This is most likely because you are putting your weight right on the median nerve (see first picture).  Padded gloves may help a bit, but I suspect your hand position is more likely to be the problem.

Other common hand nerve problems with riding can compression of the ulnar nerve, which will present itself as a different area of sensation than what you are experiencing (second picture)

If you are using road bars

I remember you were riding a road bike in the Legs are very weak question.

Next time you ride, watch how you place your hands on the handle bars. If you are using road bars, beginners often place their hands right on the bend between the Tops and the Ramps (see second picture).  This would put pressure directly on the median nerve.  Try riding on the tops, ramps, hooks, and drops instead of the bend between the tops and ramps. It is also good to rotate through the four hand positions rather than using  just one position.  You may also find that adjusting your cockpit dimensions can make some of all these positions more accessible and comfortable.


Mech disc brakes creating too much slack

Your actual rear brake looks like a electric scooter brake, I would ask whoever you got this bike from if they done any mods or maintenance on it.

1st Image

Unfortunately I don't think any form of adjustment will get you any sufficient braking.

2nd Image

You can see from the second image the different cable route designed for use on a bike, generally the cable is fairly straight from the nipple to the clamp.

My suggestion is first find out if the brakes were replaced, and secondly if they were replaced which I suspect they're, you need to get the correct brakes installed for efficient and safe braking.

Artek Vigourous brake sets can be bought for £25 a set front and rear.


Since I switched to my 29-er in september, I can keep up with the fastest bikers in my "team". Before that I just could not. It could be due to the new material, but I think there's a speed difference of about 2 km/h.

I bike on the flat tracks of nothern Belgium and the south of the Netherlands. So no climbing or descending.

The 29-er is definitly faster on (loose) sand, and mud. And a lot more comfortable on tree-roots and the "Belgian Blocks".

For really, really small turns, I notice the wheelbase is larger, but otherwise I do not notice any difference in handling.


You usually can only lace a leather saddle when it becomes sunken in the middle. Lacing the bottom across underneath will tighten up the sagging middle. This wouldn't likely be a "do it yourself" project without the proper tools/equipment. From your description, it sounds as if you're sitting on the saddle off to one side. I'm not sure this could be corrected by lacing. If you've had the Brooks saddle less than two years, then it should be covered under warranty if there is a problem with the leather itself or the seat frame construction that allowed this to happen. You'd need your receipt and return it to the dealer where you purchased it. It the saddle isn't under warranty, I'd suggest you take it to a horse tack shop in the area and see if they could straighten it up, reinforce the bottom and punch holes at a proper spacing to lace it up for you. Here's a link about the Brooks warranty, just in case.

http://www.brooksengland.com/getting-in-touch/contact-forms/info-request/warranty-claim/


What is the proper way to cut brake cable housing?

There is a proper tool that is probably the best solution. They cut so that it does not smash the ends or the metal inside of the housing. Many also have an awl in order to help reform the end if any smashing or deformation does occur.

Most look something like this:

It is also possible with a brand new razor blade but the proper plier like tool makes it a lot more quick and easy.

For hydraulic hoses they differ slightly because of the difference in hose material, there are two type of hydraulic hose cutters, one that looks a bit like a pill cutter such as this:

Or the handheld variety that function quite similar that looks like this:


Why do peope think the upright postion is comfortable?

In general terms, a more forward position will mean that more body weight is supported by the arms, and that the back/spine is rotated forwards to a greater angle. The neck will also need to support the weight of the head at a more strenuous angle.

This will put more stress through joints in all of these areas and lead to faster fatigue of the supportive muscles, some people will find this less comfortable if they aren’t used to it.

Perhaps you have grown accustomed to your position because it’s how you’ve always ridden. Maybe your arms are used to supporting your body weight for example. This conditioning means you can be comfortable in a forward position for longer than average.

Riding out of your normal position probably means certain muscles have to work in unusual ways to support your body weight in a new position and they just aren’t used to it, so for you it is less comfortable.

Meanwhile, there will be other riders don’t have the same conditioning and experience things the other way around.


Phil Wood Hubs rarely have issues. If it is the pawls that are the problem, a rebuild kit will be enough. They are replaceable parts. They are the "teeth" that the freehub use to drive the hub shell (and the rest of your wheel) forward.

Let them try a rebuild. You won't lose anything by it, and it will be faster than an RMA. But if you continue to have issues after, then warranty the hub.


How should I measure my 60 second resting heart rate?

The usual recommendation is to just pedal slowly and then take the measurement. If your recovery rate is 12BPM or less, you should go see a doctor. A very fit person would recover 40+BPM. Someone who engages in regular cardio exercise would probably see recovery rates of 20+.

This is a HRM function that I use only a few times a year; like when I get back to real rides in the spring. It's probably most useful for either someone in training or a person starting out on a cardiovascular fitness program.

There's a chart on the wiki answers link.

http://wiki.answers.com/Q/What_is_a_good_Recovery_heart_rate_level

And another:
http://www.drmirkin.com/heart/8076.html


Rear wheel touch frame during off saddle sprint

Possible causes may include:

a. The tyres are too wide for the frame, check the clearance between the tyre and the stay. Be aware that there are dynamic shape changes under load.

b. The wheel is too soft. Does it suit your weight? Are the spokes properly tensioned, even though the wheel is true?

c. The rear triangle and/or the bottom bracket housing are too soft and move sideways. This is the case on certain frames. It happens with powerful riders who may put a high load on pedals especially off saddle. You research on cycling magazine sites who tested the bike. To check the sideways flex: Stand over the bike, put the left foot on the pedal, lean the top tube against the right leg, pull both brakes and push the foot down hard. You'l see how far the BB moves to the right.

d. The wheel axle has play. You can check this if you lift the rear wheel or, better, put the bike on a stand and try to wiggle the wheel sideways.

I'd say that the most likely cause is 'c', combined maybe with 'a'.

[edited]


Are cycling shoes comfortable as everyday wear?

Unless you're using clipless pedals, you really don't need much in terms of special shoes for cycling.  However, there are plenty of advantages to using clipless pedals,  so many people choose to use them.

The big categories of clipless shoes are:
Road shoes tend to have the cleat exposed and you walk on it any time you step. This is really bad for regular wear off the bike. These shoes are meant to be lite and used on the bike.

Mountain Bike Shoes tend to allow you to walk around a bit.  Some models resemble athletic shoes and some are more firm and the stiff soles make it hard to walk normally. However, you can usually get buy walking a bit in these.  I wouldn't want to wear them for extended periods of time off the bike if possible.

Urban Shoes (like Chrome and DZR) tend to look like sneakers and feel a lot more like regular shoes.  They still contain a cleat mount, but these shoes are designed to blend in like normal shoes and walk a bit better than most other cycling shoes.  I've worn Chrome and DZR shoes with SPD cleats around all day and didn't really notice much.  The soles are still stiff, so they are a bit different feeling than wakling around in regular shoes.

If you pick up a pair of clipless shoes, you'll still probably want to swap them out for regular shoes at the office if you're going to be there for a few hours or more.  Regular shoes are going to be more comfortable and your cycling shoes might be a bit sweaty.

If you're not planning to pick up clipless shoes, then look for a pair of athletic shoes that doesn't have a lot of flex in the sole when you try to bend the toe downward. A flatter type of tread on the bottom of the shoe will probably help keep you from sliding on the pedals as much too.  Skateboard shoes and Adidas Sambas are generally pretty good choices, but pick what works for you.

If your commute is short, you can always try your regular office shoes. They may not be 'optimal' for cycling, but you don't always have to have specialized gear to ride a bike. Do what works and what you're comfortable with.


Angle grinder is the preferred tool of bike thieves.


Are there any community bike shops in the Netherlands?

I don't know any community bike shops in the Netherlands, never really heard it this although I understand what you mean.

What you will find, is a Repair Café. It's a place where people get together helping each other repair their stuff. Often there's tools of all kinds and you can usually bring a bike too. It has a big community aspect; you can use each others knowledge or tools and repair together.

You can find them on repaircafe.nl. There you have a Google Map which, although the website is in Dutch, you'll be able to use. There is more than 5 cafés in central Amsterdam. Click the link in the pin-popup and you'll get more info and opening times. (There is an English version of their website, but it doesn't contain more than some about.)

I think it is almost the same as a community bike shop. Except that a repair café usually has a short moment of coming together (you'll find meeting moments on the website) we as the shop will be open almost all business hours.


Crank power meter incompatible with my bottom bracket

There’s no kind of adapter to fit the power meter crank to a square taper spindle, it seems to be a Hollowtech II left crank power meter (Shimano 105?). You’d need a crankset with the same Hollowtech II interface. You’ll need to check the width of the Bottom Bracket (B.B.) shell on the bike frame to see if a road crankset will fit.

Also note the gearing may change, with a road crankset, I think the spec says it’s a nine speed triple which you would want to match the best you can, probably Shimano Sora IF you have a road B.B. shell (68mm).

If you want to replace the crankset you’ll need to swap the bottom bracket too, which is no great obstacle, but might require tools you don’t have. Will also depend on the B.B. shell width.

Economics are up to you, you can add up the cost of the new crankset and bottom bracket plus tools or labour, and compare that to the cost of selling it and buying pedals.

I can foresee a case for the pedals, certainly it could be mechanically simpler to install pedals. You’ll have to see if it’s cheaper where in the world you live


Removing lubricant from the rear brake and rim?

Clean them.  I'd avoid using any sort of solvent, as it would be bad for the pads and might simply make things worse.

First undo the noodle so you can access the face of the pads, then wipe pads and rims thoroughly.  Scrub pads and rims with a dab of detergent on a rag, then hose down to remove the detergent.  Reattach noodle.  (I always forget that part.)

The brakes will likely still be a bit "slippery", but riding with the brakes partially engaged for a minute or two should bring things back to normal.


Why do front and rear wheel hubs have different sized ball bearings?

