoly one piece crank.
As you convert your Murry into an e-bike remember that the quality of crank parts you removed are relatively equal to the quality of parts on the rest of the bike - including the frame.
Murry designed the bike to be affordable and to do that they compromised on the durability of the entire bike, not just the crank parts.
Adding an electric motor to a bicycle introduces forces the bicycle was not designed for. Using a low quality bicycle as the basis for an e-bike is especially problematic and could be dangerous.


Can I install 11 speed cassette on 10 speed hub by skipping last cog?

Shimano road 11 speed freehub bodies are not simply 1 sprocket wider than a 10 speed freehub body.

The 11 speed body is just 1.8mm wider than the 10 speed body, 11 speed sprocket spacing is less than 10 speed to fit the extra sprocket in (and I'm guessing there there may be a little more overhang of the freehub body flange).

You cannot remove the biggest sprocket as is it affixed to a spider. You might be able to get away with removing the smallest sprocket, if you can find a spacer of the right thickness to take up the extra space this leaves.


I suggest buying a regular road bike, have it properly fit and ride it.

It will be good enough for a couple of years in all situations, not just triathlons.

You can upgrade it with some aero bars, better wheels and tyres.


What kind of tool will loosen this nut holding a chainwheel on a one piece crank?

Such a tool may be called hook spanner.

The nut is holding the inner race of the bottom bracket bearing.

A web search with "bottom bracket" and "hook spanner" produces a couple of hits. (For instance, the tool mentioned by Klaster in the comments.) You may use a vernier caliper to determine the dimensions of your nut and find the right tool for you.


Negligible difference. More expensive pedals will have higher end bearings which should spin better, but what you're really getting there is a bearing that should last longer. The more you pay for a pedal, the lighter it should be and the longer the bearings should last. That's really it.


Can I use a 3x10 or 3x9 speed (front) chainring in a 3x8 speed drive?

In almost all cases it can be made to work fine. The trick to getting there is that because the ring can be a little thinner due to the the narrower ring-to-ring spacing of the crank it's intended for, you sometimes need tiny little chainring spacers/shims to get the centerline of the ring spaced where you want it to be. With a large ring, the other issue that often comes up if you don't have them is the chain may rub on the inside of the new large ring when you're in the middle ring, small cog combos. It's pretty common to see this being the main functional issue in practice.

The main flavor of tiny chainring spacers available are the 0.6mm ones from Wheels Mfg and a couple other brands. On paper the .6 can seem like too much, but in practice they tend to work great in scenarios like the one you're in. 0.1mm spacers exist and can be useful for getting things stone perfect, but they're not a standard bike industry item and aren't usually needed. You can get them from industrial suppliers (McMaster etc) if needed. The 0.1s are probably a little more under the radar in the bike world than they should be in terms of usefulness.

The other factor is how well the ramps and pins play together. Usually you don't really have a lot of choices here and it works fine anyway, probably because despite being ostensibly different systems, manufacturers have fairly similar ideas about where in the rotation cycle to locate them. (That is my speculation.) I often gravitate towards using rings intended to be generic replacements, such as the ramped and pinned ones from US distributor house brands Origin8 and Dimension, and tend to get fine results with those. On the other hand, for commuter bikes with 104/64 BCD in particular I often try first the Deore/Alivio level steel rings from Shimano, which are cheap, work good, last a very long time, and can usually be made to work well on any crank of the right BCD.


Using 9 speed bar end shifters in friction mode with 10 speed derailleurs and cassette

Beyond the question of finickiness of actually using the system with higher cog counts, it's a matter of whether there's enough total cable pull from the shifter in friction mode to cover the range of movement needed given the cassette used and the actuation ratio of the derailer.

Here's an excellent article with the basic data you need to figure it out, snipped:

The only other piece you'd need to know is the actual total cable pull of your SL-BS77 9-speed bar end shifters, which requires measuring since 9*2.5 doesn't work because it's got some phantom movement both before and after its normal range of clicks when in indexed mode. I have them on a bike so I undid the low limit, put it in friction, put a mark on the cable and came up with 24.5mm total movement.

So, the answers:

Shimano 10 with a 10-speed Shimano road RD works because 24.5*1.7=41.65 (the total amount of derailer movement you get) and 3.95*10=39.5 (the minimum total range you need, here a smaller number than the 41.65). Shimano 10 with a 10-speed mountain RD doesn't work because 24.5*1.2=29.4.

