My rim exploded inflating on an automatic pump of a gas station. Should I reuse wheel's spokes/hub or buy everything new?

I don't know what kind of air pump you were using at the gas station. If it was a manual one with just a pressure gauge attached, you can usually use them if you are careful enough.

Automatic air pumps, however, usually have the habit of using this three step algorithm: 1) open the valve to fill some air for a fixed amount of time, 2) measure the effect, 3) correct the error. Problem is, that step 1 is adapted for car tires with their immense volume, so it will over-inflate the tire if the pre-pressure from the pump is high enough. Typical pre-pressure from pumps seems to be around 100psi (my experience), but it can be anything. If your tube has a dunlop valve, that extra pressure will remain in the tire. So, don't use automatic pumps, especially not with dunlop valves.

That said, your rim has a maximum force that it can withstand. And that's where it gets a bit complicated:

The maximum force that the rim can withstand reduces over time if you are using a rim brake on that rim. It's not just the brake pads that wear away, it's also the rim. Give it enough wear, and it will even explode at its originally rated pressure. I'm not sure whether that's the case with your rim, though.
The force the tire's bead exerts on the rim depends on both the pressure and the width of the tire. The wider the tire, the more the tire will tear on the rim's edge. Your tire seems to be of the wider kind, so, even if the rim could bear a slim 100psi tire, 100psi with your wide tire may have been too much for it.
The force on the rim is independent of the tube. The tube is not designed to withstand any forces, the only force that it exerts is the pressure of the air. Whether the tube is folded or not does not change this pressure. So, the opinion of the second bike shop seems to be wrong in this regard.

So, what does that mean for repairing your tire? Well, obviously, you need a new rim.

Looking at the damages to the rubber covering the bead, I would have trouble trusting the bead to remain seated: I would think that the rubber between the bead and the rim does help keeping the bead in place. Without that rubber, I would fear that the bead might have an easier time slipping over the rim. So, I would replace the tire if I were you.

Regarding replacing the rim/tire/tube vs. just replacing the entire wheel, it's a lot of work to rebuild a wheel. If you don't do that yourself, buying a new wheel should be cheaper unless you have a sufficiently expensive hub like an internal gear hub to set off the expenses for work time.


"ETRTO" stands for "European Tire and Rim Technical Organization" which means that's an industry standard sizing number.  You can just take your wheel to your local bike shop and get them to spec a replacement rear wheel of the same size.

If you want more detailed information, unfortunately Specialized (unlike some nicer brands) doesn't appear to have an easily accessible catalog of old products to search in. However there's a site called Bicycle Blue Book (presumably based on the Kelly Blue Book for cars) where you can search for previous year models.

You're probably not interested in the valuation, but the page for each bike includes product details, so you can make sure you're getting a comparable wheel.  For example, if you have a 2017 Sport 650B, the page will tell you it has "Shimano Center Lock" hubs and "[Specialized] Stout 650b, alloy, disc-only, double-wall, 25mm inner width" rims.

Note that older years are described as "650B" while from 2018 Specialized is using the term "27.5"; according to Sheldon Brown both of these are designations for (ETRTO) 584mm tires.


Method to remove and prevent rust on a Reynolds 531C bike frame?

That would totally depend on your wishes for this bike. Also it looks like this isn't the only spot that has corroded. On the tube going to the rear axle there are also plenty of darkers spots. They could be dirt, but might as well be rust.
If you want the bike to stay as original as possible I'd suggest to grind down the rust untill shiny bare metal shows, and covering that with some good coats of clear paint. That way you can maintain the most of the original finish. You could alternatively try to find a paint in a matching collor.
If you want the bike to be in the best shape possible it might be wise to completely strip the frame from all paint, and respray it completely. In this case you can use a chemical paintstripper to get rid of the current paintjob, and respray in a color of your liking.


Lowering gears and changing crank length on 1994 Bridgestone MB-5

There are some differences in chainring spacing between crank speed generations. But even within a speed generation, the spacing numbers are not truly standardized. That's one reason for the ambiguity you've found. Another is that with front shifting compatibility considerations on bikes in general, there are a lot of things one can do that fall under the category of setups that can be made to work but possibly with some level of compromised performance. Some voices you're likely encountering would think little of giving all those setups a stamp of approval. Others, such as those of us who do this for a living, tend to operate more in the realm of asking what will perform optimally or as-designed and disregarding everything else, because if we don't we're going to let people down and/or waste a bunch of time.

All that said, dropping in a 9 speed triple crank on a seven speed bike with a 7/8 speed chain and front derailleur is generally fine. So if 165 with a 22t small ring is what you want and you can find it in 9-speed, go for it. If it's another square taper crank, make sure to get a new BB of the correct spindle length unless it happens to use the same as what you've got. I recommend having some .6mm Wheels Mfg chainring spacers to tune things if needed, i.e. enough to put them under both the large and small ring to slightly increase the spacing if you find that your existing shifter and FD are producing too much total throw.

Also, in case it's helpful, 104/64 is the predominant modern MTB triple BCD. The smallest ring size the 64mm can take is 22t. One spendy but not all that difficult way you could go would be getting one of the various fancy interchangeable spider cranks, most of which come in 165 and have or have had 104/64 spiders available.


Yes, Cane Creek makes a headset bottom for exactly this problem. I've used it on my MTB and it has worked just fine for over year. It does require that the original frame use zero stack or interior headset. But it looks like yours does.

Note: in the general case with a true 1-1/8" ( i.e. 34mm interior diameter, exterior headset cups), there isn't enough interior space to use a tapered fork.

From the Cane Creek Headset FAQ.

Cane Creek was the first headset company to offer a tapered solution for 1-1/8" head-tubes. Called XX-44, this bottom assembly enabled the use of 1-1/8" to 1.5" tapered forks on straight, 44mm head-tubes. This gave consumers more options, and frame designers more flexibility when creating the perfect ride.
Due to the popularity of the design, the EC44/40 (External Cup for 44mm head-tube, 40mm crown race seat) Bottom is now available in both the class-leading 40-Series and the premium 110-Series of headsets. This tapered solution fits 44mm head-tubes only; a "traditional" 1-1/8", 34mm version is not available.
Please note: Nominal insertion bore depth for 44mm head-tubes is 9mm. EC44/40 requires an insertion depth of 15mm. Park Tool Reamer 788 should be used with the supplied spacer to reach the 15mm bore depth for EC44/40 Bottoms.


Best Gearing for a very fit but on his way out 52 year old

I use Sheldon Brown's Gear Calculator whenever I'm looking into gear ratios. For someone who doesn't ride any big hills I would think that 50/34 - 12/28 would be absolutely ideal. You could go 1x and get 98% of a 50/34 with a 44+10/42. See SRAMs pocket guide

50-12 tops out at about 33mph definitely not something that mortals can sustain for very long on a flat road.


Your basic bicycle hub is simple yet complex:

At each end there are bearings, either loose balls or a set of balls in a "cage".  They fit into the "cup" recess in the end of the hub body, then the "cone" is screwed onto the axle shaft to hold everything together.  A "lock nut" tightens against the cone to keep things from working apart.  (Note that this lock nut is different from the nut used to secure the axle to the frame.)

Adjusting an axle involves screwing one of the cones in or out as needed to achieve smooth motion with neither looseness nor a sort of drag and rough feeling (when the axle is spun by hand).  Then the lock nut must be tightened against the cone.

In order to do this adjustment one needs a "cone wrench", an inexpensive, non-adjustable open-end wrench that is very thin.  These are available online or from any bike shop that sells tools.  (Alas, there are several sizes, and you need to find the right size for your axle.)  The cone wrench must be used to hold the cone while the lock nut is tightened against it.

This adjustment is apt to take 3-4 tries to get it right the first time -- the cone must be very slightly loose before the lock nut is tightened, as doing so pushes the cone in slightly.


Benefits of latex tubes... Are they worth it?

Pros of Latex Tubes
Lightweight compared to butyl tubes
More flexible than butyl tubes, leading to a smoother ride.

Cons of Latex Tubes
More expensive (about 3 to 4 times the price)
May be more susecptable to blowouts.
Should be powedered with talc before installing to reduce stickyness and avoid pinching.
Looses pressure more quickly due to more porus nature, you need to pump before every ride

You'll probably notice a difference using latex tubes only if you are running higher TPI road tires. A higher TPI tire (100TPI+) is going to be thinner, more flexible, lighter, and have lower rolling resistance than a low TPI tire. The Latex tube will help when using these tires, since it's flexiblilty will compliment the flexibility of the tire.  Ultimately, this will give a 'smoother' ride because the tire will be able to conform better to the shape of the pavement and be very light. A standard butyl tube would add more rigidity to the flexible tire, reducing the benefits of the more flexible outer casing.

However, if you have a very rigid tire, then it will not have as pronounced effect, in this case, you're probably not going to care much about the difference in tubes. So if that's the case, just run standard butyl tubes, because you won't notice much of a difference.

From what I can tell, You can mend punctures easily with ordinary patches and glue. Sheldon Brown recommends using a piece of old latex tube cut in to a rounded shape and attaching it with tubular rim glue (regular vulcanizing fluid from a patch kit can be used but does not work as well)

If you already have nice tires, and a smoother ride and weight savings are important to you then it may be worth checking out latex tubes.


It looks a lot like this 1998 Zephyr Boardwalk 6

BikePedia
The Boardwalk also came in a single speed. Both bikes came in men's and ladies models.
Sorry about the bad picture, I looked for better ones.
The "Zephyr" brand was also used to on BMX bicycles.
On the linked BMX bike the logo is similar and there is a "MANUFACTURED EXCLUSIVELY FOR S.B.S INC. SEATTLE WA" sticker.
If the BMX Museum is accurate the BMX bikes were made between 1985 and 1999
Interestingly there is also a "Torker Boardwalk 6" cruiser which looks a lot like the Zephyr. It turns out that:

In 1984, the Torker Bicycle Company went bankrupt, and Seattle Bike Supply purchased the name.
Wikipedia


Can you record multiple rides on a Garmin 500 and download more than one on Strava?

