How can I get started riding without spending a fortune (too much)? I've just recently moved to a city (Seattle) where owning a car seems less appropriate than it has to me in the past.  Before, I lived in a far more suburban environment where biking was more-or-less just meant for trails and your "typical" bicycle was a $150-$200 one at the nearest Walmart or Target.  I'm apprehensive about dropping $500 (or more) on a bicycle currently, and I am really just looking for the best way to get started.

Do I really just need to drop $500+ on a new bicycle and deal with the elevated costs?  And if so, how do I even know where to begin on what type of bicycle to pick out, since it would more than likely be my primary mode of transportation?

Yeah, buy a used bike somewhere, either at a shop that has a bunch, or off or Craig's List or another "want ad" source.  And, of course, there are yard sales.  If you shop carefully you can probably pick up a serviceable bike for $50-100.

But first study bikes a little to learn to recognize quality.  Look at the cheap bikes at Walmart and some moderately priced ones at a reputable bike shop.  In particular note the differences you'll see around the rear axle and around the crank.  The cheapest bikes will have a 1-piece solid crank, whereas good bikes have a 3-piece crank.  On cheaper bikes the "dropouts" that the rear axle fits into are made of stamped sheet metal, whereas on better quality bikes the dropouts are die-cast or forged.  Also observe the joining of the tubing of the frame -- better quality bikes will have smoother welds, etc.

Also learn how to check out the condition of a used bike.  A little rust is not a problem, but if you pick up one end of the bike and spin the wheel it should spin freely, and the wheel should not wobble noticeably as it spins.  A brief test ride should find the brakes working well and the shifters at least working (they will likely need a "tune up").  Standing over the bike squeeze the front brake and the move the bike forwards and backwards -- the head bearing should not have any noticeable play.  Grab the crank and shake -- again there should be no noticeable play.


Cracked rim around the spoke I purchased a pair of Carrera Vendetta wheels, 27.5" with 2.8" tyres.
I found a couple cracks where the spoke sits around the back rim.
Is it okay to ride or is it okay to weld them?

Cracks in the wheel rim do generally need attention. If the cracks are around the nipple and you're a gambling man you can keep an eye on the crack's propagation and maybe use it a little, if they're in the side/wall, it's possible failure will be a little more exciting.
If you purchased them recently you may wish to return or exchange them.
Welding is probably not an option (assuming they're aluminium).


Swapping Rockshox TwistLoc lockout to trigger lockout I have a Trek Top Fuel 8 with a Rockshox TwistLoc lockout system. Can I switch it for a trigger lockout?

Yes, I believe the Top Fuel has a Rockshox Recon shock - Rockshox have a "Remote upgrade Kit" for the job (Make sure the kit matches your shock) . Not particularly hard to do yourself, but you may prefer to get the LBS to to do it if you are no familiar with shock servicing procedures.


Diagnosing faulty circuit in vintage incandescent headlamp I've got a steel-framed bike with incandescent lights, probably from the '70s. Unfortunately, despite all my efforts to get it working, the headlamp refuses to work.

History

About six months ago, the thing worked for a bit, even with its ancient, yellowed wires and bottle dynamo from a different era, but then suddenly stopped.
About a month ago, I replaced the ancient incandescent bulb with a new one and cleaned the whole thing inside and cleaned the ancient bottle dynamo but that didn't make a difference.
This weekend, I replaced the wiring for both the front and back with new double wiring†.

With the new wiring, the bottle dynamo is easily powering the old taillamp, so it seems that it's neither the old dynamo nor the new wiring which is the culprit.

In the photo you can see the way the thing works. When I screw on the top, I bend the metal connector plate forward a bit in order to be more sure that it actually does connect to the bulb.

What might be going on here? — I doubt it could be any kind of short due to the fact that the cabling is brand-new and that the dynamo lights up the taillamp just fine (it even lights up with only a slight turn of the pedals, so it seems to be generating a good amount of current).

Tools

The only electrics-specific tools I've got is one of those screwdrivers which has an LED which lights up if the head detects a current. However, I'm not exactly enthusiastic to buy even more stuff for this endeavour because I've already wasted such a large amount of time and money...

† The old wiring was a single, ungrounded wire and I actually don't know what to do with the new ground wire because there's no obvious attachment point for it, so the new wiring is still basically a single cable.