Shimano 11 with an 11-speed Shimano road RD doesn't work because 24.5*1.4=34.3 (derailer range movement), which is less than 11*3.9=42.9 (range needed). Shimano 11-speed mountain RDs have an even lower actuation ratio (1.1) so we know that won't work either. So in other words, all the 11-speed shifters pull quite a bit more cable, so this friction shifter and probably many others out there in the world can't really sub in for them, primarily because the actuation ratio the systems run on has been made quite a bit different than in the past, plus the cassette itself is a little wider. You could almost do it by just using an older derailer with the 1.7 ratio, but not quite (24.5*1.7=41.65, and we need 42.9). Hacking the cable anchor to tweak the ratio by that much is probably achievable.

Campy 10 with a 10-speed Campy RD won't work, because 24.5*1.4=36.75, and 4.15*10=41.5. But it will work, barely, with a Shimano RD with the 1.7 ratio.


How to re-terminate frayed brake cables?

Seth's Bike Hacks channel on Youtube has a video that specifically addresses this problem:

A quote:

  When I showed the cable fray trick in another video, some of you thought I was playing it in reverse, but it’s true! You can unfray some cables by twisting them from the base and working your way back up. This works particularly well on cables that were recently frayed, and usually by clipping a little off the end and adding a new cap, you’re back up and running without needing to swap the whole thing.


What kind of tire will fit a Columbia touring 26 inch bicycle

The tire brand alone won't help. Over the years bike makers and tire makers have invented an amazing range of sizes. It keeps us on our toes…

I'd guess that the tires you found at Walmart were 26 x 1.375 (or some other decimal size). You'd think that 1.375 and 1 3/8 inches would be the same. Alas, they are not. This question, Why does a decimal sized 26“ tire fit my rims but a fractional sized 26” tire doesn't?, explains in more detail.

What you need to do is to find a tire with a fractional size (or look for a tire marked 35-590 or 37-590 – this is an ETRTO/ISO tire size, the numbers are the width (35 mm or 37 mm) and the "bead seat diameter" of the rim (590 mm). Most tires will be marked with this number and it will let you be sure you're getting the right size.

Your local bike shop will probably be able to get these for you, or if you'd rather order online one place that carries a good selection is Harris Cyclery. The link will take you to their selection of tires.


What is the purpose of this rear dropout screw?

While it has a rotation prevention value, it's negligible really. The Fuji Gran Fondo introduced this system in ~2012. They have a few of their road bikes use this convertible rear axle system.

This system allows riders to swap between a 12mm thru-axle and a 135mm traditional quick release system.
That screw specifically has a female part on the inside of the frame. They pull together through the frame to sandwich the axle receiver (black part in your photo) onto the carbon frame. - This is a common method for attaching interchangeable Aluminum parts onto carbon and is stronger than having a single screw driven into the frame itself. You also have the same on the other side and the sides need to interchanged as a pair. This is a common setup for convertible rear axle frames in both MTB and road.

Now, on the the 12mm setup the non-drive side receiver is round yes. However this side is more of a pass-thru receiver and the axle treads on the drive-side. On that side you have the hanger shape and another off-set screw that actually prevents the rotation as you tighten.

In short, I don't think you will ever be able to get that screw to seat perfectly flush (not 'crooked') with the way you have your axle inserted. By the looks of it in your photo, the axle tread in on the non-drive side at the moment. I would suggest that is the wrong way around. That could attribute to more forces being exerted on that side's receiver than what it's designed for. The carbon on that side also doesn't have any other features to assist with those forces (as oppose to the hanger bevel on the other side). Swapping it over might just get the screw flush, but you can still expect the screw to drift in the hole and not be centered in the receiver.

Also, typically these binding screws are further way from the axle center. So it may also be an effort to compact the design as well.

Pretty gif for clarification:


After fall bicycle feels really slippery

For the most part, whenever the front wheel on a bike skids or slides at speed, the rider wipes out. The only people that manage to stay up right are either very lucky or have reflexes that Jedi warriors would be envious of.

If you are riding after a recent fall and feel like your front wheel is sliding, but you are still upright, then you have some sort of post-crash confidence hit, and are interpreting any motion as being an imminent crash.

Check that your fork isn't damaged, handlebars are aligned, and that your wheels are true, but otherwise just keep riding and rebuild your confidence.


Most bike screws are 4, 5, or 6 mm allen bolts. Any bike shop will also have these in stock. You could probably hunt up some stuff in your local hardware store, just bring your bike along.

On the net:

Loose Screws bicycle small parts
Planet Bike does free shipping on small parts (scroll down a bit to rack hardware and such)


Properly tensioning a belt drive with two tensioner

To try and get the wheel perfectly straight you could try to fully loosen each nut on each tightener. Then put each nut back on its respective tensioner and whilst tightening count the number of turn on each side.