First of all, the standard shimano cup and cone bearing size is not necessary, take their own XTR FH-M975, this had 3/16th bearings in a rear hub.

One thing I considered just now was that an MTB will sometimes be on only one of the hubs, so it is unlikely that there are issues to do with damaging either bearing size in this way.

What is left is the typical average load distribution; bearing size and load are both factors in bearing life, as such my overall conclusion is actually that this is a bearing life issue more than anything else, they're simply attempting to obtain the same life from the front and rear. Even as bearings improve this provides a valid reason to keep the size disparity to increase rear bearing life.

http://www.skf.com/us/products/bearings-units-housings/principles/bearing-selection-process/bearing-size/size-selection-based-on-rating-life/index.html

Outside of cup and cone one can take the Hope Pro2 Evo for example, the front takes 20x32x7 while the rear takes 17x30x7, the bearings in both are the same size, but the rear has less of them. I'm guessing that the front only takes more bearings to increase the cartridge radius to accomodate larger axel standards. It's worth noting there are another 3 bearings in the freewheel of the hub, I'm unsure how this affects things, but then there are also bearings in the shimano freehub. Edit: Anecdotally the rear bearings on my pro2 evo needed replacing sooner than the front.

The load really is significantly different:

Lennard Zinn on measuring rear and front load, and "don't be surprised if it's 70/30"

http://www.velonews.com/2015/01/bikes-and-tech/technical-faq/technical-faq-weight-distribution-compatibility_357312

For otherwise identical bearings the load it can take increases with size.

https://www.bearingworks.com/bearing-sizes/

The above is not ideal as it deals with 6000 series cartridge bearings, where the number of bearings varies as well as their size, but it shows clearly that the the load rating increases with size of bearing (when the width increases).

If you want to get more in depth with regard to anything and everything bearing related then check out and explore starting from

http://www.skf.com/us/products/bearings-units-housings/principles/bearing-selection-process/bearing-size/index.html

http://www.nmbtc.com/bearings/engineering/load-life/

EDIT:
My final thought is that cup and cone are the staple of cheap hubs, any change would presumably increase costs (at least initially) and go against standard expectations for bearing sizes, any increase in cost to a manufacturer is passed on to the consumer, in the case of budget hubs there's really no advantage to the consumer for the increased cost, I mean, they work, they work very well for a very long time when maintained, and surprisingly well for surprisingly long even when they're not! Even if you could show this or that improvement in weight or rolling in an optimised hub, would this actually translate to more profit? I doubt it very much. So manufactures just keep things the way they've been, because there's no advantage to be had for the company by changing it.

Also consider the complaints from people that you messed with bearing sizes, no doubt there will be enough people who will put the wrong bearings into the new hub, who will then proceed complain that your company sucks! There are countless examples of technically sub-optimal solutions everywhere you look, many of them are however optimal for profits.

I strongly believe (but can't prove) that a simple philosophy that "both wheels should last equally long" was the main driving force behind the initial decision.


short cranks for new Brompton JIS bottom bracket

It seems to be fairly straightforward, I found a number of links around the web to people who have done it. Any crankset can take a single chainring, just make sure you mount it on the correct side of the spider when you do the swap. Try to match the existing chainline.

You may need to change the bottom bracket to maintain chainline and crank-frame clearance, but none of those links mentioned it as a problem.

FWIW I'm 180cm tall and run 150mm cranks on my commuter because they were the shorted I could get without paying silly money. They were the same price as cheap standard cranks. Unfortunately they're also made of low-quality aluminium and have bent somewhat in use. If you're strong or heavy I suspect the same may happen to you, but a Brompton is sufficiently flimsy that it may not be an issue (you might not be able to apply enough force without breaking the bike). IMO the best solution is to wait until it happens and buy more expensive cranks then, rather than paying up front when you might not need to.


Replace threadless headset retained bearings with sealed bearings?

Yes, it is possible. The headset compatibility is determined by steerer tube and head tube dimensions. The type of bearings inside does not really matter, and the difficulty of getting spare parts for sealed bearings or maintaining loose ball bearings are both exaggerated.

When replacing the headset, check the condition of the frame: if the creaking is because of deformed head tube, a new headset will not help.


Shimano roller brakes: differences between each model and interchangeability

For all I know the roller brake mounting mechanism is the same for all the Shimano roller brake models and all use the same cable pull ratio.

Different (ly priced) models have different stopping power adn cooling (although none are recommended for long braking on descends etc).

Cleaning and regreasing them usually helps. Shimano roller brake grease works fine in my experience, although I suppose (haven't tested) that molybdenum disulfide grease from a store should work fine (NLGI 1 hardness seems apropriate).

Made a video showing how to dissassemble, clean and reassemble a roller brake (lubing is not shown).

There's also a long and detailed explanation of the Shimano roller brakes on Sheldon Brown website.


Hydration rucksacks on and off the bike?

You don't say how long your rides are or how much water is needed per hour.  Going by my personal experience, you'll want 1 bike bottle (also known as a bidon) per hour in neutral/comfortable temperatures, and more if it gets hot.

I did a 12 hour ride and ended up sucking down 8-9 litres of water over the period (a bottle and a 2 litre pack, filled up three times) and that is consistent with a bottle an hour.

Locations: You can have two bottles inside the main frame triangle. a couple on the bars in holders, and two more aft of your seat.  You can also put stuff in panniers or on a bike rack on the back.

Bottles are available in up to ~800 mL sizes too - don't bother with the little ones.   Don't bother with insulated ones either - they plain don't work at keeping the water cool.  Instead you can add ice cubes to both bottles add the hydration bladder before topping it off with water.

Liquid - hydration bladders are terribly hard to clean and dry, but if you don't they will go mouldy.   Only put water in a water bladder, as per the instructions.  Anything with sugar should not be in the hydration bladder.

If you want to carry electrolyte drinks, use a normal water bottle for them.   I've tried them but they taint the plastic, so I can still faintly taste the electrolyte powder flavour several rides later.

I tried using the hydration pack on my MTB frame, but there was a long way to lift the water up the hose to drink it.  I found the pack to be good on the back, and because it was 2/3 ice helped keep me cool for the first few hours of my trip.


It seems like the first question to answer here is: freewheel vs. cassette. The, assumed, age of the wheel and being a 6-speed does suggest that it's a freewheel. However, even if it is an original wheel from the late '70s it is not out of the question that it could be a cassette (at least according to Wikipedia).

Looking at the parts, I see several clues that make me think cassette:

The three rivets visible in the second and later photos.
The nine splines around the outside of the freewheel/cassette body.

Sheldon Brown has a page called Freewheel or Cassette that may help. The biggest differentiator that he mentions is that:

On freewheels the extractor splines do not move when it is spun backwards, but
On cassettes the lockring splines do turn when it is spun backwards.

He also mentions that many cassette hubs have a distinctive bulge, like the one on the image below, on the cassette side of the hub. Sheldon says that if it is there you almost certainly have a freehub, but that the absence of a bulge is not a definitive sign of a freewheel.

Once you know what you've got you'll know if the the strategy is to unthread the freewheel body or to find a way to loosen and lift off the cassette. It is possible that the cassette has worn into the freehub body, like this image from Sheldon:

and will need some fiddling to remove. This article and video may help.


Would like to custom-build a bike but I'm not sure on what parts to buy

Upgrading parts is likely to be the most expensive way to get the bike you want. Depending where you are, second hand is the way to get a good bike for the lowest $$$, provided you are careful. The next least expensive option is to go for an end of season new bike. In the end, it costs a lot less if you use the proceeds from selling your old bike rather than upgrading it.

29'ers  (I have one), give quite a different ride to a 26. Try one out to see if you like it, however if you stay hardtail, I think it's a good way to go. If you are a heavy 6'6, consider the 29'r has longer spokes and the wheels are therefore weaker than a 26 (all else the same). As I am under 70kg (150lb), its not something I have to worry about. Also think about the shock - is it stiff enough for your weight, although the only thing that makes a significant difference at this level of bike is more money, and unless you are over 250lb you should be OK (Trek states 136kg max fro their bikes).

The Mamba looks like a reasonable fit for you in terms of budget and the riding you propose - it will hold up with OK quality parts, I imagine a bit heavier than ideal, but it won't be a dog either. Trek make good bikes and have a good reputation (where I live) for support - which is important.


Is it possible to use custom maps on Sigma ROX 12?

Looking through the specs of the ROX12 it should be possible to store custom map data on a compatible SD card.

The device itself seems to use OSM format, this is Open Street Format that can be downloaded from either
Open Street Map

Or

More Open Street Map Info

According to the manual ROX12 User Manual you should be able to select custom maps from within the device. You will however need a PC of some sort to download the maps and place them on the SD Card, also note the maximum SD Card is 128GB so you want your custom maps being to big.
The advantage of using the first Open Street Map website i linked to is you can pretty much pick any size map, if it gives you an error of maximum export size exceeded you can easily make the map smaller just by dragging your mouse over the page.

Hopefully this helps the OP achieve what they need.


Getting the hub logo facing the valve hole?

Place a single leading spoke and a single trailing spoke- both on the same side of the hub- to get your placement correct. That way you only have to unthread two spokes if you're off. Once you've got it right, unthread the leading spoke if you're planning on lacing trailing first or vice versa and proceed as normal with lacing.


SRAM Rival front derailleur throws chain to the outside, even after professional adjustment

A few things to check:

Check the derailleur height to the outer chain ring. Basically, this should be as close as possible without hitting the chainring.  Make sure it's well secured to the frame.
When you adjust the travel, put the bike into the large chainring, small cog and make sure there's no more than about a 1mm of distance between the outer edge of the chain and outside plate of the derailleur.
Make sure you don't have a bent a tooth on your chain ring.

The only time I've had a chain go over the top of the outer chain ring is when the limit isn't properly set or the outer cage isn't more or less parallel to the chain ring. Remember, to get the derailleur over and outside of the chainring, there has to be enough clearance for the chain to make it.