I agree with another post that it is most likely an open circuit to the headlamp.  If there was a short your tail light would not likely be working, either.  Your screwdriver electrical tester is probably for standard wall power and may not detect voltage at this level.  If you could borrow a volt/ohm meter from someone you could sort this out very easily.

Almost every lighting system of that vintage used the frame as a ground, so all you need is a single wire each from the terminal on the dynamo to the headlamp and tail light.  It may be possible that you have the wrong half of your double wire connected to the headlight.  You can twist the ends of both wires together at each end to avoid this possible confusion.  You are correct that the dynamo and the tail light must be correctly wired or the light would not work, so the problem is in the forward part of the circuit.
One other thing to check is the attachment of the head light.  Make sure that you have a solid metal-to-metal connection of the headlight to the frame.  If you put in a non-metal washer or bushing, for whatever reason, it may be insulating the ground side from the frame.  If you want to test the head light, disconnect your tail light and hook the head light to that wire.  You will have to rig a way to ground the head light to the frame, but if you don't want to mount it where the tail light was, all you really have to do is hold the head light housing to a bare piece of metal.  You may not have enough hands for all of this, but if the head light works in that location you know that there is a problem with either the forward wiring or that the headlight and/or its mount are insulated from the frame.  If the head light does not work there, you know then that the problem is with the head light itself.


Patching waterproof panniers I've managed to tear a couple holes in my panniers. Nothing enormous; they can still hold their contents, but they definitely need patching.

What would be a good way to patch them, keeping them waterproof and hopefully durable?

They're Detours, 50% nylon and 50% polyester, just simple one-piece bags. They're several years old, and they were a gift - haven't managed to find the exact same thing online.

The reality is that panniers are very similar to camping equipment. You have, "50% nylon and 50% polyester". So go to a camping store or online retailer and find a patch kit designed for that fabric combination. It may be included with the kit, but if not, you'll need a sealing compound to cover the patch.


Zipp Showstopper Brake Surface Has anyone else noted a drastic reduction in braking performance with Zipp's NSW Showstopper braking system as they age?  Right now the dry stopping isn't great, but wet stopping is practically nonexistent.  The brake pads are the recommended ones and they are adjusted correctly.  The brake track looks and feels polished.  Zipp/SRAM examined the wheels and said everything is fine. This is the first time that they have heard of this problem?  Really? It used to be that I had to clean off copious amounts of brake dust after each ride - not any more.
The warranty will be up shortly.  Does anyone know of an alternate Shimano style pad that can be used without compromising the wheel?

The showstopper braketrack is a textured finish, with very shallow grooves carved into the surface to make it rough and abrasive. This abrasion is what was grinding the powder off your brake pads originally. Unfortunately the rubber of the brake pads has also been very slowly wearing down the surface of the brake track as you've used the wheels and polishing them to a smoother finish.

To test if this is causing the issue, you would need a second new set of wheels with the same braking surface. You will be able to feel the difference by simply dragging your nail along the brake tracks to see if one is rougher than the other.

As for improving the quality of your braking with the current wheels, you simply need to look at which brake pads perform best on carbon wheels with a traditional smooth brake track. Personally, I always found that the Swissstop Black Prince brake pads worked best for me. In the past few years, I've used carbon wheels by Syncros, Roval, Fulcrum, Campagnolo and Shimano Dura Ace, all of which had a smooth carbon finish. Regardless of manufacturer, I always found that the Swissstop pads worked better in any conditions than the pads supplied by the manufacturer (except the Rovals were supplied with Swissstop pads).


Disc brake freezing at end of ride At the end of my last ride the back brake started rubbing hard on the disc. It almost feels like the brake cable had popped out of the lever. The bike is relatively new to me, and I am not very familiar with disc brakes. I can take it to the shop, but I wanted to be able to fix myself in case it happens again. Any ideas on how to fix, or what caused this? It is a Specialized Epic with Avid brakes.

Ensure the axle is properly placed in the dropout and the quick release is firmly closed. If it's even a little loose, the axle can shift a bit and cause the rotor to be misaligned with the caliper.


Tire and Tube size mismatch I have a tire with 24x2.125 written on it, and the new inner tube which I'm planning to install 24x2.175-3.0 Is this too big for the tire and can be prone to punctures etc. or should be OK? It is a conventional bicycle.