Can you record multiple rides on Garmin 500

Yes you can record as many rides as there is room on the internal memory. Once you have completed a ride hit stop, then hold the lap/reset button for 3 seconds to get the unit to save the ride and reset the screen.  This will save the ride as a .fit file on the unit (Figure 1).

The Garmin 500 is an older unit with less memory, but right now I have 124 rides on my Garmin 500 dating back to Nov 2018 and there is still plenty of room left.

  then download them sequencially onto strava

You will need to connect the Garmin unit to a compatible computer using the supplied USB cable, it will typically mount as an external drive (Figure 1). From there you can manually upload the .fit files to Strava using their file upload feature.

Alternatively you can install Garmin Express on your computer, which will automatically upload the .fit files to Garmin Connect when you connect the your Garmin 500 to your computer.  Strava can then be set up to connect and download activities from Garmin Connect.

Personally, I just do it old school (file upload).

Figure 1. Location of Garmin 500 activity files.


Difference between Shimano GRX400 and SRAM Apex

SRAM Apex comes in 1x11, Shimano GRX 400 is 1x10 or 2x10.

SRAM uses the small shift lever for both up and downshifts. On Shimano system the whole brake lever moves inward and is used for downshifts on the rear and up shifts on the front Personally I prefer the Shimano system as it makes it easier to downshift while braking and give more authority to up shifting at the front.

SRAM shift levers have a far more positive click to them. SRAM uses DOT fluid in hydraulic brakes whereas Shimano uses mineral oil which I think is a bit cheaper.

The best thing to do is test ride some bikes and see how you feel with the operation of the shifters. Also pay attention to whether you want a 1x or 2x system. 2x systems give you smaller jumps between gear ratios and a wider overall range.


Replace a 2.0" tyre with a 2.1" studded one?

Look at what clearance between the tire and the frame do you have now. Often the tightest place is the bottom stays.

Changing 2.0" to 2.1" increases the tire diameter by about 2.5mm ("about", because the rim width stays the same and does not proportionally increase), i.e. the tire grows ~2.5mm upwards and ~1.3mm on each side. Not all tires are measured equally, some "2.1" tires may be wider than others, so add one millimeter more to be on the safe side. Besides that, knobs make the tire higher, attempt to account for that too.

If you conclude that there is enough space to fit the wider and knobbier tire, there are no other obstacles to replacement.

(Not directly related to the question, but I'd strongly recommend buying higher-quality studded tires. This is an item which brings much more value for the money than any other bike part.)


I manage the workshop in one of the busier shops in the world.  There is not, to my knowledge, any way to obtain cork or neoprene bar tape which is not pre-cut to length.  Usually, in my experience, though, one roll is enough to do both sides of a bullhorn bar.


Freewheel threading on Miche flip-flop hub

I have these hubs, I used a normal freewheel (1.37" x 24TPI) I had lying around from my old single speed build.
I'm 99% sure you also need a normal single speed / BMX / trials freehub. The 1% doubt I have is, that I don't know which model/year your hub is. And I don't know if they ever did a different one.
Worst come to worst, buy a freehub from a place which does refunds easily. That way, you can try to fit the freehub and if it doesn't fit, just get your money back.


Next to the M and L, it lists 65"-70", and 68.5"-75". " is an abbreviation for inches. So at 5'8" (5 feet 8 inches), or 68 inches, the M is probably a better fit, but if the rider is still growing, you might get the large because it's so close.

That said, it seems to be a very expensive bike to be buying without a test ride first, even more so when you are on the border between sizes. I'd suggest looking at something locally if that's an option, or at least something with plenty of good reviews if you can't buy locally.


How do I install drop bars on my trek earl?

Bars of the correct diameter and new brakes.  But since that frame was designed for flat bars drop bars will put you really low.


Cable routing and why is there no optimum solution

What are the reasons of the other cabling schemes?

Most Cyclocross bikes will route all the rear cables along the top of the top tube. In a cyclocross race, you will get off and shoulder your bike, the cables would get in the way on the underside of the top tube. Many CX bikes have a flat bottom top tube as well for easier shouldering. Routing the cables along the top keep them cleaner too, cyclocross races get muddy and if they put the cables on the bottom of the downtube, they would get very wet, muddy and allow grime into the housing.


I actually use that hub quite a bit, and was just looking into that setting for one of my customers earlier.  The "set" gear is 2.  set the shifter in 2, then yes, you want the connection from the chain to pin to be just protruding from the axle.  Once you set it like that once, lift the back wheel off the ground and pedal it one revolution forward and pedal it backwards to engage the brake once just to be sure it's engaged in the gear, and check it again.  If it has "settled into gear" and the position of that pin has changed, set it again.

Once you get it so in gear 2 the pin has stayed at that point, you should be good.  Check that all gears are working, and that it isn't slipping like you said in your original post.  Riding it for long periods of time with it slipping out of gear will wear out the internals very quickly.


I expect that after 10,000 km your chainring also needs to be replaced (frankly, I find it astonishing that you made it that far without replacing anything else.  That's amazing.).  Am I correct in guessing that you spend most of your time in your middle chainring?  If so, it will be significantly more worn than your large or small rings, which would explain why you're only experiencing slippage in that ring.

It should be very easy to tell if it needs to be replaced--either take it to your shop and have them look at it, or look at it yourself.  Worn chainrings will show a characteristic "shark fin" on the teeth if they're worn too badly.


Can't do outdoor training for 150km and only on trainer. Can anyone give tips and training plan?

Should be possible, but you are going to need a lot of dedication to sitting for hours on the trainer. You'll also need to put a trainer specific or cheap disposable tire on you bike as trainers wear rear tires fast.

The training you need to do depends on what your level of fitness is, the max distance you can currently ride and the nature of the 180km event (flat or lots of hills) and how you want to ride it (target average speed, how long you plan to take overall, number of stops etc.)

It will be easy to search for and build a training plan with 30-60 minute sessions 3-4 times a week that will increase your overall fitness and strength substantially. This should be your initial priority.

The difficulty will replicating the duration and nature of the long ride. I would not try to replicate the distance of the ride on the trainer, but instead the duration and intensity. Estimate the time duration you will take for the event and plan sessions on the trainer working up to about 75% of that, at your planned intensity.


Repairing a twisted front rim in emergency?

It is a professional's job to true and tension a wheel. One worth learning to do for yourself, but not one to jump into without knowledge and the proper tools. No it is not easy to do on the road, except as an emergency " get you home" fix. Very likely, a amateur attempt to fix it on the road will result in more damage.

In addition, a "somewhat twisted" rim from riding without a tube for an extended period usually indicates a problem with the metal of the rim being physically bent. In order to true a wheel, you add tension to each spoke until the rim is straight and the wheel is round under high tension. But if the wheel doesn't start straight, the spokes will not be tensioned evenly, and the job will not last for more than a few hours, or days if you are lucky. It requires skill, and quality tools, or you will make the damage worse. I would suggest in the future, walking the bike om, rather than risking this kind of permanent damage.

If you have disc brakes, you may be able to run different sized wheels in the bike for an emergency, but it will change how the bike handles, and may affect the safety of riding the bike.

If your bike has brakes that grab the rim to stop, then you must use the original size rim to replace it, because otherwise you will have no brakes.


BMZ presumably stands for Biemmezeta, an Italian manufacturer from near Milan who did a lot of contract manufacturing for a lot of places (e.g. Performance Cycles) as well as sold bicycles under their own brand. More details on your location may help narrow down the bike's pedigree.

As Daniel R Hicks estimates the date of the bike in the comments, it should be noted that BMZ was popular in the 1980s.


What is the purpose of suspension lockout?

You turn it on when riding on smooth surfaces or going up hill to improve pedal efficiency.  It's hard to know if you will need it in advance because without riding the bike you won't know how well the suspension design handles pedal bob (the energy lost by the bike suspension compressing under pedal forces), try and get a test ride.


Steel makes for a heavier rim; the modern-box section design works well for taking advantage of aluminum's lower density.  Furthermore, since steel will rust, the rims are typically chrome-plated.  The chrome plating makes rim brakes almost useless in the wet, which is exacerbated by the poor pads used on most of the classic bikes that shipped with steel wheels. In contrast, steel rims are almost indestructible - they can be bent out of shape and re-bent repeatedly and will wear much longer than aluminum rims.

As far as your specific case, many older bike-boom era bicycles were built with "Schwinn"-sized wheels, ISO 590 or ISO 597, both labeled as 26 x 1 3/8".  As far as I know no manufacturer makes aluminum rims in that size, so finding a replacement wheel for an older bike usually means either getting new brakes and converting it to a modern size (ISO 559 or ISO 584) or finding an old wheel that's not too beat up.  The latter is usually pretty easy, cheap bikes ship with steel wheels that are often simply discarded.


Do tires with worn sidewalls need to be replaced?

Yep, that tire needs to be replaced.  (It appears that either it's been run underinflated or you've been using your foot on the side of the tire to brake a lot.)


Why would my rear brake pads wear faster than front?

There are a couple of factors that might come into play.

The first is that you may be braking more than you think at the back. Which brake is controlled by your stronger hand? Are they adjusted the same?

The second factor is dirt. The front wheel throws up dust and muddy water, some of which can reach the back wheel even with mudguards. This can abrade both the pads and the rims. This will be much reduced on disk brakes.

If you use the brakes a lot downhill you may find yourself using the back lightly to stop yourself accelerating. This seems to cause quite a lot of wear, perhaps because the brakes don't remove the dirt like they would in a hard stop and perhaps because it's a lot of wheel revs with the brake touching the rims.

I used to notice this on stock pads and the cheap dual compounds I first replaced them with. The KoolStop pads I now use wear much less and I don't notice a difference. This is on ordinary shimano V brakes. This was despite only taking up the slack in the back brake when coming to a hard stop, but I had a couple of steep downhills.