Make sure there are an equal number of turns on both sides. I usually do this by tightening one side first whilst counting number of turns, then tighten the other side. Make sure the nuts/quick release with which you tighten the wheel are not loosened too much, if they are the chain tension might increase quite significantly when tightening the wheel nuts/ the quick release (because in some cases the frame bends inwards resulting in a somewhat different chain stay angle which causes the extra tension).

Usually if the chain (not sure if this is the same for belt drive but it should be ) tension is too high you will feel the 'steps' in the wheel /freewheel/casette bearing when turning the pedals by hand (you will feel little bumps every so often whilst rotating the pedals by hand. This could also indicate somewhat worn bearings but chain tension definitely plays a role in it as well.

Another sign of the tension being too high:
Spin the pedals to make the rear wheel rotate (whilst the wheel is off the ground), release pedals and see if they stop turning immediately or if they continue to rotate with the back wheel (I am assuming you have a freewheel and are not using a fixed gear), if they do keep turning this can be caused by chain tension being too high (or bad bearings),  this could potentially also indicate misalignment of belt relative to rear cog (wheel not aligned with frame) so if your bearings are in good condition and chain tension is good the wheel might be misaligned.

Try loosening the belt a bit and see if it helps (if aligning the wheel didn't help, as long as the belt doesn't slip/run off the cogsyou shouldn't need you could also measure the 'stickout' of the threads of each tensioner using a caliperor other measuring tool and compare both sides and make sure they are (approximately) equal to try and align the wheel.


Intrepid twenty on speed, getting information and understanding the gears?

okey so if you have to keep the chain preaty straight to keep the chain live healy.So  from what i was told, if you ride with the smalest gear on the front on the back you have to use the bigest the second bigers and the tird biges. if you use the midle gear on the front on the back you can use the 4th bigest,5th bigest. and if you tide on the front the bigest gear you can use the 6th bigest and the last one with in you case is 7th (that was what i was told if its wrong im sorry).


When I pull my disc brake handle the mechanical caliper will grab then release

On mechanical disk brakes it is pretty common that the caliper is broken: the spring inside it just slipping when enough power applied (yet this power not enough to brake).
It is easy to check it: push the brake lever and look what is released there: the cable from the nut, or the caliper itself jumps back.
Probably you should replace the caliper.
New calipers coming with new pads, so it's a good time to clean up the disk with a good degreaser and maybe a sandpaper to save the new pads from all its garbage.


I find that I'm always in my highest gear. What options to I have to re-distribute the ratios to a more useful range

To get higher gearing, you'll need either a chainring (front gear) with more teeth or a sprocket with fewer teeth. Mountain bikes usually have smaller chainrings because off-road speeds are generally slower. For example, a mountain bike with a triple crankset with 24, 34, and 42-teeth chainrings would be limited in its top speed by the largest (42-teeth) chainring. In constrast, the largest chainring on a road bike may have 50 or 53 teeth, giving 19% or 26% higher gearing respectively.

Unfortunately, upgrading probably won't be as cheap or easy as you hope. You can't just replace a single chainring, so you would need to get a whole new crankset (the crank arm plus chainrings) and also a new front derailleur. Depending on how much your bike is worth, it may be better to get a new bike.


To build endurance, ride farther. Do repeats on hills. Shift to maintain a more or less steady cadence as you climb.


There are bearing races on either side of the hub, and in my experience there is not nearly as much space between the bearings as your picture shows. Having replaced several axles in older hubs, it always seems as soon as you pull the axle out the bearings fall into the inner space of the hub.

The two bearings you can see are likely from this kind of problem. Remove all the bearings, clean and grease the races. Clean the bearings and replace them. Most of the time they are the same size on both sides but you will want to make sure. When you replace them there should only be a little bit of play/space between them. It's normally obvious if you've tried to put too many bearings on one side.


Why does RockShox say you shouldn't use a bolt on axle on their fork?

I came to some assumption why you should not use bolt-on axle.
It is hard to screw the axle preserving fork sliders in one plane. They can get positioned ascrew, because of screwing the nuts in the opposite directions. It is not a problem in motorcycle suspension because of lack of fork brace. But here? let's say you sit in front of your front wheel and have two wrenches, one on each nut. When you tighten left-hand nut, left slider is pulled back by the nut and when at the same time you tighten the right slider, it is pulled forward. Fork brace prevent sliders from returning to initial, single-plane position. This result in suspension that does not move freely, because more tension is put on "fore-surface" of left stanchion.