UPDATE - I ended up buying a tube the same size as the tire and it fits perfectly. I failed to install 24x2.175 tube because a piece of it was sticking out, I worried that the tube would fold inside the tire and would wear off quickly.

If its unopened you might be able to take it back to the shop and swap for the right size, but the difference between 2.125" and 2.175" is 0.05" which is only 2.3 % smaller so it would probably work fine.

There may be a bit more tube than you strictly need, and this could make pinching the tube easier when fitting it, so do take care.

Otherwise, a tube is probably one of the cheapest parts on a bike, and buying another won't break your wallet.


Rental bike for holiday: wise to change handlebar style? For my next cycling vacation I am evaluating the possibility to locally renting a bike instead of taking mine along: the costs are equivalents and I would save the hassle of carrying the box around.

The rental services I am exploring offer either city/touring bikes with flat bars or cyclocross/road bikes with drop down bars, while I normally ride on flat bar.

Is it advisable to keep the same bar style on the rental bike, or "muscle memory" and other stuff will not be a problem? I'd gladly avoid settling problems while riding 100+ km/day.

Additional info: I am looking to cycling in Japan, Biwa lake and Koyasan. Therefore paved roads but hilly, not really away from civilization, but still with some roads among the mountains.

I'd recommend getting used to a new handlebar style (or frame geometry or any other change) slowly. On a multi-day trip problems tend to accumulate, so I would't recommend trying anything new. An additional problem with drop bars is that the brake and shift levers work differently and some people seem to have problems getting used to them.

You could try to rent a bike with drop bars at home and see how it works out.

Edit: For the kind of trip you are planning, many cyclists prefer drop bars. I would recommend trying out them if possible.


Riding into a headwind faster than my top speed - how is it possible? Recently we've had some pretty strong winds here -- today the weather forecast said 20mph gusting to 30mph, but a few weeks ago the gusts were supposedly over 40mph.  The forecast direction was within a few degrees of into my face in both cases.  The day it was gusting to 40mph (from a baseline of 30mph), just walking into the wind took considerable effort more often than not.

Even allowing for the wind funneling along the road etc. we can perhaps  knock a bit off that wind speed, but even so, I was making headway into the wind.  I know what riding at 30mph on the flat feels like, and 40mph downhill (in still air).

By these speeds, rolling resistance should be irrelevant compared to air resistance, shouldn't it (especially as I'm on flat bars)?

How is it possible to make enough headway into a headwind equal to your maximum riding speed that you can still stay upright? Lets assume 5mph ground speed into a 30mph wind (and flat ground).

You can do it, because your bike is connected to the ground.

The work done when moving an object is proportional to distance and resistance force (which consists of air resistance and rolling resistance for bikes). The air resistance depends on air speed (ground speed + wind speed), but distance depends only on ground speed. Going slower reduces the energy spent, even when air speed remains high.

As an extreme example, consider just standing in place in wind. You are not doing any work at all, but your air speed is still high. When going against wind, you will soon find yourself doing more work. And when going downwind, you are doing negative work!

For objects not connected to ground things get different. A balloon in 40 MPH wind would drifting 40 Mph downwind in ground coordinates and would have to use the same power to stay in place in ground coordinates as it would use to move 40 Mph in still air.

A numerical example may help. We know the power equation for bicycles. For a bicycle on flat ground, at steady speed so that there is no acceleration or deceleration, in calm wind conditions, for typical rolling and aerodynamic coefficients of drag for a flat bar bike (Crr ~ .005 and CdA ~ 0.4 m^2), and a total mass of 85 kg, the power required to go 30 mph (13.33 m/s) is:

.005 * 85 * 9.8 * 15.56 + 0.5 * 1.2 * 0.4 * 13.33 ^3 = 625 watts.

However, what would the required power be to travel at 5 mph (2.22 m/s) into a 30 mph headwind? In that case, airspeed will be 13.33+2.22 = 15.56 m/s but ground speed will be only 2.22 m/s.

.005 * 85 * 9.8 * 2.22 + 0.5 * 1.2 * 0.4 * (15.56^2) * 2.22 = 140 watts.


should I change my seatpost? I have a seatpost with spring suspension. Something like this one:
A friend of mine hit it with his leg while he was dismounting and broke it into two pieces. After putting it back, I noticed that the plastic piece that holds it together has a broken thread. The bike is about 1 month old, so it is still under warranty.