Giant TCR SLR2 2015 vs Giant Defy Composite 2 2013

As a general answer to this kind of question, I recommend that you buy from your local bike shop. While shops can vary, if they seem to provide reasonable service and the price is reasonable, it's worth buying from them for several reasons

the profit on your sale will help them stay in business - so they will be there when you need service.
many shops bundle clothing, shoes, helmet, bottles, lights, and such with the sale - so you end up with a better deal.
many shops will give you a free service and free adjustments - if you bought from them.

Since there will come a time when you need them, start the relationship now.


Rear Derailleur wire sags completely in higher gears

What you describe suggests friction in the rear housing loop. It fits with the problem getting progressively worse, and with the apparently slack cable, presumably along the downtube or chainstay. This can happen from corrosion, contamination, kinks in the cable/housing, or the housing or cable fraying or coming apart.
It might need new cable and housing. That is normal maintenance and not a big deal if so.
Put the shifter in 7 and leave it there. Pedal with one hand while pushing the derailler inward up to the big cog with the other. Use the slack you've created in the cable to slip the rear loop out of its stop. Try to slip it up and down the cable to inspect for friction. Inspect it for the above. If it's dirty or corroded, get it clean. Put a few drops of oil along it. Shove the derailleur inward again as you reseat the housing in the stop. See if there's any improvement. It would be normal to need to readjust the tension at this point.
If the bike has a housing segment near the seat cluster, it could also be the source of the problem.


How to determine tire size when the sidewall label is unreadable?

Tire sizes are extremely complicated because there are so many different measurement standards. See: http://www.sheldonbrown.com/tire-sizing.html

One strategy will be for you to ascertain what the common tire size of your bike is (more likely than not 700c for a hybrid bike of the 1990s) and order that (I’m assuming you’re ordering online) but that won’t work if someone replaced the rims or wheels on your bike and returning tires would be a pain.

Really, the easiest is to take one of the wheels to a local bike shop (not a bike department in a big box store) and ask them. They can also help you get white wall tires if you want the classic look. If you’re cheap, just get the one wheel done and order the companion online but I’ve found my LBS to be within $5-10 of online prices and it’s worth the convenience. Note: you’ll also need a new inner tube and you’ll likely also need some new rim tape. The bike shop can also ascertain how much corrosion there is and whether or not it’ll affect the new tire.

Note that many older bikes from the 1970s and prior have steel rims which have lousy braking performance.


Disc brakes squeak on Trek mountain bike

The easy thing to check is whether the pads have got a little damp while you weren't riding it. The solution there is to ride it a bit. If the noise bothers you try riding with the brake slightly on to heat it up.

Unfortunately that conflicts with the other problem: if there's oil on the rotor you should clean it immediately and avoid using the brake until you can clean it (to avoid getting oil in the pads because they're hard to clean). Wipe the rotor with either disk cleaner or rubbing alcohol and a clean cloth. Keep doing that with new solvent and new cloth until no further dirt comes off the rotor. Then take a quick test ride, using the brake. Ideally pedal hard with the brake on, so you heat the pads and rotor (and also get an idea of whether the brake works). Remember that riding with the brakes on heats up the rotors - be careful touching them immediately afterwards. Wipe the rotor with a clean cloth to remove any pad goop.

If there was no squeal last summer the alignment should be fine. The way to check is to look at the gaps between the pas an rotors. Check from a couple of different angles, the pad should be parallel to the rotor from all angles. If it's not try squeezing the lever - some pads pull slightly off angle when they come off the disk.

If all else fails buy new pads, clean the rotors then install the new pads. Remember that the new pads will need a little running in.


Why should the outside disc brake pad be closer to the rotor than the inside one?

SRAM's brake setup instructions for BB7 brakes (select user manual from the service documents, step 10 in the user manual) specify that the inboard/fixed pad should be further from the rotor than the outboard/moving pad. The ParkTool instructions that @jimirings links in their comment are specific to this model of brake and repeat the manufacturers instructions in this regard.
Other manufacturers provide different advice, for example Tektro's instructions for their mechanical disk brakes (TRP Online Resources - select "All Spyre and Spyke models" from the road disc subheading under the user manuals section, Tektro Mechanical Disk Brake Owner's Manual, or Tektro Support > Download - select "Mechanical Disk Brake - User Guide") specify that the brake pads should be evenly spaced on both sides of the rotor. The Montague blog you've linked to use a Tektro Novella brake but repeat the instructions given by SRAM, not what Tektro recommend.
Neither manufacturer give any reason for the specific alignment, the only reference I could find was the following section from CX Magazine's article How to: Set Up & Adjust Mechanical Disk Brakes:

Now look through the caliper. The rotor should be sitting center in the gap or slightly to the outboard side. This should position the inboard pad into the gap.
This inboard pad position should be one of your greatest priorities. If the inboard pad is too far out, when you hit the brake, the outboard pad will clamp the rotor against the caliper instead of the brake pad.

The pictures included make it clear that the caliper housing should be slightly offset to ensure that as the fixed inboard pad wears and the rotor flexes it does not contact the caliper housing itself. This would lead to damage to the rotor and/or the caliper.
You should probably still follow the manufacturers recommendations for your given brake model, however aligning the caliper to have more space on the fixed side then aligning the pads evenly would also be suitable if you are unable to find specific instructions from your manufacturer.


Mounting a dynamo headlight to a front rack

Typically, mini front racks have the type of mounts you are looking for. You will also likely need an arm to hold the light otherwise you will have to mount the light upside down, which the B&M is not designed to do.

A number of manufactures sell these type of racks and arms.   The racks will typically have a number of mounting points around the rack, mine happens to have five, two on each side and one in the front (which could use the same mount as the fork crown mount, but this would also expose the light more to knocks and bumps).

In the attached picture my rack is mounted quite low to the tire (so I can attach the fender to the rack), and the light is mounted low below the rack so I can fit a bag on top of the rack without interfering with the light.  As a result the pictured setup gets a slight shadow to one side.  You could mount the rack and light higher which would likely eliminate most if not all the shadow. You could also mount the arm holding the light to the front set of mounts on the rack which would move the light farther forward again eliminating a shadow.  I chose to mount in close to the rack to protect the light at the cost of a slight shadow.

Finally, my fork has an extra set of braze-ons for these types of mini-racks.  There are other types of mounting options so you don't necessarily need this braze-on to use this type of rack (e.g., via p-clamps). Some front pannier racks also have a platform like the one pictured built in, so you can use the regular mid-fork mounting point.


The answer is that yes, a 34t cog and 34t chainring would be the same gear ratio as a 50t cog and 50t chainring. However, the difference would be in drivetrain friction, as this Velonews article demonstrates. Larger cogs and chainrings make the chain articulate less, and these have lower friction than combinations where the chain articulates more. This would be true even if we are considering single-speed or track bikes where the chain is totally straight. Otherwise, the more the chain is angled, the more friction is produced.

Now, would you notice the difference? The testing facility in the Velonews article I linked estimated the the average friction difference between a 2x setup, 53/39 chainrings and 11-34 cassette and the equivalent 1x setup with a 48t chainring was about 3 watts at 250W total input power; 1x systems often have smaller cogs or larger chainrings than the equivalent and optimal 2x gear. The 1x system has the greatest friction in the 48t ring and 10t cog, and this combination has the biggest friction disadvantage to the 2x system's equivalent gear (53x11) at about 6 watts. The next two biggest gears are about a 4-5W deficit to a 2x system. Note that this is all at 250W, and riders operating at lower power would see less of a differential.

Is this difference perceptible or important? In this Cyclingtips review of the Ceramicspeed oversized pulley wheel system, which should be about a 1-2 watt saving, the reviewer claimed he did not consistently perceive a friction difference. In many gears, the 1x system is within 2 watts of the 2x system, so you would be unlikely to notice the difference. In the top 3-4 gears, the 1x system is at a bit more of a disadvantage to the 2x. Nonetheless, the difference even then may not be that noticeable to many riders.

Also, 1x setups lack a front derailleur, which reduces the bicycle’s aerodynamic drag slightly. The Velonews article pegs this at about 3W at 30 miles/hr. This would partially offset the increased drivetrain friction for many users, even those not cycling at 30 mph.

(Edit: note that a previous version of the answer mis-stated the Ceramicspeed system's claimed savings. I remembered that it was 2.4W from somewhere. CS actually claims greater potential savings, but the Cyclingtips article reminds readers that if you are diligent on drivetrain maintenance, you are likely to see only about 1-2W of friction savings from the Ceramicspeed system. If you are not diligent about drivetrain maintenance, then you should be, as it's cheaper than a Ceramicspeed oversize pulley wheel system. Moreover, if you still chose to get one, you would make it last longer with better maintenance - and at the asking price, this would be a really, really good thing!)


It might be possible to remove, clean and replace the cover. As Carel says, know you can replace the part before disassembly.

The Dealer's Manual for the REVOSHIFT Shifter seems to indicate the method for removing the cover.
Page 14 tells how to remove the cover.

Page 15 tells how to put it back on).

I left step 3 out for brevity. It tells how to remove and replace the cable.

I'd be tempted to leave it alone and shift by feel.


Can road bumps excite frame eigen frequencies?

A resonant frequency encountered on a road surface would be for the whole bike system, i.e. frame, wheels, rider etc. The rider is effectively attached to the frame via elements with spring, damping and active control properties (arms and legs). Bumps encountered at a specific frequency might buck the rider off.

Bicycle frames are pretty stiff so any undamped resonant frequencies they have would be relatively high. Certain not at 10 or so Hertz you may get from riding on regularly spaced road bumps.

You assume that all structures fail when excited at resonant frequencies. This is plainly not true, otherwise acoustic musical instruments would self destruct when played. There certainly are structures where resonances can contribute to damaging oscillations of course, but I don't think bicycle frames suffer from this.


I don't think that the exact laces are available under the Shimano brand, but the internet may prove me wrong.