This "ascrewing" is easy to observe when you're mounting an old fashioned mudguard with mudguard stays mounted on the axle.

I'm sure, that you are able to use bolt-on axle and screw it properly (by using proper nut and spacer and by greasing spacer - nut interspace). Keep in mind, that user/service manual has to be idiot-proof.


Is it possible to commute 34 km (21 miles) daily?

That's similar to my old commute (a bit further but flatter), and I didn't cycle regularly when I started. The Google estimate is probably reasonable for the second time you do it, though may not reflect rush hour traffic. The first time will probably take longer due to unfamiliarity (a trip when it doesn't matter if you're late is helpful) and eventually you could be noticeably quicker.

You might get away without a shower in winter, if you're prepared to set off cold, but in summer it's another matter. Mild wet days are also sweaty. Is there a shower available?

When I started bike commuting that sort of distance it was quite tough. Having rest days in the first few weeks helped, and I found that a protein bar or flapjack immediately on arrival in the morning made the return leg (and the day in work) easier


what is difference between remote lockout and hydraulic lockout?

Remote as a general term means "controlling from a distance".

From that perspective it can work with either hydraulic or mechanical lockout. It is a separate entity to the lockout and is just a way of controlling it from, say the handlebars.


Rolling backwards while pedaling forward on a Freecoaster

I think there is some confusion about the difference between a Freecoaster hub, a Freewheeling hub, and a Coaster brake hub. So briefly:

A freewheel hub is by far the most abundant and utilized piece of bicycling technology and relies on a ratchet and pawl mechanism (or similar) to engage the drivetrain while pedaling forward, but allows coasting when not pedaling. Any freewheel or cassette hub uses this technology.
A coaster brake is a type of brake that is built into the hub shell that turns backward pedal force into braking force.
A Freecoaster hub uses a clutch mechanism to engage the hub shell while pedaling forward, but disengages the hub while pedaling or coasting backward. This allows you to coast backwards without having to move your pedals. They are totally silent because there are no pawls!

Above is a hastily drawn sketch of a freecoaster hub. There are no pawls...instead is a cone shaped clutch which is threaded onto the driver body which extends over the axle. The driver cog on the left is supported on the axle by bearings on either side (there are also lots of other bits and pieces, but these are the general parts.) When pedaled forward the driver threads through the clutch and pulls it into the wedged surface of the hub. The friction between the hub and the clutch is what drives you forward. When you change directions (or pedal backwards) the driver threads the clutch to a backstop which adjusts the play from freecoasting to pedaling forward.

If you were to pedal forwards while coasting backwards, your pedal force would engage the clutch into the hub shell. -- As @Daniel R Hicks pointed out, this is pretty much the same mechanism that a coaster brake utilizes except in reverse. Pedaling forward ought to engage the clutch and slow you down. --

However...I'm not sure that I recommend that you do this because neither the clutch surface nor the hub shell are designed for slowing, only for engaging. (If anybody has more info on the actual construction of the hub shell...whether there is a steel insert to bear against and provide braking support, or whether the driver and hub shell are forward motion only, please edit away.)

Here is a fantastic video about freecoaster anatomy.


The marginal cost of cycling is extremely low (i.e. the cost for an extra bit of use), especially as kids' lessons are going to be light use (I doubt they're hurtling off kerbs, for example). Kids' bikes are also heavily built in proportion to their riders, who are weak compared to adult riders, while the chain (for example) is unchanged.

Depreciation of bikes has little to do with distance travelled and more to do with age (unaffected by the loan) and apparent condition (e.g. rust - how are they stored? How often are they dropped on painted parts?).

If the bikes are being serviced once a year anyway, that's probably enough for some extra riding, though they may want a safety/basic check after being transported between sites (have the brakes been knocked, is there air in the tyres...?).

Ultimately this is a form of business decision (though I dislike the term in this context). It's highly unlikely for the extra wear to shorten the life of non-consumable parts, so if you covered your consumables costs (with a possible allowance for extra wear) you should be fine. Accident damage is another matter (also theft etc.). I suggest you enquire about insurance but probably choose to self insure.

You should talk to the LBS volunteers to get an idea of whether they think they'll need to do more, and whether they'd be happy to do so on the same terms.

So to actually estimate what it might cost, I'd start from an average consumables cost per bike per year from your records. This is for a month's use, so I'd try to recoup that per month lent out. This is almost certainly more than enough alone as rust and perishing rubber are a function of time, but if the number you get from that seems low in the context of the market (sorry!), a safety factor wouldn't be a bad idea. Obviously if you do end up with (extra) insurance costs you'd factor this in, and you'd gauge interest in advance to know how to share that between renters.