Should I leave it as it is and hope for the best, or should I go back to store and ask for a new one, alleging bad manufacture?

Also a plastic ring it is clearly to weak for that join should I just get a simple seatpost ?

If you prefer the cushion of the seat post, you could request a new one, especially if it keeps coming apart. It should be covered under the warranty. If you don't care about the spring support, a simple seat post will be more sturdy.


What does triple-hollow construction mean? I've got a set of Sun Rhynolyte rims and in the features it says they have a  triple-hollow construction. What does that mean?

When a rim is extruded, the shape of the material can give added strength to the rim.
There are many rim types, but the two most common are single-walled and double walled. A single walled rim uses a simple U shaped extrusion. A double-walled rim adds a cross brace across that U shape, creating a D-shaped extrusion.
Triple hollow construction add extra cross-bracing to that D shape, resulting in more than one hollow area in the extrusion. It is supposed to add strength to the rim. Compare for example the following image from Sheldon Brown:

Thus the name.


Can I replace my 1/4" wheel bearings with slightly smaller ones? On my back wheel on one side balls won't fit! I am 100% certain they are the same balls I took out easily with the magnet on my screwdriver several weeks ago to mail my bike home.  They are 1/4" balls.  I'm afraid if I get new balls, they wouldn't fit either since they are not worn any smaller.  I even tried freezing the balls to shrink them and get them in, but that didn't work.  Can I use 15/64" balls?  They don't seem to fit the curve of the cone snugly anyway, but they do seem to fit the cup.  I don't really want to take a ball out since it leaves such a large gap.

Are you sure you're putting in the right number of balls?  Generally, when a bearing is new there is about a half-ball space left when you have a full complement of balls.  As the bearing wears this gets to be closer to a full ball's space.  It's easy to see the space and think you should put in another ball, but you don't need one.

(To hold the balls in place, of course, dab some grease into the race.  Place the balls in the grease, and install the greased cone.  This makes it fairly easy to reassemble a hub.)


Left crankshaft arm broken - can I use a different manufacturer? Good evening,
My left crankshaft broke on my Voodoo Masala hybrid bike (Halfords). It has a Suntour XCT9 crankshaft.
Frustrating it’s cheaper to buy and entire replacement Crankshaft than the left arm alone. My question is can I use any 175 left arm or am I left working out what replacement crankshaft to put on it?
Thanks,
Paul

Generally yes, its not a problem, if the cosmetics are not a problem :)
You may find the Q Factor (how far apart the pedals are) changed and a pedals a little offset from center, but in reality this is unlikely to cause a big issue for most riders.


Cracks on tire - still safe to ride? I just experienced some uncommon cracks on the tires (Schwalbe Durano Plus)

The tires are pretty new (less than half year old, and used max. 1500 km).

I inflated 6 bars in the tire, and according to the specs 6-8 bars should be normal.
Is it possible that this cracks are caused by overinflation?
Should I immediately replace them or is it still safe to ride like this?

The type of tire cracking that is most worrisome is when it's accompanied by bulging areas from the tube pressure. This implies damage to the casing, which in turn implies a tire that might very realistically fail at any time. The casing is the major structural part of the tire, not the rubber.

Cracks in the rubber like this look bad but almost never result in any issues themselves. When they do, usually its actually something along the times of the casing getting damaged in some kind of incident or condition that also caused the rubber cracking.

There's some distant hypothetical risk that the crack makes the casing more vulnerable in that spot or causes some kind of stress riser, but basically it's fine.


Installing downtube shifters on a bike with no bosses or cable stops Following up on the same bike as my previous question, we were able to get it cleaned up an running very well at the end of last summer.

My brother has been riding it for a few months now and the main issue is that the SunTour friction shifter for the rear derailleur doesn't hold tension and frequently shifts to the smaller cogs on its own.

I bought a set of SunTour LePree downtube shifters to replace the shifter that's currently on the bike.

I plan on installing a clamp with shift bosses like:

However, there are no cable stops on the bike. The housing has been clamped like below and the shifter housing runs right up to the current shifter.

The new shifter doesn't have a cable housing stop and so I'm considering using a clamp-on cable stop on the downtube closer to the bottom bracket.