You need a mountain bike specific crankset.  Tiagra is a road group.  Road bikes typically have a 68 mm wide bottom bracket shell, and mountain bikes have 73 mm.  The wider BB shell is used to give a proper chainline with the (usually) wider rear axle spacing (OLD) and will result in a wider q-factor (distance between pedals.)  This frame is an unusual build with the 73mm BB and the 130mm OLD, perhaps to take advantage of the smaller chainring sizes available in MTB cranksets.


135 means 135mm rear drop-out spacing - the older standardard for MTBs that is still used on less expensive bikes.

QR is quick release, as opposed to a solid bolt on axle or more modern through axle.

6-bolt refers to the disc mounting standard, the other being Shimano's Center-Lock.

The free hub body width needs to be compatible with 8/9/10 speeds cassettes. You'll obviously need a hub with the same spoke count.


Is it acceptable to mountain bike on narrow hiking trails?(Minnesota)

It depends on the local laws, both regional and countrywide. It's not really a question of acceptable or not.

e.g In England trails can be strictly footpath which means no bikes. Bridleways, Byeways and Byeways Open to All Traffic (BOATs) can be ridden by bike with pedestrian priority.

Find out the local laws for your region.

If you do find that all your local trails are fair game it's still up to you to ride in control and with courtesy. Any person & bike collision will be your fault.


Paint it with fluorescent paint and then illuminate with ultraviolet lights (and white LEDs serve this purpose fairly well).

There are also glow strips/panels sold mostly to (oddly) computer hackers who like to light up the inside of their computers.  And probably a few other specialty markets.

Of course, you'd have to rig up some sort of power supply.  Batteries can be concealed under the seat or in the seat tube, or on the person of the cyclist.

[Odds are, to achieve this special effect for the commercial, the bike was painted with fluorescent paint and then illuminated for several minutes with separate UV lights.  The paint will continue to glow brightly for several minutes after being so "charged", long enough to shoot the commercial, I'd guess.]


How much clearance do you have on the front wheel? Doesn’t look like you can fit much more than 25mm width there. With your weight and luggage I’d go as wide as possible. Maybe 25mm in the front and 28mm in the back (if the brake has enough clearance).

Of course it also depends on the quality of the roads.


Buying new thru axle road wheels - What do I need to know?

When getting the same 142x12 and 100x12 standard wheels I advise to take note of the following:

If your frame requires special dishing or not. Synapse probably doesn't.
Outer rim width. With wider rims, the rim clearance might become an issue. Not your case, though.
Rotor fitting standard, 6 bolt or centerlock.
Freehub body, 10-speed or 11-speed HG, Campagnolo or whatever comes out next (SRAM XDR, Shimano Micro Spline).


Riding packed limestone trails on 700x23 ties

You may want to go up to 700x25s or 700x28s. While you should be okay with 23s, you'll definitely have greater peace of mind with a thicker tire. You may also want to drop the pressure slightly to 80–90psi.


The same way you would for any paint: find a swatch that matches it, or chip a bit off the bike, and then take it to a paint store and ask them to match it for you.  If it's a modern bike of a decent manufacturer you could always drop them an email, and they might be able to give you the make and model of the actual paint they use.

Also remember you will have to lacquer it afterwards, and that has an impact on it's final look.


Is it possible to fit this Tioga Mc Groove saddle on my bicycle?

Yes, your bike can be fitted with pretty much any saddle.

The (metric) allen key on your new saddle is a 6mm. If you're using Standard Allen wrenches its probably a little larger than 7/32".

The seat post needs to fit your frame. So you will need to mount the new saddle on your old post, or buy a new post that exactly matches the size from your original one.

It does sound like you've disassembled the guts of your suspension seat post, so if you can't get it back together, you're probably looking at a new seat post.

There should be no problem mounting that seat on any post that fits your frame.

I hope that helps.


Are MIPS helmets compatible with helmet mount lights or cameras?

Yes... and no.. technically they are. While MIPS uses a slip plane, it is not going to roll around all willy nilly with every head movement. It takes a lot of force to get it to move, as it is suppose to. Nor should you ride while making bobble-head like movements anyway :P
Many new helmets come with a either built in or removable camera/light mount that have MIPS technology... The Giro Montaro for example is a MIPS helmet that boasts full accessory compatibility as well as many other that do.
However..
The kicker is - Having a camera or light mounted may prevent the MIPS from doing what it is suppose to.

Vents are necessary, but make sure they are smoothly faired into the helmet shell, and avoid any helmet with unnecessary fashion ridges on the outside, or snaps for visors, or any other feature that could cause the shell to snag. This is an easy item for a consumer to assess, as long as you keep in mind that you want your head to slide on impact. It should be evident that you don't want to add any accessory or cover to the exterior of a helmet that adds to its sliding resistance. That includes lights and cameras. Many of the ones we see have mounts that are much too strong to break away easily when you need to slide. ASTM is developing a standard for the force that should trigger an accessory to break away. Bell already has its own internal standard. In the meantime you are on your own to figure it out.

Sourced from: BHSI
Basically if you don't want to read that, mips prevents your head from catching and rolling your neck in layman's terms. So that the helmet rotates rather than you neck. Having a large camera or light on top can catch on the ground and prevent it from doing what it is made to do. So while they are advertised as being compatible, what they don't tell you is in the event of a crash, accessories may be what causes injury and prevents the MIPS from moving correctly.
Also that link is a good source of information on MIPS technology in general and points out a lot of flaws with the system. A worth while read if you have a few minutes.


Advice for servicing a Scott Sub 10 [8 speed Alfine hub gear]

I've owned a Scott Sub 10 Alfine 8 (orange 2011) since Jan 2012. I've done 1600 miles and it runs very nicely indeed. Unfortunately I rode through a 'puddle' during the floods, which turned out to be 18" deep - it completely submerged the hub for 5-10 seconds. I bought a litre of the magic shimano oil for £60 from a shop which has since gone bust. When I opened the hub there was absolutely no water ingress and the internals looked factory fresh. I followed Shimano's servicing instructions to the letter. It's not difficult, taking about 2 hrs - a professional mechanic could do the whole thing in 30 mins.
The quote of £140 is very steep. Although the oil retails for £80, it is reusable - just leave it to settle and return to the tin. I weighed the oil can before and after, and I used 35gm - in other words there's enough for 30 services. The cost to a shop which regularly services Alfines would be £3 per hub. Adding 1 hour's labour would come to about £30. If you do your own servicing, don't degrease the hub in solvent - the drive side bearings are inaccessable without buying an expensive tool, and thin oil, like ATF, will not keep them sweet for long. Read the net for loads of people who've done this and now blame Shimano. Regarding 8th gear: this has the most cable tension,so if it's an adjustment problem, it needs more tension. Also look out for a rusty/ bent cable. Finally, if there's dirt behind the casette joint it might limit movement.
Try removing the cassette joint, cleaning it and regreasing the cable while your at it. I'd be quite happy to talk you through the service, but I don't want to publish my email/phone. I'll keep an eye on this page incase you want to contact me again.


What can/would you upgrade a SRAM GXP BB to?

The SRAM Apex crank requires a GXP design bottom bracket., i.e. 24mm drive side and 22mm non drive side. That's not something you can change.
The GXP design is generally reckoned to be inferior to Shimano's Hollowtech II design because the non-drive side bearing floats and is not pre-loaded, unlike Hollowtech II where both bearings are pre-loaded. Source: Hambini YouTube Channel Caution! Lots of swearing and cussing.
However, you could look for a product with higher quality bearings than SRAM offers. There are several 3rd party manufacturers that make GXP compatible bottom brackets. Wheels Manufacturing for example.
You should also check the alignment of the threads in you bottom bracket shell. Angular misalignment of the bearings accelerates wear. One way check (at least for gross misalignment) is to remove the crank, then re-install. If the non-drive side end of the axle is not lining up exactly with the non-drive side bearing as the axle is pushed through the shell you have misalignment.


Hydraulic disc brakes - total friction as a function of rotor size

Don't worry about equal torque.  The front wheel will do as much as ninety percent of the work on a maximum stop.  You will learn to modulate the rear to prevent lock-up.  Equal pressure will be fine for normal stops.


How tight should your stem valve nut be?

You don't need the nut, really (and its rather abnormal on Schrader valve tube) -- a lot of people just throw it away.

The point of the nut is so that the tube's stem doesn't go into the rim when you're trying to inflate the tube and the stem doesn't move around when you're trying to pump the tire. Note that the tube can only go significantly into the rim if the stem is very short relative to the rim or the tube has very low pressure -- you won't see its effects when topping up your tires.

If you're using a Presta valve in a Schrader valve rim, they sell specific grommets for a few cents to use to keep the Presta valve secure, though some people install the nut on the inside of the rim to act as the grommet.

If you want to use the nut, inflate and lightly tighten it down after inflation with your fingers (there are some other schools of thought on how to use them, but this is probably the simplest). Don't over tighten it or you'll damage the tube.


I'm not sure about UK-specific swap service, but here are a couple of things you can try:

Check with your local bike shops and see if they have loaner saddles. My fave local bike shop has loaners of almost every saddle they carry and a sign out ledger. You can sign out the saddle and leave your credit card info. If it's not returned within a couple weeks, they bill you for the full price.
Buy a saddle you're interested in, and carefully wrap a long strip of electrical tape around the saddle rails. The rails are thing enough that the width of the tape can pretty much go around. Then clamp them just firm enough to stay in place, and you'll find that after removing the tape, there are no marks. Voila, you can return it according to the return policy of most shops ("no marks on rails"). If the saddle comes zip-tied into a cardboard backing or box, just buy some dollar store zip ties of the same color to put it back in. I've done this with great success. Just make sure not to lean it against a brick wall or ride in your retro 70s punk studded leather bike shorts.
Check your local bike forums/ club scene and see if anyone is willing to loan out a saddle you're interested in for a few days/ weeks (offer them a safety deposit).


Can I upgrade a Hercules Dirtrider 26" with gears and a disk brake?

The derailer is sort of the easy part. Your frame could take a claw style derailer like this:

Or you get one of these and have a lot more options:

120mm is the minimum rear spacing for derailer multi-speed rear hubs, so you would probably need to spread (bend) the frame.