The increased weight of the larger wheel (if indeed it does increase) will of course add weight to the bike, but additional weight adds very little rolling resistance (though it does of course affect hill climbing).

It is a myth that "rotating mass slows you down".  In terms of top speed there's no difference between weight on the wheel rim and weight anywhere else on the bike.  Added weight on the wheel rim does reduce acceleration, but 10 grams on the wheel rim only has the acceleration-limiting effect of 20 grams elsewhere -- it's not really enough to notice.  (And once you've accelerated to speed this effect goes away.)

A larger wheel can ride over slight irregularities in the road with less energy expenditure, and so can be more efficient (and less tiring) in some circumstances.  And a larger wheel generally is more stable (though at the expense of maneuverability).


Can I fit a front rim brake to Vanmoof VM3?

If your bike looks like the stock photo, then possibly.   However you may need new wheels.
There's a bolt that passes through the fork from front to back, just above the mudguard/fender.  This would be where a caliper brake would mount, and the mudguard would be "pinched" under the nut, on the other side of the fork from the brake mech.
You would need a side-pull caliper which has enough "reach" to get out and over the mudguard, and then down to the brake track on your wheel's rim.
This fork would not support a V brake or any other style that bolts onto a pivot below the brake track.  A caliper brake like a tektro R559 would likely reach. (not a product rec, just an example of the style)

You'll also need a brake lever for your handlebars, and an inner cable and length of outer.   I'd suggest looking for a lever that can clamp around your bars without having to undo the fancy leather-like grips.  They may not survive being removed and reinstalled, so a brake lever with a two-part clamp will make it much easier.
However, before you start, look at your front rim and figure out if it has a brake track or not.  The brake track would be silver or possibly black, but would generally be flat and just inward of the tyre.  This is a rim brake track:

I suspect your bike's rims may lack this brake track because it wasn't designed to need one.  If there's no brake track, you need a new rim on your wheel, which may require a new front wheel instead.


They will definitely be lighter, and probably shift a little better. More rigid is possible but not especially likely, as the cheap one will be strong enough to take a lot of abuse (they don't particularly care about weight so that's easy to do).

(edit) A cheap crankset very likely has the chainrings rivetted on, and they're not designed to be changed. Sometimes the smallest chainring is bolted on and can be changed. Swapping one of these for a more expensive one that has interchangeable chainrings will probably give better shifting.

Cheap bikes are the ones more likely to be bought by people who either weigh a lot or are careless with their bikes, so are more likely to be overloaded. More expensive bikes get crashed instead. The cranks are designed accordingly.

As discussed in  Suggestions for progressive upgradation of bike you're almost certainly better off saving up for a more expensive bike rather than trying to upgrade the one you have. Buying parts retail is a lot more expensive than getting them as part of a bike (manufacturers buy 1000's at a time and don't pay for retail packaging).


Need some experienced eyes on removing cog/rear wheel mechanism

The outer ring looks like a lock ring. This should help you get it off:


Will a bicycle trailer damage my (steel) bicycle?

These hitches don't work very well. They don't grab tightly enough, so they can twist around the bar and bump in to the wheel. As they twist they will take off the paint. They also require a lot of turns to attach and remove.

I had two trailers with this kind of hitch, and 3 bikes to pull with. I bought this Burley flex connector for each trailer:

I used this kind of hitch:

It works pretty well, but on one bike it's slippery, so the quick release lever can turn a little even when tight. But not enough that it's going to make the wheel fall out. Also, on one bike it bumps in to the QR, so I have to put it in just the right spot.


Uniglide. Cassette, not freewheel. The small cog is the lockring. Remove with two chainwhips.


If it doesn't happen when you pedal ( and it wasn't like this before you took it to the shop ), it sounds like someone who worked on your bike at the shop managed to displace the plastic cassette guard that sits between the cassette on the spokes, or they somehow negatively affected the rear wheel hub. At any rate it, they didn't reassemble your bike properly. If I were you I would take it back to that shop right quick and make sure they fix it for you for free.


Is it 'safe' to use a 700 x 47c tyre on a rim with inner width of 15mm?

To fit 700c (ISO 622) wheels into a bike built for 27" (ISO 630) you only need to shift the rim brake pads down 4mm. If you're exceptionally lucky your current brakes will have enough reach and you'll just have to adjust the pads. That's the first thing to check, because if that doesn't work there's no way you're going to do this on a $50 budget.