The closest thing I have found online is oval athletic laces like these:

When I replaced mine I found similar laces at a sporting goods store, but I've seen similar sport laces at some of the big box stores as well. If you google "oval athletic laces" you should find a large number of online sellers as well.


How long is chamois cream meant to be effective?

It massively depends on the brand/consistency of the cream, how much you use, and the weather conditions.

For me, a small amount of Assos cream will last 4-6hrs in normal conditions, but if its particularly hot (and hence sweating a lot) or if its rainy it lasts much less.

There are some products that are much more durable (morgans blue solid for example), but are also not easy to wash out of shorts again afterwards.

I never carry any with me on a normal ride, but it is always in my day bag if i'm doing a supported tour.  If I was doing something properly long like PBP or LEL i'd definitely take some.


Disk brake brakes work poorly after annual maintainance

If the pads have oil on them they need replacing. The discs can be cleaned if done properly and carefully. If the LBS did the work, take the bike back and they should put it right.

From the sound of it, I would also be looking for another LBS. If they cannot service brakes and keep the oil off they are at probably sloppy - but even the best shops have the odd incident. However, as they returned the bike to you in that condition, it is dangerous, they have let poor work out the door. My future custom with them would be in serious jeopardy.....


Are bikes more prone to punctures after a spell of rainfall/flooding?

Yes, it's because the rain washes more debris onto the road which can then cause punctures. The wet tyres are also easier to damage (couldn't find out why but I guess because it softens the rubber)

Source: Bicycle by Helen Pidd


smaller wheels on big bike to reduce height

The first problem with changing the wheel size is surely the brakes. Assuming they're rim brakes, they won't be in the right place for a smaller wheel.

In any case, is it the distance to the ground that is an issue or the distance to the pedals? If it's the latter, then changing the wheel size won't help, however, you might get an extra 5 or 10 mm by using shorter cranks - if this is appropriate for your height.

I would imagine that it's probably better and not much more expensive to trade the whole bike in for one which fits you.


There's no right/wrong answer.  Just make sure you have some sort of towel available so you can wipe your hands before riding.

What I generally do is place dabs on the chamois and rub the sides together to spread it around -- keeps the hands relatively clean and doesn't require a separate applicator.  Some people prefer to rub it on their butt.

I don't use a lot -- maybe a half ounce (about 15 cc, IIRC).  Others use much more, maybe 2 oz.


Different wheel sizes have different advantages/disadvantages.  Larger wheels tend to roll over obstacles better (more comfort), and be more efficient once up to speed.  Smaller wheels (generally lighter) are easier to spin up to speed, more maneuverable for highly technical terrain and often thought of as stronger (owing to shorter spoke lengths).

While it's true that many (almost all) cross country and trail bikes have gone to the 29" format, many other categories have not or have only moved slightly away (650b|27.5").  Downhill rigs are now largely 650b or still 26".  Dirt jump frames are still largely 26" format as well.  Due to the nature of these disciplines, the smaller wheel format is more appropriate.

Like anything else in cycling, equipment should be properly matched to use.


Which mapping/route planning source should I trust for elevation

None of them will be "right"

Strava may throw away your elevation data depending on the device used to record it.   So for any phone-based app the height is ignored, and your track is placed on a map, then the known elevation is read off that.

For devices with known-good barometric sensors (Garmins and some others) the data in the upload IS used by strava.

The weather was horrible at the start, cold spitty rain.  About 20 riders simply chose to abandon before starting.   The rain cleared about level with "Lincoln" and the road was dry by about halfway.  So the air pressure increased, throwing the Garmin sensor out of calibration.  This rider had about 800 metres of climbing

  Here's my recording of the same event in March 2017. My recording shows 1820 metres of climbing, and this graph represents the real road elevation properly.

Furthermore you might think a map would be accurate, and in the main it will be.  Except the elevation of a map is based on contour lines, lines around the slope at the same elevation above sea level.

There is generally no continuous elevation data for a road.

Instead the map is divided up into square blocks and an "average" height for that block is calculated.  If the blocks are 1m square then its pretty good-enough.  If the blocks are 10m square, its "okay" because that's about the width of a roadway.  If the blocks are 100m square, then its terrible.

Consider this road with a 7% grade.   If the elevation blocks were much larger than 10m they could be positioned up or down the hill, giving an artificial high/low spot, increasing your recorded elevation gain.    The hillside here has a slope of about 45 degrees so its the same as a 100% grade.


Reinforced Shimano pin snapped before connecting chain - how to resolve?

You can often use the chain tool to drive the half-way inserted pin back out from the chain. I do not think it is advisable to attempt pressing it in again. It is certainly possible, I did re-pressed regular roller pins a couple of times when I or someone else accidentally pressed them out too far so that they fell off. It is not the most enjoyable experience, especially as the roadside repair.

You can get another reinforced pin and try again. Alternatively, you could get a so-called master link which replaces one of the half-links on the chain (presumably one at the end of your chain with the broken pin sticking out of it). The master link allows to close the chain using no tools at all, and often to open the chain using special pliers (or just bare hands, with enough swearing).

Several companies manufacture such links for chains of different widths (for cassettes from 8 to 12 speeds). They are generally compatible with chains of all vendors, e.g. you can use a KMC master link on a Shimano or SRAM chain with no issues.


It happened twice to me to be stung:

once a wasp entered from the neck under my loose shirt, and being trapped between the fabric and my chest didn't find anything better than stinging me.
another time I was cycling along the coast and felt a sudden burn between my thumb and my pointing finger. Something stingy was there and had the idea of sticking its harpoon into my flesh.

And if we don't consider stinging but insect accident in general...

another time, while I was speeding downhill, a bumblebee loaded with pollen splashed onto my glasses. Not painful for me, but my face was half covered with a yellowish goo.
while panting for a climb, some mosquito decided that my mouth was a nice place to rest (forever)

Now, I ride for more than 30 years, so I would dare to say, based on my sole experience, that mishap with insect are rare but can happen, and if they feel threatened they fight back.

Wear tight shirt to avoid them being trapped between the clothing and your skin, keep your mouth closed as much as possible, and wear glasses to protect your eyes. That should do for most of the cases.


Replace jockey on old XT RD-M750 or change out to RD-572?

I presume you are referring to the jockey wheels on the RD. These are not called 'sprockets'. They are not ceramic, though the guide wheel has ceramic bushings, while the tension wheel uses sealed bearings
The M750 RD is all aluminium and in comparison M592 is part steel (so slightly heavier), and uses cheaper jockey wheels. However it sounds like your jockey wheels are used up.
The other thing is M592 is Shadow which means no top pivot, which is a common wear point. Both are good, probably the shadow design is better, whereas M750 is a better implementation of the non-shadow design.
A new Deore RD will certainly be much smoother than a worn out XT RD. XT is more durable and lighter, but a worn out part is a worn out part.
If the RD has not had much wear in the pivots, but the jockey wheel has merely perished due to age then, you could just replace the jockey wheels in the old RD. But you don't say, so I'm assuming it's very well used.
The best possible solution would probably be a new 9-speed Deore XT Shadow RD, but I'd be happy with any Shimano 9-speed RD personally. (don't buy a fake one!) If you did get the M592, then you could upgrade the jockey wheels to XT grade ones for higher durability/slightly lower friction. The few extra grams from the steel cage is not really a big deal.


Creaky crank problem: Campag 11sp Athena crankset (Ultra torque)

This is a big question.

Clicks and creaks can be related to a good many things, sometimes the crankset and / or the BB, sometimes not.

Do the simple stuff first.

Check:

The cassette lockring is properly tight - it does need to be at the
correct torque, usually marked on the lockring iteself, typically 40
nm.
If it's a Campag wheel, that the end pieces in the axle are tight ... two 5 mm allen keys, one in each end, locked clockwise relative to each other.
The rear QR is tight - if it's some super-lightweight,
titanium job, replace it with something less fragile from a reputable
maker like Campagnolo or Shimano
Check the chainring bolts are correctly torqued. If Campag they use a T25 Torx key and should be at 8 - 10 nm.
Ensure that the pedal threads are greased and that the pedals are tightened to around 16 nm in the cranks.

Once you have looked at these areas, then the BB needs a look. First question - is it press-fit or screw-in type cups? From here on in, you are mostly looking at shop processes using the correct tools. Don't try work-arounds, they are very variable in their results.

First, drop the cranks off.

Remove the BB cups / press fit adaptors.

Measure the BB shell and check it is tolerance for width and if press fit, diameter.

If it's screw in, check that any movement you might have felt or seen is not a breakdown of the bond between the threaded BB insert and the frame itself - this can and does happen and it is not easily repairable in most cases.

If the BB insert all looks tight and immobile, chase the threads. If possible without touching the carbon, face the BB shell so that the cups are definitely coming up against flat, square surfaces.

Re-fit the cups with grease, Loctite 247 or copperslip on the threads and tighten to between 16 & 24 nm. Loctite requires lower tighteneing torques.

Reassemble the UT bearings into the cups with plenty of grease in the cup itself. Ensure the clip on the RH cup is fitted. Ensure the wavy washer is in place. Ensure that the central bolt is locked to between 42 & 60 nm.

If press bit BB, is it true BB30 or BB30 PF or some other variation?

If it's true BB30, remove the adaptors, clean and degrease everything, and refit the adaptors with Loctite 641. Reassemble the bearings and cranks as if with screw-in cups (see above) once the Loctite is dry (normally 24h) and see if it creaks. If the cups were the issue, this will fix it. Campagnolo have always recommended Loctite on their press fit cups but the recommendation has been largely ignored.

If it's BB30 PF or some variation on the same, the adaptors will be pressing into a carbon base not alloy, so they again need to be taken out, everything degreased a suitable activator (Loctite 7649) is applied to the carbon and the adaptors are then refitted with Loctite 641. Reassemble the bearings and cranks as if with screw-in cups (see above) once the Loctite is dry (normally 24h) and see if it creaks. If the cups were the issue, this will fix it.