You'll also need a new rear wheel, chain, and freewheel. Your cranks will probably not give workable chainline with a multispeed freewheel as they are now, which usually means toying with the BB spindle length, which is a pain on cottered cranks, and would probably also have you either removing the chain guard or finding a way of spacing it out.


Yes. I own a north st bags convertible pannier and think it works great.  It hangs a bit low, so don't try and use it on low rider racks.

http://northstbags.com/products/woodward

Also see Richard Jones Convertible Backpack

http://www.convertiblebackpacks.us/

Also try WOHO bags "NINJA NINJA" convertible backpack:

http://www.wohobike.com/product.php?linkid=133


160mm crank is abnormally short. This doesn't mean that you shouldn't but as Axemasta mentions, you should have a bike fit before deciding what crank arm length you should have. Plus you've not given any details about your bike or it's size.

There are so many variables involved in knee pain, it would be foolish for anyone to suggest your first course of action to be crank arm length.

Bikes related variables for knee pain:

Overall wrong size frame
Bad saddle position (tilt and position on rail)
Stem too long
Handle tilt
Crank length
Pedal choice / fit

Body related variables for knee pain:

Incorrect cycling technique
Muscle imbalance
Muscle tightness
Non-optimal nutrition

These are just examples of a much larger list.

So, in my opinion, without finding the root cause of your issue, buying extremely short cranks should only be done if you are 100% that is what you need. And I don't think (with the information you have given) that will be what you need.


Roller Brakes (a form of drum brake) do need a regular service, which does require grease (yes it does seem weird to grease brakes) as there are some moving parts that can rub. You should be able to buy some Roller Brake grease/oil and apply to the appropriate location. I am not 100% familiar with Roller Brakes, so you may need to check the location in your manual, or perhaps someone else can help out with the description of rubber cover if needed.


You have the sort of headset where the adjustable race consists of a plastic shield fixed to a steel piece that has the bearing surface and the wrench flats. I think it might be a Shimano Exage Sport.

If you have access to the sort of used bike/parts shop that has bins of old stray headset parts, you might be able to find a replacement. But what you've got has never been super common and even then it's only one model, so you might be looking for a while. On the plus side, uppers tend to die last, so you might be able to find an orphaned one someone squirreled away.

Printing a replacement would be pretty reasonable here too, if you're into that kind of thing. You could saw it in half through the the middle to get the cross section and then lay that on a scanner, and from there make up a new plastic seal part in Fusion 360 or whatever you like and snap it onto the existing bearing race part.

Probably the most reasonable thing is to just replace the headset, or even just the upper.


How to check for aged/deteriorated weel rims

The wheel should run true

radially (up/down)
axially (sideways)
and should not be twisted (as each spoke applies force at its eyelet, a weakened rim might twist, and this twist might not be noticed whilst truing out axial deflections).

The form of the bead interface should be consistent, no dents in any direction (unless the rim is for tubular "stick-on" tyres, in which case it would not have a bead seat).

If the rim has a braking surface, it may have featured wear indicators. These would be either square-edged grooves or cylindrical indents.

If the braking surface has become concave, the rim wall connecting the bead interface to the well of the rim (where the spokes end) might be dangerously thin. A failure here would be characterised by a sudden separation of a metallic ribbon as the bead interface succumbs to the force applied by the tyre pressure, and the tube would expand through this new opening until the tension in the rubber exceeds its strength or the sharp edges of the broken metal pierce the tube.

The metal surrounding each eyelet should not be deformed. A wheel that has been repeatedly trued may have excessive tension on some of its spokes. A wheel with insufficient tension would not distribute loads appropriately as it rolls, causing spoke tension to fall an rise. Changes in tension cause deformation in the rim and spoke. Metals have a finite capacity for load cycles, ending with a fatigue failure.

The rim may tear at an eyelet, allowing the nipple to pull through and causing a sudden change in the tension distribution of the wheel, which may deflect enough to cause contact with the brake or frame. A complete localised loss of tension may also result in a load exceeding the capacity of an unsupported rim section, resulting in a catastrophic failure of the wheel and sudden changes to the trajectory of the rider.


Bladed spokes on drive side, regular on other side

Your first, and possibly best, place to start researching is the Cannondale website.  It appears that 2 models of the Synapse, the Synapse Carbon Disc Ultegra and Synapse Carbon Disc Ultegra DI2 come standard with Mavic Aksium Disc wheels.  You could then refer to the Mavic website to get the specs on those.


Does my chain need to be replaced because it has looped itself many times?

If it's just tangled, untangling it is fine, but if your derailleur has suffered there's a good chance your chain has too, which will weaken the chain. Laying it out on a flat surface, it should look flat once you've taken out the loops.

If you've got twisted links, they're likely to snag on the derailleur or gears, possibly only under load. If you try to straighten them, they'll probably end up stiff, and will be weaker. I recently trashed a rear derailleur and definitely had to replace the chain. Some links were badly twisted, and even with those removed the remaining chain was fragile (I snapped it twice in 5km of gentle riding). One almost new chain in the bin. You may be lucky, or you may be in the same position.


Hydraulics are used on higher end systems, cables are often a sign of a cheap brake set, so your observations are correct regarding "professional" bikes. However there are very good cable disc brakes (e.g. Avid BB7's) that are the exception that proves the rule. .

Cables have the disadvantage of friction that hydraulics virtually eliminate. It is significantly easier to modulate hydraulic brakes, you get more force delivered to the pads, hence more stopping power for the same input, and faster/more reliable and predictable pad retraction when releasing the brakes.
As the Hydraulic system is sealed, grit and grime cannot get in to jam up the moving bits, making them virtually maintenance free (replace worn pads is about all need doing)
Hydraulic systems are also easier to set up and adjust (with the right tools - next to impossible without them). Cables have to the exact length, and need "tweaking" as they stretch from new.

That said - a good quality and well maintained cable system will out perform a poor quality, cheap hydraulic brake set, so you cannot state "Its hydraulic therefore it's better".

Disadvantages of hydraulics occur when you get a leak such as hole in a hose or blown seal. They are less "field serviceable" than cables, essentially the brake is rendered useless and unrepairable (in the field) by a minor fault - which fortunately happens very rarely, and usually caused by poor transport rather than while out riding.

Another reported problem with hydraulics is boiling of fluid. This is more of a problem on road bikes where mountain descents of 100's of vertical meters in a very short time are more common. With overheated fluid initially the pressure in the system stops the fluid boiling. When the brake is released (even for a moment), the pressure comes off and fluid boils, and the brakes no longer work - at all - the lever just goes all the way in. Another thing that can happen is the rider stops with no problems, but the heat in the calliper (no longer being cooled by airflow) migrates to the fluid over the next few minutes, so when the rider rides off there are no brakes.  (This is different to disc fade where the pads and disc overheat and brakes loss effectiveness slowly - both types suffer this equally.)

Watch out in the future for Hydraulic shifters.... Available now if you have the big $$$$, lighter weight than XT and XX level components, almost certainly more reliable and easier to setup.... (Update 2015- Electric shifters mean these will not become main stream.)


What options do I have when replacing my fork's elastomers?

I had an elastomer suspension a lot of time ago, and did my own maintenance on the elastomer compartment. I would not take a fork like this and put springs inside. Bike suspension elastomers dampen the motion of the suspension in two ways:

They expand laterally and generate friction against the inner walls of the suspension;
They have a natural visco-elastic mechanical behaviour, that doesn't let the suspension "spring back" too fast.

With springs only (and no dedicated way to control the rebound), the suspension would become too "wild", I'd say.

I think you should take any elastomer kit that fits inside your suspension, with enough lateral clearance, and use it, no fear. Micro-cellular urethane (MCU) was the topmost material used in bike suspension elastomer (before becoming almost obsolete).

It is important, too, that you put them inside the fork with lots of grease, and specifically LITHIUM-FREE GREASE, so that they don't chemically react with one other. Most probably, there are specific suspension greases in bike shops.

Hope this helps


Bicycle Repair Stand Solutions for bikes with a Dropper style seatpost

In my opinion the dust hasn't really settled on what the best practice is for putting bikes with droppers in the stand. But I work on them frequently and here's what I do:

Never clamp the upper with any clamp, because any scratches or other surface damage (surface imperfections, really) can have a deleterious effect on the wiper seal, either wearing it or making it less effective. I just don't do it because I don't feel there's a way to get the chance of damage reasonably close to zero for my liking. It is true that by cleaning everything and using a clean rag around the clamp pads, it will probably be fine. An important point here is that dropper uppers are smaller tubes than clamps are sized to clamp well to begin with, and then they're polished and coated with friction-reducing materials, for the net effect that especially once you have a rag in there, the bike will tend to want to twist in the stand constantly, which in addition to being annoying is how scratches happen.
Some might argue that being a bike part in use is not hazard-free anyway, and so worrying about scratching the upper having taken reasonable precautions is splitting hairs, and that is pretty reasonable in many contexts. But for those of us who work on either peoples' bikes for money, the goal really should be doing zero harm, plus having the bike twist easily in the stand all day is fairly untenable.

I'm willing to clamp gently around the collars of most internal droppers, especially the more OEM-y ones. The connection this makes is kind of wobbly and annoying also, but I don't think you're going to hurt anything doing this. On external posts, the cable will usually be in the way too much.

I think it's basically fine to hang bikes by the saddle on droppers if, and only if, the post is fully extended, but you have to be very judicious about this. Breaking this rule can draw air in to the post and cause real problems, and on that basis one could make the argument to flat out avoid this practice too. Some have already coalesced around this line of thinking, but many of us are just too dependent on the time savings of hooking bikes by the seat for fast repairs, event storage, etc. Reverbs in particular are sensitive to this.

Even though for most cable-actuated posts it hypothetically can be fast and fairly painless to simply remove the post, unhook the little Knarp-like anchor barrel, and put in a surrogate post or an internal clamp, usually it's too much hassle. But in lieu of other alternatives or if you need to totally eliminate any risk to the post or frame, especially if you'll be doing significant work on the bike, this approach has its place.