2" wide tyres should be ok on the 700c rims. Not ideal, and probably outside the manufacturers specifications, but it should work. I've done that with 406 wheels before and it's worked pretty well.

The real problem is the tubes. Again, new tubes overstretched like that would work in a pinch, but they're be extra vulnerable to punctures because of the stretch. But usually if you're replacing aged tyres I'd suggest new tubes since they're likely to be in similar condition. Trying to over-stretch old tubes is very likely to fail immediately, and if not will almost certainly fail shortly after you start riding.

If you can get the 700c wheels to work, I'd go with a 38mm tyre rather than 42 or 48, just because I'm really wary of damaging the tubes. I assume on your budget you can't afford to carry a spare. But really, if you're doing a ride of any length I think you should buy at least one spare, unless it's a ride you can bail out of and get someone to carry you and your bike home. Even a cheap, shitty spare tube is better than nothing. personally I would cheap out on the tyres in order to buy a couple of tubes. It's not worth going out on a ride and having to go home because your old tubes give out.

If you can't make the brakes work I suggest buying the fattest 27" tyres that will fit your tubes, which is likely to be 1 3/8". I'm sure I've seen 1 1/2" x 27" tyres but I can't find any now.


Do I need to protect my leather saddle from the sun?

I'd think a white opaque plastic bag over saddle would do fine.  The leather has to breathe - if you wrap it tightly then it might grow mould.
You might have to treat your saddle leather a little more frequently if it lives in the sun/heat a lot.
Ideally, store your bike inside, a garage, or at least under some rain protection.  A balcony/porch/etc is better than out in the weather.   A wall-hook or lift might let you utilise unusable space.


Schwinn AC Plus Performance Carbon Blue spin bike pedal removal

To remove a pedal from a crank arm is merely a matter of unthreading it.

Most pedals use a pair of flat surfaces just outboard of the crank.  A normal adjustable spanner may fit, but the proper tool is a thinner pedal spanner with a width of 15mm

Pedals may also have a hex driver socket on the inboard end of the shaft.  This might be a 6mm, 8mm, or 10mm hole and is driven with an allen key.

Some pedals have both flats and hex hole.

The "Crank Puller" is the wrong tool for the job.  A puller works to remove the crank arm from the bottom bracket, and would look like this:

An auto gear puller is also the wrong tool.  You need to unthread, not pull-off.

Since you've crossed the threads, its likely that the crank arms are damaged.  It is possible the pedal threads are also damaged.   And the amount of damage will increase the further in you got the pedal axles into the cranks.

You need to back out the pedals, clean all four threads, and inspect closely.  It will take a lot of force to undo this, though not as much as it took to get then in.

Next time something takes that much force on your bike, stop and check.  While some actions do require force, threads are not one of them.

As for recovery, you are probably up for new crank arms, and perhaps pedals.

As an alternative, you might be able to retap the threads using the proper sized (and handed) threadding taps.  However if there's not enough meat left in the crank, another alternative is to helicoil the holes.  For this you'll need a pillar drill (not a hand drill!) and the right helicoils, in both handed-orientations.  This is something a quality LBS can do.


For fitness's sake, is it better to ride with low cadence in high gear or higher cadence in medium gear?

In terms of losing weight immediately, the obvious answer is to use whatever gear combo allows you to produce the greatest energy output.  For most people this will likely be a hair lower than the "preferred" range of about 70-90 RPM -- maybe 50-60, and pedaling as hard as you can.

However, if you want to KEEP losing weight by getting on the bike again tomorrow (or even just later this afternoon) then you should avoid muscle and joint injury by running at a higher RPM (70-90) and not being quite so extreme in terms of putting out effort.

And one should consider doing "intervals" of alternating high effort and low effort (eg, 5 minutes high, 10 lower), as studies have shown that this produces both better weight loss and better muscle building.


Your hub looks like a serviceable cup and cone types, so you will be able to fix the problem.

You will have to disassemble the hub, but it is not a difficult procedure. You will need some special tools - a chain whip and cassette lock ring tool to get the cassette off, and possibly a cone wrench.

There are many resources available online that can guide you such as this Park Tool Company article.

You may need to simply adjust the bearings, but you should check the amount of  wear on each bearing component and replace if necessary.


Biking against traffic on a one-way streets in Europe

In Holland, were I assume cycling is much more common than in Poland, the kind of traffic sign you describe are abundant (see example, "uitgezonderd" is Dutch for "except for").