There are a vanishingly-small number of riders for whom UT is just not the right system - some are so untidy in their pedalling style that they can side-load the whole assembly and induce an odd click or creak, but for 99.999% of users, proper and careful assembly and taking the steps outlined above will cure any and all noise.

HTH!

Graeme

Head Technician

Velotech Cycling Ltd, Campagnolo Main UK Technical and Service Centre.


this is Nick the owner of TriRig and the designer of the brake.

Short answer: yes, Omega X has been allowed to race in all stripes of UCI events, up to and including multiple appearances in the Tour de France.

So generally, it appears it has been ruled legal. Of course, there is some level of unpredictability in how any given commissaire will rule on any given day at any given event. We have heard a couple rogue reports of the commissaire requiring the Front Plate to be removed. But in general, you should not have a problem. Thanks!


What to buy for replacing missing fork top cap?

Normally I'd say that the top cap isn't strictly necessary, until you need to adjust your stem, at which point you need it to properly load the headset bearings. Water getting in there isn't much of an issue  as it would just flow out the bottom of the head tube. That being said, from the picture I have never seen one that looks like the one in your picture. It should look like the second picture from this post. In general you should not leave your bike in the rain, but water getting in the head tube wouldn't be a huge worry of mine.
It's also worth noting that not having a top cap could be a safety issue in the even of a crash. Any open tube would be much more likely to cut you if you rammed against it.
EDIT:
I was able to find the assembly instructions for that headset and it seems that this type of adjustable stem that you have doesn't require at top cap with a nut (see page 13 for bearing load adjustments). in this case the top cap seems to be purely cosmetic. See the top cap shown on page 25 in the exploded diagram.  You might want to look for something else to plug the whole with if you are worried about the possibility of the open tube being a danger in a crash.


How to fix this unusual looking valve stem to put air in the tire?

Your valve looks like a regular Presta aka 'french valve' to me. It's just a bit on the short side for your current rim.

I would recommend using a Presta valve extender, it could replace the small nut that is currently located on the valve stem assuming the valve hole in the rim wall isn't drilled out for a bigger size valve (the bottom of the valve extender will then push against the rim thus taking the function of the small nut that is currently installed). You could also just remove the small nut (once again assuming rim wasn't drilled for bigger size  valve stem) so you have a bit more room to install a pump. just make sure to depress the tire at the location of the valve as to prevent it from being pushed down when installing the pump.

Presta valve extender(example):

You could also try using a adapter to go from Presta to Dunlop or Presta to Shrader, if you remove the small (currently installed ) nut it looks like you should have enough thread sticking out on your current valve stem in order to install such an adapter.

Source

bonus info:
https://www.bicycling.com/repair/a20048610/the-difference-between-a-schrader-valve-and-a-presta/


Why do riders swing the bike out sideways when jumping?

It's a trick -- it looks good on camera and would count for points accordant with degree-of-difficulty and "sticking the landing" at an adjudicated comp. The bike and rider become effectively parallel with their upright-riding stance; as opposed to perpendicular when in contact with the ground.

It's also a marketing cliche in biking. Like an "ollie" or a "kick-flip" on a skateboard - landing this grants credibility and implies talent, courage, maybe stupidity ... depends on the actual vs. perceived talent level.

To be clear - cuz looks cool.


Busted Dept store Mongoose Shifter - Scrap or Fix

If it is easy to get the bike to a bike shop, it is worth asking the shop the cost of a replacement.  It is not likely to be more than a few dollars.  Otherwise take the old bracket to the bike shop to get the replacement to match.

If the bike shop is able to do the replacement on the spot, let them do it and watch how it is done, otherwise it is not hard to do yourself and will save you the time of having to collect the bike.

This you will be left with a cheap bike that you can ride.   You may still wish to buy a better bike, but will have the time to find a good one.


The Specialized shims are probably what you will end up using, however, before ordering them up, see if there is anything you can do by changing the location of the levers on your handlebar.

Drop handlebars can be adjusted in a multitude of ways. You can adjust the overall angle and slide the levers forwards or back to compensate for a change of bar angle, to keep the hood position where you are used to it being. Sometimes you can push the levers mounting position forwards/down, to interact differently with the curve of the bar to give a shorter reach. How exactly this works with your bike depends on how 'anatomical' or 'track style' your bars are. This will involve a lot of adjustment of bars, levers, cables and tape, but it is something you may want to investigate.

Alternatively go with the Specialized shims or simply rely on the fact that you can always reach your brakes if the threat is scary enough and slacken them off a bit so that, once you have got the lever, you are not working it with your fingertips to effect useful braking.


cleaning v-brake arms with riveted inner sleeve

I have had these brakes before, and what I've found to work is:

Take the brakes off the bike
Clean the bosses on the bike, inside and out with rubbing alcohol and a Q-tip (a.k.a. cotton swab)
Clean the portion marked in red with a q-tip dipped in rubbing alcohol. also clean the back surface of the brake (where the bolt is, but on the other side of the head in the same way). Be pretty thorough; you'll go through a bunch of q-tips until its clean.
Let the rubbing alcohol dry
Grease your brake posts and bolt, and re-assemble. I use regular old white lithium grease.

They tend to last about 2 years this way (but I think we probably have a lot more road salt and gunk in the Midwest USA than Germany), and then no matter what I did, I had to chuck them (which isn't a huge loss, they're pretty cheap).

The Single Digit 7's are more robust in this regard.


What can cause disc brakes not to react after keeping/moving the bike upright, then recover?

As always, it's hard to diagnose something with such a brief description and without looking at it, but the most likely cause is air in your brake system.

Brake systems are designed to work with your bike standing still, where any small amount of air is pushed by gravity to the reservoir of the levers, keeping the system working well.

When you move your bike around and put it in strange positions, or when you store it vertically, this changes, gravity now pushes oil into the reservoir and air to the lever. This means when you start riding there is actual air somewhere where it shouldn't be and the brake don't feel right. If you keep your bike still for a few minutes this "resets", and air goes back to the reservoir and the brakes star working ok.

On the beginning of a ride, and mostly if you store your bike vertically, you should always test the brakes and give them a few minutes for oil to go "down" and air "up", and press the levers a few times because this creates mechanical pressure on the lever so that it gets filled with oil and air is pushed into the reservoir. This is actual advised in some brakes manuals.

It doesn't hurt to bleed your brakes and take as much air out as you can, and now that you are at it, check if the system is well isolated, i.e., check for small spills of oil in the calipers and levers and around the tubes. A problem in the system is not a likely cause as the brakes would always perform poorly instead of only after you moved your bike, but it doesn't hurt to take a look.

Happy riding!


Broken rear brake - told it was unfixable

The brake pivot broke off the frame in a very unusual way. A framebuilder may be able to contrive a pretty cheap way of fixing it by putting a new pivot stud in. This would still require removing the paint in the area, but it wouldn't necessarily be that bad.
Minimum prices for framebuilders to even get into repair j jobs are typically in the $100-200 range in the US depending on where you are. It's the kind of thing where a simple and fast fix may be possible but the equipment and skill to achieve it are costly.
Removing and replacing the canti braze-on entirely would be technically easy but far more time consuming. The offset needs to closely mirror the other side, so either both would need to be replaced or the left side replacement would need to be carefully selected and/or modified.
The bike shortage situation is such that some things that weren't worth it in the past might be now.
You could also fix it by just putting a long reach BMX sidepull caliper on the back, like an Odyssey 1999. These are mediocre brakes but this would be a cheap way to get it functional again. You would need to be careful to get one with long enough reach. To be honest this is a pretty obvious path and it doesn't speak well of the shop to not suggest it, unless they did the measurements and found it was longer reach than brakes exist for. It doesn't look like it though.
I see what happened and would not hold the shop at fault for it breaking in the first place. The main way for it come off like that is poor brazing at the factory.


Are older road bike parts compatible with newer standards? How do older and newer bikes match up performance wise?

Upgrading an older bike is typically not economical.  Parts are typically not cheaper.  Parts are not as available.  That drivetrain is not compatible with a modern bike.  Bikes have gotten better.  Little faster, lighter, more comfortable, and easier to service.  You can find decent to nice newer model used bikes for $400.  Find someone that bought an $800 bike thinking they were going to get healthy, did not ride it, and is selling it for $400.  It happens and that is your best value.


What to get? How do I know whether what I'm looking at is a BSO? (Bicycle Shaped Object); what should I do about the multiple chainrings?

That Munich "21-speed" is really a 7-speed. It doesn't have a triple chainring or front derailleur (and doesn't seem to have a planetary-gear rear hub). Not sure why they call it that.
Both bikes seem pretty comparable. Decathlon is well-known in Europe as selling cheap but decent products. I've never heard of Mach City. If a brand's reputation is worth anything, that's something to consider.
One of the hallmarks of terrible BSOs that I've seen in the USA is thin stamped dropouts with tubes that are pinched onto them (see below). Neither the Mach City nor the Decathlon bike seem have this kind of construction. Another hallmark is the one-piece crank.


Shimano Deore 2x10 derailleur M6025-L with 3x Alivio M4050 crank

Yes, it will work, but not optimally.
According to the bible:

"Double" front derailers will work with triples, but if the middle ring is much smaller than the big ring, they will be balky shifting up from the small to the middle chainring.

Several options:

Drop the smallest chainring. You won't need it anyway. I have done this and I'm happy with the result.
Learn proper front shifting technique and live with the poorer shifting of the double derailleur on a triple crankset.
Find a triple front derailleur.
Find a double crankset.

I used to have a very cheap bike with a double front derailleur and triple crankset. The diminished front shifting performance was not noticeable because all of the components were so poor that every shift was poor anyway, even in the rear!


FSA Omega MegaEXO Press fit BB 19mm removal (non standard BB86)

I contacted FSA and was told no tool exists for pressing/removing the 19mm BB. So I proceeded with the cave man approach:

I used a long 3/8" extension (female side against the BB bearing) and hammer to knock out the left side, it came out easy.