Usually what I do when the bike will be in the stand for a while is utilize one of the modern screw-down style repair clamps with longer/larger clamp pads, clean and in good condition, to just clamp a frame tube. My favorite for the purpose is the Park Extreme Range Clamp family, but similar ones such as the Feedback/Ultimate clamps are good too. I have a lot of confidence in these to not hurt frames, although you have to use good judgment when doing higher torque operations on the bike. (Again, surrogate posts or internal clamps are what you need if you want to just not worry about damaging anything.)
Another benefit of clamping a frame tube is that you're then able to do work on the dropper itself, ie changing or resizing the cable and housing, with the bike in the stand. The other alternative is having the bike on the ground and bending over it or kneeling. That would be fine if dropper work was only an occasional thing, but it's not anymore, and you need to be able to get into them without hurting your back or crawling around on the ground.

There's a separate discussion here about screw-down versus cam-over styles of clamp, cam-over being the more traditional type.
Cam type clamps by nature expose the frame tube to quite a bit more force during clamping than at their final resting position, and are quite hazardous for thinner/carbon frame tubes. Screw-down style clamps are very different and let you use a bare minimum of force. I don't favor the current Park "Professional Micro-Adjust" clamps for this quite as much because of their short clamps, which is great for seatposts but not for frames.

If possible, marking and raising the post and sliding up enough housing to secure it in this position so you can clamp the lower part of the dropper is another option, but this part is quite sensitive to crushing so I don't like doing it with cam type clamps. I think it's generally fine to do it with screw down style clamps and a real bare minimum of pressure, although here I probably wouldn't on a fancier one. With this approach you have to mess around scooting the cable housing back and forth, which is easier on some frames than others. And if the housing was the perfect length before, i.e. no longer than needed to avoid kinks when turning the bars, then you won't be able to turn the bars all the way with the housing scooted up like this, which is a problem if you were planning on on installing new housings or hoses on something else.


Wanting to change from bar end to road shifters

According to answers to this question, Shimano road and MTB had the same cable pull ratios up to 9 speed, but MTB 10 speed cable pull ratios were changed, which means that Shimano 10 speed road and MTB shifter and derailleurs are not compatible. I think that means that the pull ratio was changed for both front and rear derailleurs.

As you suspected you will need to replace front and rear shifters and derailleurs. If you want to keep the triple ring cranks you need a groupset that works with the  48/36/26 triple chainring and the 11-34 cassette. After a bit of searching around I'm sorry to say I think that will not be possible without changing gear ratios.

The only 3x10 Shimano road groupset is the 3x10 Tiagra, but the rear derailleur will accommodate only 20 chainring tooth difference, you need 22; largest rear cassette sprocket size is 32, you need 34. Total capacity is 41, you need at least 45.

If you swapped the smallest chainring to a 30 tooth it might work. I have heard that Shimano derailleurs will work with a large cassette sprocket 2 teeth larger than the specified max. Swapping the cassette and rings to Tiagra native 11-32 50/39/30 will of course work just fine.

Answers to this question indicate that Sram uses the same 1:1 pull ratio for a range of road and MTB groupsets. This page lists the 1:1 pull groupsets and it seems that Apex shifters are compatible with GX, X9, X7 etc. derailleurs. The X9 and X7 groupsets have 3x10 options but unfortunately SRAM offers no 3x road shifter.

If you can replace the crank and chainrings to 2x then you will of course be able to combine Sram Apex shifters with GX or X9 2x10 derailleurs. You would probably want to replace the cassette with an 11-38 or lower to preserve the low gearing.

You are looking at replacing a significant chunk of the bike which you will have to figure out if you want to spend money on. Another possible cheaper option that occurs to me would be to go to a flat bar and fit Deore MTB shifters.


Ursus is a real brand, even though you don't see a lot of them in the US. Most of their current stuff is fairly high-end, but the ones you're showing look pretty basic (and fairly old- by the 90's hubs were mostly cassettes, not freewheels). Should be fine for road riding/ commuting as long as you know how to lace a wheel. Otherwise the cost isn't going to be worth it and you should just get a pre-built wheel or wheelset.


Why does pedalling backwards not move my bike backwards?

Do you hear a "tick" sound every time you spin the wheel anti-clockwise? that's the freewheel mechanism composed by two small parts called "pawls" and when you spin it on that direction, those pawls turn loosely until they find the "dent" in the inner mechanism (the ratchet body), that's when the "tick" sound happens.

When you ride your bike, those two pawls do exactly the opposite, they catch the "dents" and force the inner mechanism to rotate! it's wonderfully ingenious and simple at the same time.

I've disassembled and assembled several and it amazes me every time.


Croozer bike trailer optimalisation for less tire detoriation

My VidaXL yellow/black soft bag trailer wore the tyres due to parachuting effect caused by the empty compartment and top cover letting wind inside. Also the axle retainers were wrong way round promoting too much toe out, I flipped them over and there is some toe-in, that decrease when pulled along. I now leave top cover off empty trailer so wind doesn't drag it down, top cover is placed on floor and used when it is full of cargo. It is also imperitive to angle the hitch downward so the trailer is level or front low which is better, a trailer that planes like a boat also put undue load on tyres. The towing bike is 20x4 fat bike


Replacing 42/52 crankset to 39/52 - will it make a difference?

You asked: will changing the front to e.g. 39/52 setup make a noticable difference?
My answer is an unequivocal 'yes'. If you can however, consider 34 or 36-tooth inner and 50T outer, if you can find chainrings that fit your spider. TA make a large range of chainrings, however new ones will probably cost more than the monetary value of your bike.


You could try padded cycling shorts/pants, but that would add barely a centimetre.
Re-upholstering the saddle with a thicker cushion might help, but could be fiddly.  Adding a block of wood securely between cushion and frame might work too.
Ultimately the most authorative answer will come from the manufacturer.  I suggest you reach out to them and ask.

1-888-660-0868 0730-1800 PST timezone (they are in California, USA)
Email support@addmotor.com with photos, or even a link to this question
https://www.addmotor.com/pages/contact-us has a chat-window

I suspect this is more of an electric motorbike with barely-functional "decorative" pedals, and just there to satisfy legal requirements.  The footrest over the bottom bracket makes it seem like pedaling is not the intent.
If you get an answer, do please post back here to share for other future users who may have similar problems.

Another thought, if you slide yourself backward on the bench then that may give you more leg room, essentially riding it like a crank-forward bike.  Downside here is the handlebars get further away which might not suit your posture.


Are tubeless tyres an upgrade from tubed tyres, or just different?

What if the puncture is not adequately sealed by the sealant? Can I patch a tubeless tyre in a permanent way with a glue-type patch? A permanent repair without a slow leak for inner tubes is easiest when you always carry one spare tube so that you let the glue dry before using the newly patched tube. Unless some major form of technology breakthrough has occurred of which I'm not aware, if a tubeless tyre can be permanently repaired at all (which I suspect won't be the case because of the sealant "slime"), you should always carry one spare tubeless tire with you to let the patch glue dry. Carrying a spare tire takes more space and weight than carrying a spare tube.

No, if the sealant and specific plugs (mentioned in Diado's answer, the same ones that are used for automobiles and motorbikes) fail to seal the hole, but the hole is not extreme, you can just swallow your pride, insert your spare tube, and carry on riding. If the hole is large, you will need a tyre boot in the exactly same way you would need it for a normal inner tube tyre. Then at home, after a good clean, you can indeed use a tube patch or one of the larger tyre-specific one. If the hole required a boot, it may also require some sewing. and then covering by a polyurethane glue and a patch.

What if the cords of the tire are damaged? With a tube-type tire, there is no sealant "slime" so I am certain that an adhesive tire boot will stick to the inside of the tire. However, with tubeless tires, the sealant might make it more difficult to ensure the adhesive tire boot stays in the intended place.

That is unlikely. Quite the opposite, it will make it stick. Or at least be neutral.

So, why should I care about tubeless tires? I see them as a non-repairable solution that harms the use of emergency tire boots and at the same time encourages the rider to cause rim damage.

It is repairable (I repaired several punctures myself) way that makes better riding properties especially off-road (lower pressures) and reduces the number of punctures you have to deal with (no pinched tubes, small thorns are plugged). Small unsealable holes can be plugged without taking the tyre or indeed the wheel off the bike.
Any potential rim damage is the responsibility of each rider, their selection of the tyre pressure and their choice of their riding style.

The user error requires the presence of three conditions: (1) the tire must have a narrow cross section

Pinch flats can also happen with MTBs.

(2) the tire must be underinflated

Low pressures are selected for good riding properties and it is impossible to perform well in certain off-road events (cyclocross, cross-country) with such high pressures an inner tube would require. The other option is a tubular, but that is even more hassle.

(3) the rider must go over a bump at too high speed.

Stones and roots may be hidden by mud, leaves or appear suddenly behind a corner on a trail. Sometimes they cannot be avoided even on a maintained course, less so in unmaintained trails.


Assuming that "barrings" is the portmanteau of "ball + bearing"....

Harris Cyclery says that most (classic, i.e., non-cartridge) headsets use 5/32" bearings, with 3/16" being rarer. Since bearings are so cheap (US$6-8 for a box of 25-75) you could buy both sizes and see which fits better and use the remainder to overhaul your pedals or hubs, as appropriate. Or take an old bearing if you have one to your local bike shop and have them measure it with their micrometer.

Harris Cyclery also warns you not to  mix and match old and new bearings -- you should replace them as an entire batch. This is because old bearings will be slightly worn smaller than new ones and using mismatched sizes is a sure way to cause pitted races.

p.s. I hate American customary sizes. The nice thing about cartridge bearings is that most of them are metric.

p.p.s. Beautiful bike. It should restore quite nicely.


Why/How should I bed in disc brake pads?

Bedding in brakes removes any glaze from your new pads, and any contamination from your disc rotors. It also transfers material from the pads onto the rotors, which helps them work together. It's essential to get the optimum performance from your brakes when you change pads. Follow these steps:

Clean your rotors - you don't want them to transfer any grease and
grime to your new pads. You can buy dedicated brake cleaner.
Fit the new pads and find a place where you can build up a bit of speed. A hill is helpful for this.
Build up some speed and then brake to a gradual halt. Repeat a few times.