And cycling against traffic in a one-way street without the sign is indeed illegal. The same rules seem to apply in Poland, though I cannot find a reliable source for Polands cycling laws. As to why Google Maps suggests those routes remains a mystery, but it doesn't seem to happen only in Poland, see this link


Fitting Shimano pedals into a 3/4" crank socket

I've never heard of a 3/4" thread on a pedal on a bicycle.  It sounds like they intend for you to buy pedals from the maker of your exercise bike.
However if you are handy, it may be possible to make a pair of adapter bushings from metal.

The pedal threads will be 9/16" with 20 TPI (which is not the more common 18TPI)   Sadly 20TPI is unique to bicycle pedals, so you're not going to be able to use plumbing parts for this.
One has to be left-hand thread for the left pedal's shaft
And the outside will have to match the 3/4" and whatever thread pitch is in your bike's cranks.  This may be 16 TPI for UNF thread, or 10 TPI for UNC, or something weirder.
Also its not guaranteed that your 3/4" threads are opposite-handed.

Given your bike is Chinese, its probably metric for the most part, so there's a chance your pedals have an M18 or an M20 thread, 3/4" is about 19mm so right in the middle of those options.   None of them are pedal threads I've heard of though.
This would be a simple job for an engineering firm to fab up from a couple of small disks of steel or maybe aluminium.   It would help if you could give them both cranks and both pedals for test-fitting too.

There was a short lived thread of 1 inch, called Shimano Dyna drive.  Adapters from that down to 9/16" look like this.  Notice the inner is completely within the outer, because there's enough metal to make this possible.

The other option is to stagger them a little as in this 9/16 to 1/2 inch adapter set.  Downside of these is they increase your "q-factor" which means your pedals are further apart.

Images are for description of the adaptor required, not a specific product recommendation.  Pictured products have the wrong threads for OP's need.


How much does a typical cardboard bike box weigh?

First, I'll give you an estimate on the weight of a cardboard box. Then, you can read the side notes at the end of this answer to see why the weight is a relatively irrelevant quantity.

EDIT: This link sells a bike box and lists the weight as 7.40 lbs. The rest of this answer gives you a way to estimate this, as well as tells you why this whole problem is irrelevant from a cost perspective.

According to this link, the density of cardboard is approximately 30-90 kg/m^3 or 0.03-0.09 grams per cubic centimeter.

Now, lets estimate the amount of cardboard in a box. Say each side of the box has thickness T centimeters, and the sides of the box are L,W,H in centimeters. Then, the volume of the cardboard in the box is 2*T*(L*W+L*H+W*H), so the mass of cardboard in the box is density*volume of cardboard or between 0.03*2*T*(L*W+L*H+W*H) and 0.09*2*T*(L*W+L*H+W*H) grams.

Now, lets estimate the dimensions of a box to ship a bike. According to this thread, the typical bike box is about L=130 cm long, W=18 cm wide and H=79 cm height. For thickness, to make the numbers a bit easy, lets say the cardboard is T=1 cm thick (this is significantly thicker than most bike boxes I've seen).

Plugging into the formula, we get a range of approximately 800-2500 grams for the box (1.75 to 5.5 pounds).

I suspect the thickness of the box is closer to half a centimeter (which would halve the estimate) and the density is probably on the higher end of the scale (but probably not 0.09 grams/cm^3). So, I'd guess the weight is closer to 3 pounds.

The simple solution is to take a scale, and a bike box and weigh it.

Side note 1: The dimensions from that thread are only slightly different from your box, and the values come out to be nearly the same.

Side note 2: With carriers like UPS and Fedex, the expense of a shipping bicycle is not primarily the weight, but the fact that a bike box has large dimensions, so it can count as an oversized package [and paying the LBS to pack it]. For small packages of the same weight, note that the cost of shipping will be significantly lower (go to the UPS shipping calculator and put in your source and destination with a small box, say, 10 in x 10 in x 10 in weighing 50 pounds versus a bike box weighing 50 pounds). UPS calls this dimensional weight, so for your bike box, it will charge you assuming that your package weighs ~75 pounds even if your bike weighs 10 pounds packed. So, I guess you can fill your bike box with some rocks or something cause you're paying for 75 pounds even if you don't use it anyway!


Have replaced v-brakes and they still squeak. What to do?

Is there a chance the rim is wearing out? Have you tried a different wheel? Have you tried toeing the brakes in the opposite direction? It sounds like you've tried just about everything else. I'm leaning towards the wheel being the issue. Otherwise it sounds like the frame is just prone to resonance with the vibration of the brakes. I've got a mtb frame that doest this horribly with the back brake. Several friends have the same frame with different brakes but the same issue. Some frames are just more likely to resonate than others, though it's usually more of a wheel issue with rim brakes.