The right side was a challenge with the same setup (it would not budge) , I ended up punching the bearing out of the BB shell.

I got the rest of the shell out with a 22mm deep socket and a short 1/2" extension and the same hammer technique. I would advise using a large socket that fits as soon as you get one side of the BB out.

The bearings/bb does not appear to be damaged and could be reused.


Comparing mini pumps - what to look for and what to consider?

You need a pump that pumps air, to the pressure you ride at, through the valve system you have.  And you need that pump on you or your bike, not at home.

Lighter weight is nice, but super light tends to be weak and bendy.

Some pumps allow the use of CO2 which sounds nice, but gets expensive.  Plus that tyre will be low/flat the next morning. So carry a pump as standard and a co2 inflater as optional.

I have 4 bikes.  At a minimum, each has its own pump, tool kit (multi tool, 2/3 tyre levers) one spare tube, and stickers.   That way I don't get stuck somewhere without the bare essentials.   Consider this, should finances stretch that far.

Mini pumps generally come with a clamp that fits under the bottle cage mounts, or some have more unusual mounts.  There's a risk the pump gets stolen if you leave it there, or may vibrate loose and fall off while riding.  A velcro strap helps, or a ziptie that you cut off in time of need.


You can determine the proper chain length by following the technique used to size chains when they are installed - in a modify way, as you will have a joined chain.

Before doing that make sure the B-screw is adjusted correctly so that the upper jockey wheel is not hitting the largest sprocket.

Put the rear derailleur on the largest sprocket, take a couple of chain links and pull the chain taught (it may help if you have someone hold the derailleur cage to remove its tension. You should be able to pull two plates together so that they would be joinable with 2 links (one inner, one outer) of axtra chain between them.

I'd also check the spring tension in your derailleur, both the A pivot where the cage rotates and the B pivot where the derailleur rotates on the hanger.


Rear derailleur does not downshift properly, shifts up smoothly

This looks like a classic case of the cable sticking in the housing momentarily as the shifter lets out cable to downshift.

Your indexing looks fine as the chain is not rattling or trying to shift on it's own. FYI the derailleur high and low limits do not affect shifting or indexing.

Try removing the cable, wiping it down with a clean rag, applying a little chain lube and reinstalling. If that does not work replace the cable and housing. One cable and a length of housing is not expensive.


If the bike is three or four weeks old it is most likely due for an initial readjustment. It takes a few weeks for the cables to stretch a bit and the derailleurs and springs to seat. This is why most shops want you to return the bike after a month or so to retorque the hardware and readjust the shifters usually for free.


How to change a Gary Fisher Kaitai Dual Sport to be faster on the road?

I changed the tyres on my MTB for slicker ones, The difference was very noticeable and more comfortable. Running higher pressure in the tyres also helps, but be careful not to exceed the tyres recommended max. Also I would recommend reducing the weight if you can, remove any unnecessary parts


How to keep my testicles from freezing on a recumbent

First: merino wool boxers. EDIT: Also windproof boxers, see other answer below

Second: Vest and short tights are very little for ~5°C, raining. You are losing a huge amount of body heat through your arms and legs, and this leaves little for body parts without active muscles. Wear more, and your balls will be warmer too.


When is it time to replace my trainer tire

I wouldn't hesitate using a tyre in that condition on the trainer, in fact that's exactly the sort of condition i might expect to start using a tyre on the trainer.
The small cracks likely mean the rubber is deteriorating and may be less grippy, but that's of little worry.  It's very unlikely there is substantial damage to the actual carcass of the tyre.
Finally, the absolute worst case scenario is a small split begins, the tube pokes through and bursts - however positioned where they are there is very little chance of the beads becoming unseated.  So maximum damage is the embarrassment of explaining to people you got a flat on the indoor trainer.


Its called a "step through" frame, and was initially intended for women wearing skirts.  Notice the skirt guard in the upper-left corner of the rear wheel.

There's no connection with Asia at all, would have originally been English and European.

The curve of the top tube does allow a little more flex, damping out vibrations a bit more.

As for comfort - it really makes no difference.  There's probably a fraction more side-to-side flex than a high top-tube diamond-frame, but the added damping is a positive.

Really cheap and bomb-proof are likely to entail a lot of weight by using additional metal.  That alone might make for a heavy ride.


Headset stiff when the bike hasn't been ridden for a while

It sounds like it needs a service, which is pretty easy to do. There is likely to be some dirt built up in inside, perhaps as a result of some water ingress, or because the grease is old and gumming up.
It's likely that the movement warms the grease up, and lets it move freely. it will need a service sooner or later. This is something you can easily do yourself, and it's likely to benefit from a cleaning, and a smear of new grease.


Could two identical bikes require different pin positions for front derailleur cable routing?

For the most part every bike model will use the same position for the converter.

What the converter essentially does is give some adjustability to account for different points of origin off the BB shell area for the final run of exposed cable before the BB anchor, because the derailleurs that feature converters have an anchor point whose lateral coordinate is very close to directly over the pivot of the actuation arm and are thus more sensitive to how the angle of approach of the cable affects the total throw of the cage, compared to traditional derailleurs where the anchor is more off to the side of the arm pivot.

Because these derailleurs are sensitive enough to this angle to require all the fuss of a special tool etc, it's conceivable that in some cases that small variances in layup, the exact position of a cable guide hole in the BB shell, etc, could cause enough variance for different bikes of the same model to need the converter set differently. And it would be very likely for this to be overlooked in a factory assembly setting.


How difficult is it to install internal seatpost drop cable housing in 2018 Specialized Epic Comp?

I've never run a cable this way, but I would imagine that it depends on the bottom bracket. (You already know that, which is why you're asking!)

Here's a quick look at a bunch of different models of cartridge style bottom brackets from Google Images:

From this quick look, we can see that there is a differential between the internal diameter of the bottom bracket shell (into which you screw the ends of the bottom bracket) and the diameter of the bottom bracket cartridge's "waist". For some bottom brackets, like the third and fourth ones in the second row (Velo Orange and RPM respectively), that diff is pretty small, so there won't be a lot of room between the cartridge and the frame. For the top left and top right ones (Sugino 75 and Shimano UN55) there appears to be more room. Whether it would be enough to run cable housing without putting too much pressure on it, I can't say - again, it would depend on your particular bottom bracket.

If you were able to replace the bottom bracket with the old cup-and-cone style, there'd almost definitely be room, but I can't imagine it'd be easy to find one that fit your particular bike :)

If this is your bike, I found an instruction manual that will help. One of the instructions says to "Work the housing over the bottom bracket shell and up the seat tube until it exits at the top of the seat tube", which indicates that yes, your particular bottom bracket should accommodate this cable run. Note that according to those instructions, you run the cable itself first and then to run the housing over it, which is a bit counterintuitive but it makes sense once you absorb the whole process.


Are all rear DI2 shifters / derailleurs / internal gear hubs interchangeable?

Looks like Shimano provides a handy guide: https://bike.shimano.com/en-EU/e-tube/project/compatibillity.html
source
Posted here since Shimano is already deleted it:


On recumbent trikes, vs road bikes which is safer down hill?

Safety on descents is more a matter of your state of mind than any objectively measurable phenomenon.

I will say that I have descended pretty damn fast on a road bike, and faster on a tadpole trike. This had less to do with being on three wheels and more to do with having an extremely low center of gravity on the trike. I've also never experienced speed wobbles on my trike--I'm not even sure that's possible.

You do not tip on a trike or bike when you're going in a straight line. If you're going through curves, the fact that you cannot lean into a turn on a trike means that you can flip the trike instead, and at higher speeds, you'll flip the trike on shallower turns.

Typically, tadpoles have two front brakes, and for the most part, this is a benefit. Braking at very high speed will steer the trike into the braked wheel; if you apply both brakes, then the slightest discrepancy in the application of the brakes can cause a dangerous back-and-forth when you're whipping downhill.

From what I've seen, a tadpole can be designed with a lower center of gravity than a delta, which improves stability.

If the road surface is too broken up or littered with debris for me to descend at full speed, then I don't, regardless of what I'm riding. I suppose in the abstract I would feel more endangered hitting a given rock at speed on my road bike than I would on my trike (I also have much fatter tires on my trike). It would also be harder to avoid the rock on my trike (three tracks vs one). But that's a hypothetical I am not eager to test.


Definitely something very wrong there.

The derailleur cage appears twisted around a vertical axis (the 'front' of the cage seems to be pointing outwards). A bent derailleur hanger typically rotates the cage around a horizontal axis (kicks the lower jockey wheel inwards). That makes me think the derailleur is bent rather than the derailleur hanger.

Do you have the old derailleur? Install that and see if the cage is parallel with the chainrings by looking down he chain-stay as in your first picture. If the old derailleur cage is parallel, the new derailleur is damaged.


The only scheme I know of is called planetary gears, or as Wikipedia calls it Epicyclic gearing. @Daniel suggests that there are other designs.

Here is one of the images from Wikipedia:

The inner gear is called the sun and the gears that go around that are called the planetary gears. In the basic design (the original Sturmey Archer design) the sun was fixed to the axle, and the pedals could either drive the assembly that the planets are on, or the outer ring. The wheel could be driven by the outer ring or the planetary assembly. A moving selector device controls the mechanism. The gear ratios were 1:2/3, 1:1, 1:3/2.

Thanks to @RoboKaren for editing in the image.

For more details, see the Wikipedia Sturmey Archer page, the Rohloff Speedhub page, and the Hub gear page.


Dahon D7HG Handlepost hinge loosens pivot point

Please review the following two references as it possibly your D7 may be fall within the questionable Dahon models:

http://www.performancebike.com/images/performance/web/pdfs/Dahon_Folding_recall2009.pdf

and

http://www.thorusa.com/dahon/technical/recall.pdf

(Dahon enthusiasts have a blog as well that may be accessed through the manufacturer's website and is useful for service tips as well.)