That's probably all you need to do. However some people, myself included, like to pour water  over the hot brakes. I'm not sure this actually improves anything but even if it doesn't it sizzles and steams, which is pretty cool


This is a slightly fringe topic that will draw some blank stares at many cable-selling establishments.

Common shift cables come in 1.2mm and 1.1mm thicknesses for the cable part. SRAM (and I believe Sachs before them) specs 1.1mm for all Gripshift models. Shimano and most other companies use 1.2mm.

The difference of course is tiny. It's negligible in most cases, and a lot of people aren't aware it even exists. Nevertheless, the notion is out there that SRAM Gripshift can have issues with binding or excess friction due to internal clearances if a 1.2mm is used. Personally I haven't experimented much with using the technically wrong thing so I won't speak to how much difference it actually makes and when.

Many third party cables are 1.1mm for maximum compatibility, but not all. There are no disadvantages to using a 1.1mm in a Shimano shifter. Also Shimano Revoshifts, sometimes colloquially called Gripshifts, use 1.2mm without issue, like all Shimano shifters.

If you want to keep it simple just buy any uncoated SRAM cable (I just noticed they list their coated ones as 1.2mm). Many brands won't say whether they're 1.1mm or 1.2mm on the package. But it's very likely a marginal difference if any regardless. Gripshift is the only context where I've ever heard talk of it mattering.

Shift housing manufacturers do not typically list any compatibility distinction between 1.1mm and 1.2mm cables.


Shimano MTB levers with Shimano flat mount road disk brakes (hydraulic)

Yeah you can do that. Just make sure you use a new olive and insert pin.

I have seen it done on a self build frame of a guy as the wanted to integrate the brake as much as possible in the rear. You can follow the link and use and use a translator as it is in german.

https://www.mtb-news.de/news/2018/12/20/bike-der-woche-suit-1-eigenbau/


In my experience, that sound is caused, not by the hub, but because the tire is rubbing against the brake pads. This can happen if the tire is slightly out of alignment or isn't properly trued, or if the brakes got accidentally bumped while riding (depending on your type of brakes). Try spinning your tire and watching it move between the brake pads, and you should see some wobble to it.

If this is the case, try removing the wheel and putting it back on (spin it again before tightening it in, and adjust it accordingly). If that doesn't do enough, try adjusting the brake pads (a different procedure depending on what type of brakes you have, so I can't really elaborate). If it's still giving you trouble, then the wheel is misshapen, and needs to be re-trued, which is probably best done by a bike shop, but isn't too hard to figure out on your own.


What is the difference between 9sp and 10/11sp cranks/chainrings?

8, 9, 10 and 11 speed chains are progressively narrower to accommodate the necessary closer spacing of sprockets in the cassette. The distance between the inner plates is the same, but the width of the outer plates and rivets is different.
The main difference between crank sets designed for 8, 9, 10 and 11 speed chains is the chainring spacing as you have guessed.


I think @freiheit already said it: paint the outside of the outer links!

If you ride single/fixed, this part of the links never touch anything else, so the paint does not wear out neither damage other working parts.

I would do it degreasing the chain very well (boiling with soap in the end, perhaps) and then using a hard foam paint roller, with the chain over the ground with its side facing up.

If you don't mind paying for the job, most the colored chains I've seen in google seem to be powder-coated (electrostatic) or anodized. This would give a probably good result, but I think you wouldn't want to pay the price :oP


Crankarm hitting frame - BB-R60 with GRX 1x11 Hybrid - Gravel conversion

If it's a steel frame, then adding indentation on the left side is a solution, albeit an advanced one that needs to be done with care. A good way to do it at home is use a piece of wood and a rasp/file to create a support form for the inside of the chainstay, tape that to one vise jaw, tape a socket lengthwise to the other vise jaw, and squish. The way they do it at factories is not particularly any more sophisticated. A good rule of thumb type minimum gap to avoid rub under load is 3mm, so in other words you're doing 2mm to eliminate the interference and then another 3 to accomodate flex. Measure the frame OLD beforehand and then if it changes, align the frame afterward with a 2x4 and string. Standard caution that yes you can destroy the bike doing this kind of thing.
If it's not a steel frame there is no solution.
There are no spacer tricks you can play with Shimano road cranks because you can't compromise the left side spline engagement by any amount, and certainly not by the amount you would need here to both eliminate the interference and then create the aforementioned gap. Not safe, risks ruining the cranks and/or having the arm fall off etc. The BB is intended to use without any spacers, so there is no swapping or adding spacers to offset it. (In other words, yes you could create clearance by adding spacers under the left side cup or on the spindle itself, but there will be inadequate contact surface between the spindle and the crank with any such solution.)


Is it possible to transport many (up to 12) bikes using some sort of auto-trailer?

Where I live it is common for commercial operator to purpose build trailers for carrying bikes such as these.

The other option I have seen is custom bike racks for back of any flatdeck trailer or trucks.

One event here has over 1000 entrants to a relay - they need to transport 1500 bikes on the day, up to 100km..... So it's certainly doable.... I am glad I don't do their logistics planning...


Change in setup to stop handlebars jack knifing

I suspect you just have to get used to the different sensations on the new bike, including is steering geometry, determining how much the wheel has to be turned for a given turn radius.

A different bike from what I'm used to always feels weird at first, particularly when steering. Heck, changing, say, the saddle height by more than an inch on the same bike can feel weird.

Steering is inherently counter-intuitive. After all, to turn right, you briefly steer left (whether consciously or not)!

These fat tires are inflated to low tire pressures, and have a high side wall height. Of course, that is going to affect handling. Anything that affects handling will give you a feeling, to which you react, to which the bike, in turn, reacts, amplifying the surprise.

Steering probably lags a bit on these fat tires compared to narrower ones due to the flexibility they introduce between the road and the rim. Say we are initiating a right turn. The front wheel briefly steers left, inducing a fall to the right which produces the necessary right tilt. At that moment, the steering is supposed to recover to begin turning right. If that recovery lags a little bit due to a squiggly, thick tire, that induced fall will continue a moment longer, leading to a sharper turn than anticipated.

If you feel you're going too sharp into a corner (say, right turn), you might subconsciously straighten the wheel slightly (effectively, making a slight left turn relative to the ongoing right turn). But that will induce a counter-steer that takes the bike tighter into the right turn, which then amplifies the original sensation.


How to choose the right brushless outrunner motor for e-bike project

I assume you're using model RC (car or helicopter) parts. When I built my first e-bike several years ago, I also used similar model RC parts.

The control wire on the bottom of your photo leading from the electronic speed control (ESC) uses standard servo control signals.  If you don't absolutely need the arduino, then you'd control the ESC through a servo tester. These are about $5-15 eurodollars. You'd replace the potentiometer on the top with something easier to control - either a bigger paddle, an on/off button, or to a throttle that has potentiometer outputs (most have hall-outputs, so you have to buy carefully as you also have to match resistance range):

Note that you can control a servo ESC through your arduino. You just need the arduino servo library. I refer to this after talking about the servo tester because it's less fault tolerant (and you still need to find a pot-throttle). You don't want your throttle control to fail-closed - that is, to fail in a way that leaves you at full throttle. With arduino  or any CPU-control, this is a possibility, so you should have an immediate battery cut-off switch that uses a different cut-off mechanism (I.e., a contactor to your main battery) near your controls.

And finally about the motor selection. The tiny little motor you have in your photo only has sufficient power at very high RPMs (thousands of RPM). You'll have to figure out sufficient reduction gearing to get it to wheel speed (which are only a few hundred RPM). That's tough to do in a way that also allows the motor to safely freewheel.

Generally, e-bikes tend to operate at higher voltages (36 volts or more) than RC models (which tend to operate at 6s or 24 volts max). This is because you generally want at least 250 watts of power -- if not 750 or beyond. Higher voltages mean less current for the same power. But it also means you have to select a motor that is wound for as few RPM/volts as you can.

You also have to select your ESC (speed controller) carefully as very few can handle high voltage and high current.

There are more options than when I did my project, but you'll also find that once you price a good brushless motor ($80-120) and a good high-power ESC ($100-150) and the necessary mechanical, electrical, and electronic hacking that you have to do, you're within spitting distance of a ready-made hub-motor or mid-drive motor that are designed specifically for e-bikes and are plug-and-play.

Have fun!


Which cycle is preferable for daily commute to office in India?

I'd suggest that you start with a used bike – perhaps the Indian craigslist would be a place to start. You could observe what people are using for commuter bikes in your area, maybe even talk with some of them, and get some ideas about what sort of bike would be appropriate for you. A used bike will be less expensive and you'll lose less money if you decide to sell it and get another bike once you learn what works for you.

Regarding the bag, 10 km isn't too far, if you've got a backpack start with that. You'll probably find that the pack is hot on your back and you may prefer something else – but for starters any bag that isn't too uncomfortable to ride with will get you started. For myself, I don't like having any kind of bag on my back when I ride, so I use panniers – but I have the luxury of feeling relatively comfortable leaving them on the bike for short stops. If you want to get off you bike and go into a store or office with minimal fussing with the bike I think a messenger bag or backpack would be a better way to go.


Should the laws be amended to allow cyclists to run red lights?

Maybe (or not), at some stop signs: but not at stop lights

This sounds like an opinion question so I'll answer it that way.

I think it would be okay to allow bicycles to roll through stop signs on residential side streets.  After all, a slowly rolling cyclist is likely more aware of their surroundings than a fully stopped motorist.

Busy multi-way stop intersections?  Probably not a good idea.  Here in Ohio at least, motorists have no idea how 4-way stops work.  We cyclists would be killed within a week.

Stop lights, no way.  Stop lights are usually reserved for higher volume roads and treating them as a stop sign would be dangerous.

That's all from a safety standpoint.  From a public image standpoint, I think cyclists should obey all traffic regulations to the letter.  I have seen far too many kamikaze cyclists cutting in front of cars, riding on sidewalks and not signalling turns.  That kind of behavior just fuels anti-cycling sentiment.