Ultegra 6800 shifter with R8000 rear derailleur?

Should be OK. Both shifter and derailleur are 11 speed, only 1 generation apart. AFAIK Shimano did not change the cable pull or derailleur movement ratio.

All the other derailleur specs check out:

As you say, the R8000-GS goes up to a 34 tooth max sprocket.

Your front ring tooth difference (10) is within R8000-GS max of 16

Your total capacity required (34-11 + 44-34 =  33) is well within max of 39.


Should I choose 26" or 28" size BTWIN Triban 100 with dropped handlebar?

Vertical height is easier to adjust than 'reach' or the horizontal distance from the handle bar. Check which one is more comfortable there. I would err on the smaller size myself, as long as it isn't too small, since the reach being even slightly longer causes neck and other pains.


For grades beyond 10% having a gear that you can spin at the rate you can climb makes a big difference.

Only you can know exactly what gear that should be. If you can find a gear ratio tool that displays speeds for a given gear, wheel size and rpm. This one seems pretty good.

http://www.bikecalc.com/cadence_at_speed

Then think about your typical speeds while climbing on the steep sections. You need a gear that will allow you to spin at a least 60 rpm and still keep those speeds.

A gear that works at 30% and 60 rpm probably isn't possible with a compact crankset.

FWIW, Where I ride has lots of climbs above 10% in the 5-10k range and I see lot's of riders with compact cranksets and 11-34 clusters.

Personally, I think if you are really considering this, you'd be much better off getting a compact 110 Bcd triple and something like 24/36/48 gearing. It's not that you get that much lower gears, but you get many more useable gears. Having a choice of a few gears in the low range makes a lot of difference compared to just the one or two extra low gears you get by going to a wide range cluster.


If you don't want to use a bicycle grease (Park Tool PolyLube 1000 or Phil Wood Waterproof grease or Shimano's greases or whatever), use something like automotive multipurpose or wheel bearing grease.

The Valvoline stuff is red and comes in a big tub for about 5-10 dollars and can be bought at any automotive shop.


What kind of paint should I use on my plastic mudguards?

My first step would be to scuff the surface with a Scotch Brite pad. You want some minor surface imperfections for the paint to adhere to. Clean the surface with either alcohol or what the instructions for the particular paint call for. I am partial to automotive brake cleaner. If you can get it, use Rustoleum Spray specifically for plastic. Apply two coats of primer. Allow it to dry between coats. Then apply two color coats. You have to use a paint intended for plastic because conventional paint will not flex without cracking or chipping . As @Daniel R Hicks has stated, allow the paint to fully cure before it experiences any contacts. If you can set it in the sun for a couple of days it should excelerate the hardening. Even doing this the paint may chip if the fender experiences severe flexing.


Should I apply pressure on the saddle during downhill on a rigid frame

No. If you sit on the saddle then you become connected with the bike. That means that the next hit from the ground will be transmitted as is on you and you'll most probably go flying in an uncontrolled manner, usually nose heavy, and you don't want that.

Apart from getting rest or pedaling, the only case where you touch the saddle is with your inner thigh (one, not both of them) in some offcamber cornering scenarios. But I think this is irrelevant to your question.

General rule for descending on rough terrain is:

heels down, applying max pressure on pedals (that's for flat pedals)
body in attack position
hands relaxed, ready to act as suspension
knees relaxed, ready to act as suspension
stay low
look ahead, not down to your front wheel


Can a 26 Inch Controller Drive a 20 Inch Wheel?

You may be able to reprogram the wheel size controller from the lcd control panel (or usb reprogramming cable). But this assumes a certain level of intelligence in the controller and yours might not have this capacity. You’d have to check with the vendor.

Even if it were reprogrammable you have the following challenges:

Motors have optimum torque and speed ranges. Your motor may be wound for slower rotations of a 26” wheel and won’t give you enough speed that a 20” needs
controllers may obey the ebike assist speed limit by limiting max RPMs. If your controller isn’t wheel size reprogrammable you’ll find yourself limited to a much reduced speed  and even if you can, the physical/electronic max rpm limit may still limit your top speed (my Bafang geared hub motor/controller doesn’t seem to go above a certain rpm irregardless of the wheel size; this may be either a motor or controller limitation)
you’ll need to build the wheel and you might find some of the spoke angles are going to be very tight
a rear ehub will not fit normally in the front forks because of the hubspacing and freewheel clearance.