Wheel diameter affects speed? Comparing 20in Foldie wheel vs 700C wheel

There are at least four factors involved:
1. Tire pressure
The thinner the tire, the higher pressure it requires, and the higher pressures it can handle. More pressure means less deformation, and less deformation means less energy loss. Road bikes typically have very thin tires that allow pressures around 10bar, if I'm not much mistaken (you can look that up on the side of any tire), touring style tires are around 5bar, mountain bike tires even lower.
2. Tire geometry
The diameter of your wheel also plays a role: With a smaller wheel diameter, you get a shorter contact area with the road. That's simple geometry. Because the total area of the contact only depends on tire pressure, a shorter contact area means that it's wider. And a wider contact area means deeper compression of the tire, which again means more work that's expended for massaging the rubber.
3. Posture (aerodynamic)
At 25km/h, the strongest force holding you back is the air drag. And the more upright you sit on your bike, the more air you are accelerating as you pass by. Road bikes typically have a low bend sitting position because they are designed to be ridden at much higher speeds where air resistance is an even greater concern.
4. Posture (ergonomic)
To put your full weight onto your pedals, your center of mass has to be over the front part of the pedaling circle. With an upright sitting position that's generally not the case. The result is that some of your pedaling forces are translated into forces that try to rotate your body and to shift it backwards, which you have to compensate with your arms and butt.
The forward-bent position of a road bike does a much better job at putting your center of mass where you need it, and thus reduces the parasitic forces, allowing you to just use your strength to turn the cranks. This translates into more power output with the same subjective effort.


Essential maintenance for my bike whilst on a long distance tour

This will depend on what kind of conditions you're riding in, what condition your bike is in, etc, but I think these are the basics:

Air up tires daily.
Lube chain. How often will depend on what kind of lube you use, which is one of those religious debates I prefer to avoid.
Check headset for looseness. This actually was an issue for me. Also check bearing cones (if you have loose bearings) on your hubs.
Check wheels for trueness, spokes for tension.
When you get a flat, make sure to remove the offending pointy thing from your tire. This can be harder than it sounds.
Check frequently (every time you stop) for slow leaks. I destroyed a tire prematurely because of a slow leak.
Check tightness of rack fixtures daily.

Naturally other things can go wrong, but I think these are the main things that you can rely on going wrong or needing attention.

And don't forget maintenance on your body. Be prepared for sunburn, saddle sores, hotspots on your feet, muscle aches, etc.


Can I use an inner tube that's too narrow for the tyre?

In my experience smaller ones go in fine and last as per normal (not that I have pushed this to extremes with a 700x20 in a 700x40 but I only have 26x1.5 MTB tubes and they work fine in 26x2.00 tyres).

Allegedly putting a smaller tube in the tyre becomes a problem if and when you repair it, the patch doesn't necessarily stretch with the inner tube and it can come off.


On SRAM/Avid brake bleeds it's not normal to have fluid come out when disconnecting the caliper syringe beyond about what you'd expect the bleed screw to displace, or some drops in other words.

When you're doing that, is the lever syringe clamped still clamped shut? (It should be.)

Does each syringe connector have an o-ring and each bleed screw have an o-ring? If any are missing at any point, that's a way air can be introduced.

Have you visually checked the hose for damage? Checked banjo bolt for tightness? Checked the barb/olive/nut assemblies are as they should be? Losing a ton of fluid at the caliper end when you disconnect the syringe raises the question of whether there's a leak somewhere.

When you do the step where you push the caliper syringe while you hold the lever syringe upright, are you applying gentle downwards pressure on the lever syringe plunger, and being sensitive that it is indeed moving up in correspondence with the pressure you're applying at the caliper? If the lever syringe wasn't moving freely during that step, the fluid could get pressurized and maybe spill out that way. Sometimes syringes can get sticky and you can fix it by taking the plunger out and lubricating their seals with brake fluid.

There aren't really any differences between the front and rear procedures. With SRAM brakes it's not supposed to make a difference how the ends of the system are positioned (unlike some systems where you want the lever to be the highest point and the caliper drain plug to be the lowest.)

Doing the actual air bleeding steps, where you push the plunger hard then pull up to coax out air, is a bit of a skill that takes practice. Importantly, you have to get a sense for when you're not seeing anything further because you've actually gotten all the air out versus because you haven't tried hard enough. It's a good idea to tap all throughout the caliper and lever with the back of a screwdriver or similar during these steps, to loosen any pockets of air that might be present.


Many bike shops actually offer demo saddles so riders have a chance to try them out without buying them.  You should call around any see if any of the shops in your area offer such an option.

If you can't demo the saddle, the first thing you need to figure out is why your saddle is uncomfortable.  Saddles can be uncomfortable for two main reasons: because there isn't material where you want it, or because there is material where you don't want it.  When you're sitting on your current saddle, where are you feeling pressure.  Ideally, it should be on your sit bones.  If it isn't, do you need a saddle that's narrower or wider?  If you're having issues with numbness, you might find it beneficial to adapt a saddle with a cutout.  If you're experiencing chafing, you probably need a narrower saddle with less padding.

You may also wish to examine the angle of your current saddle.  A typical rider will want to have the saddle horizontal, but even a few degrees of tilt can make a huge difference.


The fact that you've left the bike out in the rain the whole time and that the chain is rusty suggest that you've not been looking after it. It doesn't surprise me that it would now be damaged beyond economic repair.

I used to have a Trek 721, which I think is a predecessor model to the FX2.  Mine was kept under a roof and lasted longer than yours but, after several years of use, it too hit the point where enough stuff needed replacing that it wasn't worth doing so.  From the way it's been treated, it sounds plausible that your bike would now be at that point, too.

I suggest that you take it to another bike shop for a second opinion and then decide how to proceed.  Assuming that they say essentially the same thing, you have two options: either pay half the cost of a new bike and have a bike that will work for maybe another six to 18 months, or pay the whole cost of a new bike and get a new bike.


Normally when you disconnect a brake hose (eg to install a new caliper), you are well advised to replace the 'olive' with a fresh one to ensure a quality seal. Shortening the hose also needs a new connector insert but you don't say you're doing that in the question.

I would treat this as an installation of a brake and follow the relevant steps in the dealer's manual, noting that Shimano states that "This dealer's manual is intended primarily for use by professional bicycle mechanics."

You shouldn't lose much fluid out of the hose if you disconnect only one end at a time and don't squeeze the lever, then I would give it a bleed as per manufacturer's instructions to remove any air. I don't know if the new caliper came with any fluid in, but by doing a full install and bleed it will fill up and purge any air you might introduce.


Wipperman connex master link on a shimano chain?

It should be safe as long as the widths of the chain and the master link are the same. That is, if the chain is 10-speed, the master link must be 10-speed, and so on.
From the legal perspective, I do not think that either vendor (Shimano/Wipperman) will accept warranty claims in a case when something would break. Unless they specifically claim such compatibility, of course.
From the practical perspective, as long as the pieces are geometrically compatible (the aforementioned link width and the pin/rivet diameter), they should work fine together.
From my experience, I've used various SRAM/KMC/Wipperman master links on various non-matching Shimano/KMC chains without issues. Things did break occasionally, but so is the name of the game for me.


How do I remove the axle protector after shipping

After growing somewhat impatient, I grew a pair, set the fork (protected by the guard) on the ground, set my foot on the protector, and pulled up on the legs as hard as I could. It came off, but as a cautionary note to anyone else with this problem, I took a brake to the shin. Watch your shins


3 Speed Front Derailleur can't reach small gear

The chainwheel does not sit at the correct chain line is the answer.

The most common cause is that you have an axle length shorter/longer than the ideal chain line. In this case, you have a shorter axle length.

Did you add another chainring into your crankset? If the answer is yes, you will need to tweak around: either adding spacer (not recommended) or find a compatible front derailleurs (better get to the LBS for trial/error fitting).
If the answer is no, then it will be the frame that cause you the problems, albeit unlikely. I always solve this problems by finding a correct axle length for my crankset.

You can refer to this article for more information, from Lord Sheldon.
http://www.sheldonbrown.com/chainline.html


What are the different types of bottom brackets?

I think that in answering this question, it's important to understand that the differences in bottom brackets themselves is partly due to the cranks that match said bottom bracket 'doing more of the work', so the crank and BB need to be seen as a system for the whole picture.

One-piece cranks ("Ashtabula")

In this system, the crankarms are a single piece of metal bent into a "Z" shape, with threading on parts of the spindle section of the crank (the part that goes through the frame). Bearing cups are pressed into the frame, then the crankarms are inserted through in one piece. bearings go between the frame cups and cones that thread onto the crank spindle. The Park Tool One-Piece Bottom Bracket service page has lots of nice pictures that might help figure out how things go together.

Three-piece cranks

These cranksets consist of a left and a right crankarm, which both attach onto a spindle which is part of the bottom bracket. Usually these BBs will thread into the frame, with the majority of the assembly being one piece that threads into the drive- (right-hand) side of the frame, and then a (usually plastic in the case of Shimano bottom brackets) supporting piece will thread into the non-drive-side to take some of the load off the drive-side threads.

Examples of spindle systems for three-piece cranks are square-taper (both ISO and JIS standards), Shimano Octalink splined and ISIS splined. These BB standards all thread into the frame. The crankarms usually attach to the spindle via a bolt that threads into the end of the spindle.

Two-piece cranks

In recent years, most higher-end cranksets have switched to a construction where the spindle and drive-side crank/spider assembly are integrated into a single unit. This means that the bottom bracket no longer needs to have a spindle, and is now essentially a pair of bearings that support the crank spindle. The variation in where these bearings are placed, their size, and how they are mounted in the frame causes the wide range of modern bottom brackets.

Narrow-diameter spindles (≈ 24 mm)

Shimano's Hollowtech II and FSA's MegaExo both use a spindle diameter of 24 mm, and are most commonly used with external bearing BB's that thread into the frame, such as the SM-BB70 you mention.