Am I on the right track or is there a better way?

For downtube shifters, I prefer to run as little housing as possible.  Your best bet is to look for some new old stock (NOS) vintage parts.  You need two bits: a chainstay-clamping housing stop for the short housing loop to the rear derailleur, and a downtube-clamping cable guide for making the cable bend at the bottom bracket up towards the front derailleur and back towards the rear derailleur along the chainstay.

A quick search of eBay shows both available pretty readily. Several manufacturers make the chainstay clamp, but the Campagnolo 636 is representative.  The best downtube clamp for both a front and rear derailleur looks to be the Campagnolo 626/A double guide, though Huret, Suntour and a few others also made them.


What are a 'coach lines' So contacted a bike restoration place for a quote to respray my BSA, the guy asked me do I want 'coach lines'. Too embarrassed to ask what they were I just said yes.

So what are they exactly?

Coach lines (stripes) are a type of thin stripes you saw on (typically British) cars. They were a hallmark on high end cars like Rolls Royces.

See this image from from this article:

The coach lines are the lines under the guy's hand.

See also the wikipedia article on Pinstripes.

My guess is that this bike may have had some sort of pin striping.


Can I replace a quick release skewer by something that needs a wrench to open? I have an old Motobecane with quick release skewers in both wheels (700mm wheels), that I only use for short commutes (so I don't use the quick release function if there is a flat; [also hadn't have a flat in years given the anti-puncture tires]).
I just had my front wheel stolen, while parked next to many other bikes with through axles without their front wheels secured, so now I'd like to make the front wheel exactly as hard (and as easy) and a through axle to remove (needing a wrench).
I don't want something that is harder to open (i.e., a pitlock) nor easier (Allen Key Skewer), I want something equal to the most commonly used old-school nutted axle.
Can a through bolt axle of the same width be used? (What do we search to buy such? My searching has at most given me at most Allen Key Skewers, which are still easier to open than with a wrench)
Thank you
EDIT:
So I should ask for a wheel intended for nuts of the same size (radius 700mm).
How do I know the size of the axle?

There is a list of products here
https://www.cyclingabout.com/list-ways-theft-proof-wheels-secure-components-locking-security-skewers-seatpost-locks/
Loosely:

A set of skewer ends designed to make your wheels unremovable unless you turn your bike upside down, which would be hard without removing the bike
Various proprietary tools that mean your wheels are unremovable without the right tool
Slightly more deluxe versions with the manufacturer making dozens of different tools/keys so that there is no chance a thief will carry them around

In general you won't be able to replace your skewers with bolt thru axles unless the unlikely event you have fancy hubs that are designed to take a bolt on axle.
E.g. https://www.hopetech.com/products/hubs/accessories/axle-conversion-kit/
I suggest something like this
https://www.evanscycles.com/brand/mpart/road-allen-key-security-skewers-930614
Is a reasonably cost effective solution


Can I convert rim brake to disc brake on road bike? I have a Giant propel advanced 2 (2017) road bike, 105 groupset, rim brakes. I would like to buy a set of deep section racing wheels and unsure if disc brakes are an option or not.

Is it possible to convert my bike to a disc brake version? If so, what component(s) would I need to change? How much would it cost? What are the differences between hydraulics and mechanical disc brakes? Or should I just get this crazy idea out of my head?

My bike:

Rim and disc brakes have completely different mounts. The front disc would be mounted at the bottom of the left fork leg, and the rear would be mounted where the seat and chain stay intersect.

It’s not just the mounting points: the tubes in disc brake bikes are different. the carbon layup is denser or the metal tubing is much thicker at the disc mount point and other places that are affected by the very considerable torque generated when you brake.

You might be able to replace your fork with the Propel disc fork, and mount just a front disc brake. This would not be economical. Also, it appears that the fork crown may be integrated with the frame, so I am not certain what third party options are available. You’d also need to change to a front hydraulic shifter/brake lever. You could just use mechanical disc, but compared to good rim brakes, the advantages aren’t huge. Search on the site for discussions of mechanical versus hydraulic disc.