Cyclists should share the road, not expect special treatment that could promote motorist backlash.


I just replaced my cassette, do I need replace the 2 month old chain?

If it works great, leave it alone. Measure the chain every few hundred miles and install the new one as soon as the one you have on now is worn beyond spec.

And, when you have a few minutes to spare, read this: http://sheldonbrown.com/chains.htm


That looks like the sort of hole you get from tiny bits of glass working their way through the tyre, then slowly cutting into the tube. I'd check the outside of the tyre for tiny cuts, and the inside for barely-detectable points poking through.

This photo shows the sort of small cuts I'm talking about:

Each of those had a little bit of glass or something in it once, but most of those work their way back out. The problem is that the ones that don't usually work their way in instead. If you poke in there with something like the file shown (a sharpened spoke is what many bike mechanics use) you'll sometimes find a ~2mm or smaller triangle of glass.

When those work through the inside of the tyre they don't punch a hole like a nail does, they slowly cut a little slit as you see above.

The way to avoid this is by going over your tyres every few weeks and digging out those bits of glass.

Note that even very puncture-resistant tyres will suffer this, just less often. I've had Marathon Plus tyres puncture this way, but only once (I use those tyres a lot). This guy had the same problem with tyre liners. Picking the glass out is the only solution.

Echoing @DanielRHicks comment: one annoying possiblity is that you have a little fragment of glass or something loose inside the tyre. So every time you check the tyre you don't find it because it slides around as you rotate the tyre checking it, and every puncture is in a different place. So check for that too.


Is it possible this hub can fit to my 8 speed and 32 spokes?

sprocket spacing between 7 and 8 speed is almost identical therefore 8sp is one sprocket wider than 7sp. For this reason, you can't use a 7speed hub for 8speed sprockets unless you miss one off. you would then also need to ensure the gears are set up safely, so the chain can't be shifted into the spokes.


If you poke around on the web enough, you'll find a "magical" gear ratio calculator somewhere. You input the length from BB to dropout and it spits out the
front/back combos that will work w/o a tensioner.

Try this one.

http://eehouse.org/fixin/fixmeup.php

It would be much simpler to change the front chainring, if you can find a magical
combo that matches what you want for a gear. There are also "half links" available that allow you to tweak the chain by less than a full 1 inch link pair.

FWIW, a single speed bike means your almost always in the "wrong" gear. Any change you make will only change when you're in the wrong gear, not the amount of time you spend in the wrong gear. If you're not happy being in the wrong gear, just buy a derailler and a shifter.


What inner tube size to get for my road bike?

As long as it is in the range you are good.  You can even cheat outside the stated range a bit.  Too big and you can fold.  Too small and you stretch.  If it is spare you are going to carry on the bike then the smaller.


What should I consider when looking at a recumbent trike for commuting and winter riding?

I've commuted in the pacific northwest for two winters, and have equiped my bicycles with snow tires, mudflap extensions, and sewn bright yellow waterproof blankets to cover up my Xtracycle deck. A lot of my inspiration has come from the Winter Riding forum on bikeforums.net. I cannot provide model information, but possibly these some areas to consider:

are you considering a recumbent orientation because of chronic back or neck problems?
A recumbent position might actually reduce core strength, or it might place stress on the wrong part of your back
storage and transfer at home and destination: do you want your trike stored curbside in all weather? Trikes are slow to fold, unwieldly to carry, probably more difficult to maneuver up stairways or elevators, and...like cargo bikes, not intended to be put on a bus...or maybe even trains
orient your budget towards all the gear you will want to outfit your trike with for wet weather commuting, plus ice plus snow. Studs are important for ice, studs don't help with snow, fenders don't help with snow, but you want them for anything wetter than slush
visibility: flags, extra blinkers
commuting plus cargo? Consider aluminum "Pelican" cases for secure alternatives to panniers
recumbent seats in wet weather often need to be covered with trash bags because the ones with foam pads become sponges
snow and trikes is much higher friction than snow and bikes. General wisdom for up to 7" of powder is thinner tires (19-23mm) cuts thru powder with the least friction
clearance: if you have mobiliy issues, a higher trike will be easier to mount and dismount; if you do trails or want to clear snow mounds, clearance will help. This might dictate your tire size.
maintenance and support: some trikes come with rear suspension (springs or shocks) and those, like on MTBs, wear out and can be degreased in the rain; many bike shops do not want to support recumbents because its a fringe market and their suppliers don't stock parts for Catrike, Rans or Sun, you might need to be your own mechanic
try before you buy: I own a  used Rans Tailwind and I commute on it, but it's a hassle to make normal bike parts, like pannier racks, fit on them. I didn't know how many options there were for recumbents and I ended up with an ill-suited commuter: it turns out I wanted a short wheel-base recumbent and possibly a non-foam seat plus a windshield so I wouldn't be so bothered by the rain. If you have a local 'bent dealer that can help you setup different models with a wet weather loadout, you'll likely find a quality model that suits you
attachment points: can you attach extra battery pack and lamps for an extended lighting system, computer/iphone/gps unit
electric boost opion: Lightfoot cycles is an example of a 'bent manufacturer that does recumbent e-assist bikes, there are others. If you have significant hills to climb and you're used to standing on your bike pedals, that's something a 'bent takes away from you

Best of luck in your adventure finding your future commuter!


Can I fit a 26x3.5 tire on a 26x4.0 rim?

A 26"x3.5 tire should work on any narrow 4" fat bike rim.  That is: 60mm-70mm wide rims.  It might work on an 80mm rim depending on the actual width of the tire. But will definitely not work on a 5" fat bike rim which is 100mm wide.

Surly does not recommend their Black Floyd (listed at 26"x3.8" but actually narrower) road tire for rims wider than 65mm, for comparison.

I tried to find the actual specs for a the rims on a Sondors Fat eBike, but it looks like there are a couple versions.  One comes with 59mm rims, which should work for a smaller tire.  However, the other version (with the 4.9" tires) might have a rim that is too wide for those tires.

The Apache Fatslick http://veetireco.com/listings/fat-tire-apache-fatty-slick/ is the only option I know of a "road" tire for a 5" rim.


Shimano road and mountain shifters use a different cable pull ratio for the front derailer. It can be made to kinda sorta work, but it won't perform right. If you buy any of the currently made Shimano road triple FDs, you will run into the problem that their minimum tooth difference between the middle and large ring spec is 11 or more, whereas you need 10, and also the profile of the cage won't be ideally matched to your chainrings. The best solution is getting an IRD Alpina FD, presuming you definitely want to stay with your current crank. You may also get acceptable performance with an older 7/8s road triple FD such as FD-3303. Older ones have a min difference spec of 10.

Other than that, no issues. Note also that you can use an 8-speed STI if you want, such as Claris.


The difference in rolling resistance is small but can be seen in time trial results and maybe in mass start races. The more noticeable difference is that typically race tires have smoother ride because the thinner casing transmits less vibration.

Note that the categories are not clear and one manufacturer's tire marketed as training tire may have less rolling resistance than other's fastest race tire. One web site to check is http://www.bicyclerollingresistance.com/.

Is there a necessity? If you are racing and it is necessary to do everything possible to improve your placement.


What's the difference between Shimano HG and SRAM XD free hubs?

SRAM's XD and XDR drivers (their term) don't have splines, unlike Shimano and Campagnolo freehub bodies. Instead, their cassettes screw onto the threaded section of the driver as shown in the image below.

They did this to

Address the shortcomings of Shimano's Hyperglide (HG) freehub, namely that the small splines got chewed up
Because they wanted to implement cassettes with 10t small cogs, so they needed a shorter freehub body anyway. The diameter of those cogs is smaller than the diameter of typical freehubs, so the XD(R) drivers are shorter than the HG freehubs.
Because Shimano was not going in that direction at the time of SRAM's implementation of this standard (2015 or so)
Finally, to be different

SRAM explains that XDR is just the road version of XD. XDR bodies are 1.85mm longer than XD. I believe that MTB cassettes can mount to an XDR body with an additional spacer; Shimano actually does a similar thing because on the MTB cassettes, the biggest cog is cantilevered over the freehub body.
In general, most hubs will come with the option for Hyperglide (HG) or XD(R) bodies, and possibly Microspline, regular Campagnolo, or Campagnolo N3W freehub bodies. Yes, there are a lot of standards, and yes, Campy has two of them as well (N3W allows the cassettes associated with their 1x13 gravel groupset to mount). In any case, you would be able to change out the freehub if you buy a new one, provided you actually want to change your groupset. (If so, note that 11s road cassettes are interchangeable, and 12s road cassettes should be also.)
Basically, you will want the freehub/driver type that matches the groupset you are getting or that you have. If you have Shimano road, you want HG, keeping in mind that their road groups are expected to transition to microspline starting this year. If you have Shimano MTB, you want microspline. If you have SRAM, you want XD or XDR. On the off chance that you switch to Campagnolo, you'd probably want to get the N3W body if one is available; there's an adapter that allows you to run regular 9, 10, 11, or 12s Campy cassettes on the N3W hub.


Finding compatible thinner street tires for Giant ATX

Any 26" tyre will be fine, as long as it

Fits between your chainstays/seatstays/brakes/fork when mounted without rubbing
isn't too small (or big) for your rim's internal width
has exactly the same ETRTO diameter

Most of the versions of that bike seem to have a 2.1" width tyre, so its likely you'll be able to fit a 1.5" to 2.1" wide 26 inch tyre without issue.   26 inch is also known by the ETRTO size 559 or 559-widthinmm so yours probably have 559-53 or 53-559 on the sidewall.

  Just to confuse things, there are <26"> tyres that have a different ETRTO code, or may be so old that they don't have such a code.  You're not likely to find these on your bike, but you might find them for sale.  The ETRTO codes could be "26 inch" are 559mm, 571mm, 584mm, 590mm or 597mm.   You need to match whats on your existing tyres.

If you want thinner than 1.5" (or ~38mm) then you'll want to measure the inner valley width of the rim and compare it to the chart at What is the maximum or minimum tire width I can fit on my bicycle?