SRAM's GXP system uses a 24 mm spindle on the drive size which narrows to 22 mm on the non-drive side, which they say avoids having to adjust the axial loading ('preload') on the bearings during installation.

Large diameter spindles (30 mm)

In the search for lighter and stiffer cranks, the diameter of the spindle was increased to 30 mm from the previous 24 mm. However, the cartridge bearings for a 30 mm spindle have an outer diameter that is too large to be attached with threaded external bearing cups, so most new systems moved to 'press-fit' BBs. There are a number of standards, the first of which was Cannondale's BB30, where the cartridge bearings are pressed directly into a machined bottom bracket shell in the frame.

However, because the manufacturing tolerances required to achieve a good fit for the bearings in a BB30 system are very tight (and therefore expensive to manufacture), other manufacturers switched to PF30, which uses the same cranksets as BB30 but rather than pressing the bearings directly into the frame, plastic bearing cups are pressed in first, and then the bearings are pressed into the cups.

Mixtures

Very recently, FSA have introduced their BB386EVO cranks, which have the same diameter spindle as BB30/PF30 cranks, but the spindle is wider. The wider spindle means that FSA can offer a BSA threaded frame to 30 mm crank bottom bracket, but that the crank can still fit to BB30/PF30 just by adding spacers to the spindle to make up for the narrower BB width of those standards.

There are also standards, which I do not know as much about, which concern press-fit bearings sized to accept 24 mm cranks, including "Shimano press-fit" (colloquially BB86 or BB92), and Trek's BB90, which uses slip-fit bearings like an integrated headset, as opposed to bearings that must be pressed in with force.

Campagnolo

Campagnolo produce three types of cranksets at the moment. Power Torque is their name for a two-piece crank similar to Shimano Hollowtech, however the bearings are not part of the bottom bracket, instead they are pre-installed on the crank spindle before it is inserted into the frame.

They also produce Over-Torque, which is a 30 mm spindle design compatible with BSA threaded frames and most press-fit systems, and Ultra Torque which splits the spindle in two at its midpoint.

(Apologies for the lack of detail in the Campy section.)


Upgrading cycle from single to multi-speed

Some problems in your plan that I can see from the pictures.

There is no rear derailleur hanger provided on the rear dropout. Without it, you cannot install a rear derailleur.

There seems to be no place to install more than one rear cog, as the rear hub is designed to take single speed BMX-styled freewheel.

Without the possibility to have a derailleur and cassette, you might want to have a rear internally geared hub. This means replacing the whole rear wheel. The new hub has to have the same width as the old one.

To install a front shifter and multiple chainrings, you will have to replace the existing crankset and the single chainring it has with another crankset that can take two or three chainrings. Then, these two/three rings should also be bought and installed. None of existing parts can be reused.

It is not clear from the pictures, but most likely to install the front derailleur you will need an adapter on the seat tube. Even with such an adapter, it is not clear if the front derailleur will be in a right place to work.

A narrower chain is often required if a cassette is used.

A method to draw and attach shifting cables along the frame from shifters to derailleurs or the hub has to be devised.

The list of possible modifications is already so long that implementing them while being on a tight budget is impossible. At this stage, selling this bike and getting another (used) one with gears is indeed the cheapest approach.


Is my rear cog wobble the fault of the axle, the hub, the bearings, or the wheel trueing?

I think you have a bent rear axle.

Looking at your rear block it does not have a lockring on the cassette, so its likely a freewheel  (ie the clicking part is integrated with the gears, not part of the wheel)

This means the axle is less-unsupported on the right hand side, and they bend easily.

Here's a pic - the red circles are the ball bearings, and the freewheel axle (schraubkranznabe)  has a long lever arm of 2-5 cm compared to under 1 CM

The upshot is minor bumps and regular riding are enough to deform the rear axle over time, right where the bearings are.

As such, the rear wheel oscillates because the bearing cone on that side is no longer equal distance from the bearing cup all the way around.

Your fix is a new rear axle for $20ish but it could happen again.   The longer term fix is to replace the hub with a cassette-based wheel.

Or simply ride it like it is and keep your eyes open for another rear wheel.  The bearings will munch themselves over time, and the cone will get pitted and damaged, but as you rightly point out, its a BSO.


Spokes are too long for wheel build. What did I do wrong?

The spoke lengths were correct, I just laced the wheel wrong. I fix the lacing issues and now the wheel is looking good.

If you ever suspect that your spoke lengths are off, just make sure you laced the wheel correctly first.


How can I tell if a helmet will be comfortable before buying?

Put one on your head, adjust it to fit, and then try to slide it off your head in all directions. If you feel any pressure points or hot spots, you then need to determine if that will be alleviated by the little bits of foam included with most helmets, or if you need a different size or model of helmet.

As far as long-ride wear-ability is concerned, when you try on a helmet you need to be very aware of places the hard foam contacts your head. You also need to be aware of the weight of the helmet and ventilation when you start thinking about long rides. In most cases, for rides longer than about 2 hours, a more expensive (read: lighter and more ventilated) helmet will be more comfortable IF and only if it fits ok on your head.


How does one remove a old French (Maillard) sprocket set from its freewheel?

You are correct, the smallest sprocket is threaded to the freewheel on the old Maillard freewheels.
Using two chain whips, one on the smallest sprocket, one on the next one up or a few farther. Unscrew the smallest sprocket, it is a standard thread.
The second one will also be threaded so repeat the above steps.
Here is a diagram for the Maillard 700 Course, Compact and Sprint

www.cyclollector.com


Just how much difference does your bike make?

Bicycles, like many machines, are efficient, but a large amount of energy converted by them is not in fact used for their "intended" purpose: The largest energy sink is air/wind resistance, which you can only very marginally improve on a "normal" bike†. However, wind resistance squares in relation to your speed, so maintaining a more leisurely pace would improve your efficiency. For example, people riding on cross-continental tours actually ride pretty slowly compared to e.g. people riding a road bike for training: They do this so that they can put in longer distances over the whole day rather than pushing themselves as hard as possible for e.g. 5 hours and then being destroyed for at least a day.

The second biggest contributor to the bicycle's lost efficiency is rolling resistance, as you seem to already realize; Therefore, getting a bicycle with proper road tires will drastically improve your riding speed and efficiency over riding a bike with heavy-tread mountain bike tires. As a real-life example, I can easily handle 50+ km in a few hours on a 40-year-old ten-speed without really "pushing" myself past my limit but on a mountain bike this would probably kill me.

Lastly, weight is very important when riding over hilly terrain but less important on the flats. However, you stated that you are riding over hilly terrain, so reducing overall bicycle weight might actually make a big difference for you even if it doesn't improve actual mechanical efficiency much: Humans are extremely complicated machines and we only have a very narrow power band, quickly becoming exhausted once we leave this particular "sweet spot" of cadence and load: If your cadence is too high you run out of breath but if your load is too high your body starts using anaerobic power and builds up lactic acid in your muscles, which wears them out.

TL; DR

If you have the money, go look for a decent used road bike (even if it's old, it's likely going to be more efficient than a fancy new mountain bike)-- if not, go look for decent road tires for your current bike. However, no matter what you do, ride your bike at a casual pace because you'll go further without getting worn out.

† You can significantly reduce wind resistance by riding a bike with full fairings but, for your stated purposes, this would be a bit ridiculous.


We deal with bicycles here, and you're looking to replicate the early motorised bicycle (ie on the way to being a motorbike.)

Speaking generally, you need some way to put that power from the motor into drive, but to not compromise the function of the pedals and brakes.

  As soon as you can't pedal it, then its a motorbike.

So the common way to wet-fuel power a bike is to chain drive the rear wheel through a freewheel threaded or bolted on the left side of the bike rear wheel hub.  Another way is to run the main chain through an extra sprocket.  Or you can use a rubbing wheel to push the back tyre around (this one can work on the front wheel too.)

You want a freewheel so that the back wheel doesn't drive the motor when starting from stopped, and you need a clutch in the motor to stop the motor stalling when you're standing still (at traffic lights etc.)

Most liquid fuel bikes cannot be started from stationary using the motor - you generally have to pedal or scoot up to 5-10 km/h and then release the clutch else the motor's RPMs are too low.

You absolutely want a throttle too.  Most chainsaws are ON or IDLING or OFF.  Really you want more levels of power between "Full blast" and "stopped"   And that throttle really must be on the handlebars for safety, not on the motor body.

Fuel tank becomes an issue too - you might have to relocate it from the chainsaw to somewhere further forward on the bike, to help with weighting issues.  Bike should be weighted ~40% on the front wheel and 60% on the rear wheel when ridden level.

A big consideration is BRAKING your bike will be able to stop itself and a rider in the dry from X km/h to 0 in y metres.   As your speed increases the stopping distance blows out.  Also the additional weight of the motor system will contribute to increased stopping distance.

  Uprate your brakes!

Continuing to pedal is another important safety suggestion.  Cars more-so will have a harder time seeing you as a moving object if you're just sitting over the bike.  If you're pedalling you look more like a moving thing.  Don't just potato-sack on the bike.

Legal - your location may regulate maximum power.  For me I can have up to 300W of electric or 49cc of petrol power+pedals wuithout having to register.  As soon as the bike hits 301W or 50cc or looses its pedals, then its a motorbike requiring registration and WOF etc.   Find the legal limits and don't exceed them.

I owned an electrified MTB for a couple years and it was a fun learning curve.  Some things I learned

Motorists, pedestrians, and other cyclists glance, see a fat man on a MTB and assume I'm trundling at 10-20 km/h.   In reality I could do 45+ km/h so there were innumerable times something would pull out or step out in front of me.  Ride defensively.
Wheel spin - in the wet or damp, and even just gravel was a lot more slippery.  It was massively easy to spin the wheel without getting traction.
Running out - you're on a bike.  If the wet fuel runs out then pedal.  Most countries will require a bicycle to have working pedals.
Locations - depending on your location, you may still be disallowed from bike paths and cycle lanes.  Check your local legal laws before implementing a build.