You can get deep section carbon rims for rim brakes. These have some downsides - the braking is inherently inferior to aluminum rims, and you have to use special brake pads. Depending on the resin used in the rim, it’s possible to overheat carbon clinchers on long descents if you brake for extended periods. In that case, the problem isn’t trivial: you would damage a very expensive rim and you’d need to replace it. For reasons I can’t quite remember, tubular rims are less vulnerable to this issue, although they still have carbon brake surfaces, and tubulars need a different chain of logistics than clinchers.

Hybrid rims, like the Hed Jet, Bontrager Aeolus Comp, and some Flo Cycling rims, have a non-structural carbon fairing bonded to an aluminum rim. These are relatively heavy, but weight matters surprisingly little in cycling. (We are talking a wheel set weight of 1900-2000g for hybrid rims, versus 1500g or so for a full carbon clincher wheel.) Opinions may differ, but I would consider these if you’re set on carbon wheels.

Rim brakes are outdated in some sense. However, speaking from experience with both rim and hydraulic disc brakes, you’ll do fine on rim brakes! Good quality rim brakes have more than enough stopping power on alloy rims in almost all circumstances. That does need one minor caveat: your bike seems to have Giant-branded direct mount brakes that are positioned in non-standard locations for aerodynamics. I’m not certain how good those calipers are. It’s possible they under-perform substantially relative to normal rim brakes. However, the point stands that it is completely un-economical to convert your front brake to disc, and that there is no way at all to mount a rear disc caliper.


Busted my bike hub & derailleur (I think) - how bad is it? I screwed up :( Background leading to my foolishness: I've been straining my bike quite a bit with hills and inclimate weather, and I haven't been able to find my maintenance kit since I've moved, so in my busyness I've let myself push around on a squeaky rusting chain. I realize I may be learning an expensive lesson now.

Today I kicked off and start pedaling, finding my chain was jammed up and not moving smoothly through a full rotation. That has happened before with a poorly oiled chain and I've pushed or shifted my way back into relatively-smooth operation. Well I pushed and it was stuck, not moving forward at all. Should've got off there but instead I pedaled backward a little, shifted and pushed, and it moved a little. That inspired me to push harder, and in my haste I pushed recklessly hard to pedal forward. Well, it stayed stuck and felt pretty wonky at that point, so I calmed down my haste and got off to check what's wrong. I found the back wheel had tilt/camber to it and the derailleur was bent out of alignment - I was definitely not getting anywhere quick anymore!

I'll bring this to a local bikeshop ASAP to get repaired. Seeing what appears to be a weld severed, I'm not sure if this is a costly repair or a major overhaul I'm looking at. How bad are the damages, can you identify what specifically appears damaged and in need of repair? Is the frame and hub okay to keep and just needs a new derailleur?

From a different angle:

Rear wheel appears normal to me, no clear damage on axle, spokes, wheel frame or anything. I think the connection point for the rear wheel to the frame is what got busted in some way from my pushing, which led to the derailleur getting bent and the wheel off-camber.

Updated based on your edits and comments.

The severed piece of metal circled in the 3rd image is one of the cage plates, and was originally attached to the lower (idler) pulley bolt.  Beyond replacing the derailleur, there is no additional damage there.  It really does appear that you may only need to replace your derailleur (and chain).

Other items to check out, at least to verify that nothing else is broken:

If you can spin the wheel and it rotates cleanly on the axle and is straight and the spokes are unbroken, straight, and under even tension then the wheel is good. (If some of the spokes are deeply scored you may want to replace them anyway.)
If the freewheel spins cleanly, and there are no bent teeth or wobble then it is okay.  (Though if you're replacing the chain it may need replacing anyway depending on wear.)  Based on the way the derailleur bent it's not likely it damaged the freewheel, but it's still worth checking.
If the frame itself is not bent (the distance between the dropouts hasn't changed, they are still evenly vertical and level with one another, and the stays are all straight) then it's fine.  (If it's a steel bike then a small amount of bending is survivable, but if it's aluminium it's trash.)
Obviously the derailleur is trash, but the derailleur hanger might be too.  (It's hard to tell from looking at the back side like this.)  You'll probably want the shop to make sure it's not twisted, which would cause the derailleur to mis-align.
You need a new chain, no question, since it sounds like a jammed link is part of the sequence that caused this.


Why are chains sold in fixed lengths rather than by the meter? Why can't we purchase chain by the meter, in any length, instead of in fixed lengths? Then the chain could be cut to the exact length required, unlike current situation of throwing away several links. This might not be beneficial for end users, but what about large bike shops or even OEM bike manufacturers.