Remember to buy 3 new tubes as well, two for the bike and one in your bag as the spare.

My commuter bike is 26" wheel as well, and finding fast road-oriented tyres is challenging - the range is very small for sporty offerings, so you will probably be looking at commuter-tyres which tend to be more puncture resistant.  Still much faster than using knobbly tyres on the road.


New derailleur - shifts up smoothly, or down - but not both

You mentioned replacing the RD and cassette but not the chain. Unless somehow the chain is nearly new already, you should replace it along with the new cassette. Unless it's very worn, it's not likely that's what's causing this though.

This is almost always a problem with either the hanger alignment or the cable.

Cleaning and lubricating the cable does not eliminate it as a potential factor. If the housings are too short, if they're contaminated with something you couldn't clean out, or if the cable has any kinks within them, they could be causing your issue. Having too short of a rear loop in particular is a common problem.

Hanger alignemt doesn't have to be obviously bent to still be out enough to cause problems, especially if you're not used to looking at it. For better or for worse, getting it aligned with a proper tool is pretty much required to eliminate it as a factor.


Are helmets with chin guards safer than those without?

I wish they had them 20 years ago when I was much younger and rode much more difficult terrain, with much less respect (aka fear) than I now have. (I ride mostly technical XC, not downhill).

As far a protection goes, if the choice is a traditional light weight helmet or one like this, you will be better off with this. It is not an alternate to a down hill helmet.

Negative internet commentary on these tends to come from Downhill riders who do not believe they offer any real protection. As far as down hill riding, they are correct. They also tend to be good enough not to fall off on easy ground, and know how to fall if they do, so see no benefit over a light weight helmet.

However, I have seen some pretty horrendous injuries (google "Bicycle face plant") from riders face planting on paved and easy gravel roads. Most times its inexperienced riders doing silly things, rarely an experienced rider getting taken out by someone/something. These helmets are ideal for a XC rider who wants to keep his teeth and pretty looks, but is not prepared to spend hours suffocating under a heavy downhill helmet.

Will it protect you from a face plant - For XC and road riding, face plants injure the face, its messy, painful and scars last a lifetime, as does the loss of teeth. Your face will be protected.

Risk of chin guard snapping - at that point it would have been your jaw.... if you expect to fall off that hard, get a down hill helmet. If it does snap off, it has certainly done its job.


Locking Skewer slipping from rear wheel dropout

In my experience this is a problem with all such products. I use Pitlocks on my bikes and while they have slightly more corrugated interiors, they still slip. I have once sent a bike to be serviced and the shop extracted the Pit-locked rear wheel without damaging the bike or Pitlock. They said it was easier than making me post them the key.

Since my bikes are steel, it was easy enough for me to put a few spots of weld on the rear dropouts to stop that happening again. In your case it looks like an aluminium frame and aluminium locking surface, so putting "teeth" on either isn't going to help - the metal is too soft. Having a bigger barrier similar to the "lawyer lips" on a front dropout makes the locking skewer work.

So I don't think the problem is with the lack of teeth on the skewer directly, it's with the whole concept.


Kids bike overlapping frame sizes, can you go up one size?

In an ideal world, you'd keep the sizing matching the growth of the tyke. However, they grow fast enough that most people can't afford the money or space to keep a acquire bikes of correct size at all times.

The usual compromise (in the US at least, especially in families which aren't made up of cyclists) is to buy a bike which is bigger than necessary for the kid, and let them ride it until its too small for them. This is easier to deal with for children cause they don't start out with all sorts of body pain and they don't ride long enough distances for form and stuff to matter. Young kids are also a case where riding a bso is okay, in my opinion; they're not with the bikes long enough for quality to matter in most cases, and its not like they're going to learn upkeep until they're early teenagers anyway.

It'd be fine for her to ride the 16" bike, but there is the question of how long the 16" bike will be a good fit for her. It might be better to wait for her to hit around 120 cm and then skip the 16" bike or something (this is what I did).


Is it safe to ride while taking mucinex (guaifenesin)?

Plain old Mucinex (without the "-D" suffix) is guaifenesin, one of the most innocuous drugs in existence.  Unless you have a peculiar (and rare) reaction to it, it should be about as safe as one can hope for.  In fact, I'd recommend it if you ride in dry or dusty conditions.

Mucinex-D, on the other hand, contains a decongestant that can cause drowsiness and other such symptoms in a substantial minority of patients.  (And I believe it can also be picked up in pro sports drug tests.)  You should take that while riding only after you've established that you don't react to it (and you're not in pro competition).

Also, of course, if you find yourself getting congested on rides that's a likely sign that you need to drink more water.


Can I convert from a 52/42/30 crankset to 50/39/30?

When you do drive train swaps, you need to check the chain length, and the capacities and limits stated on the front and rear derailleur (look at their data sheets).

1) Check the data sheet for your front derailleur. It will specify the sizes of the chainrings and the teeth differences required. Almost surely it will be fine though. You'll have to fidget with the clamp position a bit.

2) You'll end up shortening the chain by a few links, ideally (you can run a too long chain safely, but why bother?). The cassette doesn't need to change.

3) No - so long as you stay with a <=9 speed Shimano RD and Shimano Road FD (I believe <=10 speed), you're OK. The RD doesn't need to change either.

Aside: 52/42/30 cranksets aren't uncommon.


How can I prevent glasses fogging when cycling in the cold with face covered

What you are looking for is a product that covers your face (to keep it warm) seals along the upper edge to your face (to keep breath from leaking up under your glasses) and uses a design to direct your exhalations away from your face (so your exhaled moist breath doesn't fog your lenses).

There are actually several products on the market designed to do these things.   Many people do cold weather outdoor activities (fat biking, skiing, snowboarding, snowshoeing, etc) have these issues and they are attempted solutions in various manners.  Chemical lens treatments, electric heat and or air movement, and design directed airflow are all out there.  I'd suggest checking with a local sports store and seeing what they support/use/recommend.


The rotor might not be perfectly true. Although the shop should fix it as it's a new bike, do be aware that big MTB rotors get out of true really easily and at some point you just need to live with it. This can be somewhat mitigated with two-piece rotors utilizing a beefier spider, but in the end you're riding trails; stuff breaks all the time.

Is your thru axle tight? I know that with 9mm QR forks, violently turning and braking can sometimes be enough torque to momentarily twist the hub/dropout interface out of alignment, resulting in noise. A similar effect might manifest if your TA is not done up properly.


Shimano Alfine lever does not seem to pump oil into the hose even with reservoir full

It turns out I just needed more patience. To fill the brake line, you need to:

Make sure reservoir is full of oil.
Open the bleeder port
Squeeze the lever in
Close the bleeder port
Release the lever
Wait about 10 mins for the oil to s.l.o.w.l.y. get sucked down into the line.
Repeat until oil is coming out of the port.

There must be a very small bypass port inside the lever assembly to let the pressure equalize over minutes.


Gears switch automatically on smart trainer

First, this is not a between-brands compatibility issue. Microshift products are generally compatible with Shimano. In fact, in 11 speed and below groupsets, Shimano, SRAM, Microshift and others all use the same standards for cassette sprocket spacing and chain width, and there is a general cross-compatibility.
Freehub bodies for 11 speed road groupset cassettes are slightly longer than those for 10 speed or less. 8, 9 or 10 speed cassettes need to be installed with a spacer behind them. Check that you used a spacer when you installed the 9 speed cassette on the trainer.
Also, on different manufacturer and model hubs (both on wheels and trainers), there is some variation of the exact lateral position of the free-hub body that holds the cassette. That means that if you swap wheels or put a bike on a trainer the adjustment of the rear derailleur will usually need to be changed.
Run through a rear derailleur adjustment process with the bike in the trainer to properly set the upper and lower limits, and the sprocket indexing. Park Tool Repair Help has very good step-by step instructions..


How important is a correct frame size for a Mountainbike?

I have ridden MTB for years, an fit between most manufacturers 17" and 19".

I enjoy tight technical Single track, and get bored quickly with long stretches of trail when time from A to B is solely a measure of physical fitness (hence I am not a road rider). I also tend to stick to short 1-2 hour rides.

I ride 17" bikes. On the fun stuff, I am more agile and able to really throw the bike around and respond to conditions, at the expense of a bit of power and a slightly cramped cockpit.  On the larger bikes I am more efficient and more comfortable when pacing out on straight roads for long periods of time.

Think of the difference between sizes like a sports car vs a limo. For a blast around a windy road, take a sports car, for an eight hour drive down the interstate, take the limo. Choose the size that suits the riding you will do most often.

One question I would ask about the shop and salesman - are they MTBers or road riders. In my experience, roadies a more likely to 'round up', and put you on the bigger bike and MTB'er will 'round down' and put you on the smaller.

Take the smaller bike for a test ride on the road and see if the cockpit feels cramped. Take the larger bike for a ride and see if you are stretching to make tight turns. Imagine being in a tight turn and being thrown off balance, could you move your weight to correct it. Can you hang you buttocks off the back of the seat and still have bent arms - as needed when going down steep hills.

I hesitate to make a recommendation counter to that of an expert you have visited. Find another bike shop, preferably one that specialises in MTB's and seek a second opinion.

As far as adjustments, modern MTB 'theory' is shorter stems and wider handle bars for stability rather than long stems.


Windsor - The Hour - Bottom Bracket Dimensions

In http://www.bikesdirect.com/products/windsor/thehour.htm it says:

Sealed Cartridge 103mm

Trying to find shell widths for 103mm sealed cartridges only gives 68mm as the only possible combo for 103mm the length. e.g http://sheldonbrown.com/harris/bottombrackets.html

So it should be 68m x 103mm.


Concerns with different brake types for the front and the rear wheel

Quick answer: Don't worry.

Front and rear are already "functionally different" on two-wheeled vehicles, to the point that we have different tread patterns and even wheel sizes (at least in motorcycles this is common-practice).

So, having brakes with different "feels" is not a problem by itself, unless this bothers you, or makes you over/underestimate breaking power due to a possibly stark difference.

Hope this helps!