They do. Connex (Wipperman) sells bulk chain, as shown by this link, and these people also buy it by the spool. This is likely what bike manufacturers do, and I've seen it in a bike shop or two. I'm sure you can also get it at some place like McMaster-Carr or Grainger if you ask for ANSI #40 roller chain with the appropriate width (possibly by special order).

The only bikes which use bigger chains than a standard chains are custom, longtails, tandems or recumbents -- its just more convenient for 99.999% of the people to just get a standard length chain [and many of these are pretty close to just taking multiple chains joined together]. As for the few extra links "waste", they come in useful sometimes when you need to do a repair. And in net, its probably cheaper to just pick up a little plastic box which has a slightly larger chain than going to the LBS and asking the girl to break the chain to the exact number of links you need (remember, she needs to get paid and do the daunting task of counting/comparing the # of links in your old chain to the new chain provided you actually brought the old chain in. if you didn't do that, she has to assume you didn't muck up the # of links in the chain and you wont complain if your new chain ends up too short). And its quicker.


Urban rides map projects Some time ago I read about a project in which bike commuters tracked their paths in order to map then on-line and have a place to see the most frequent routes in their city. Do you know this or other similar projects?

Strava has a heatmap function you can enable on their route planner.  This will show the more frequently used streets and will vary intensity of color based on popularity.
http://www.strava.com/routes/
Garmin Connect also has a heat map functionality built in to their route planner.
http://connect.garmin.com/course/create
The garmin maps seem to be more effective in heavily used areas like city center and heavily trafficked trails, while strava seems to be a bit better at showing a bit more detail in both city and rural areas.
May also want to check out Race Shape's heat map, which seems to be a worldwide bike based heat map. Race shape pulls data from strava and ridewithgps.com to create these heat maps. http://raceshape.com/heatmap/
(Strava has taken over Raceshape and incorporated it in their premium product.)


Shimano Tiagra - Install smaller front chainring I recently bought a used Trek Checkpoint ALR4, with which I'm very satisfied.
The gearing is ok so far for going on plane ground an light uphills, but when going on long and steeper hills it gets really hard to push which I don't want to sustain on longer rides.

It has a 50 and a 34 tooth chainring in the front and I was looking for a way to replace the 34 tooth chainring with a smaller one. But as far as I can see, I would have to change the whole groupset with both chainrings ant the cranks.

My question is if there is a way to do this without replacing the whole crankset or at least keeping the front derailleur. I couldn't find any evidence online that this is possible without replacing everything.

EDIT:

Rear Cassette: 10x 11-34.

I've got spare a 11-42 rear cassette from my mtb, would this one possibly fit without chainging the derailleur?

Update with the solution I went for:

I changed the rear cassette from 11-34 to 11-36 (CS-HG 81-10) which worked straight out of the box without any adjustments.

For the crankset, I went for the Shimano GRX 2x10 46/30 crankset which was easy to install. I had to shorten the chain by 2 links. It took me quiet a while to adjust the front derailleur and at the point where it shifted correctly, there was some friction when shifting into the higher gears on the bigger front chainring (The chainline of the GRX is 3.4mm wider than the line of the Tiagra crankset). With no possibilities for adjustemnts left, I ended up bending the metal of the derailleur a bit. Im pretty sure every professional would have told me to buy a new derailleur, but now it shifts even better than before all those modifications and the disfigurement that I did to the derailleur is not noticeable if you don't know it.

I'm pretty happy with the gearing of my new setup.
Costs for the complete conversion approximately 120€ and 2 hours of my time.

Thanks for the help!

The Trek Checkpoint ALR4 has a Tiagra 4720 series groupset. The FC-4700 crank as a bolt-center-diameter of 110mm which will not support a small ring below 34 teeth, so yes you are looking at a whole new crank to get smaller rings.

The RD-4700 derailleur will not work directly with an 11-42 cassette, although 11-36 will probably work OK.

You should be able to keep the front derailleur - 48-32 or 46-30 sub-compact cranks have the same tooth count difference between the rings. You would just need to drop the derailleur on the seat tube a little. From the pictures on the page you linked to the derailleur appears to be a band-clamp type so there should no problem moving it (some braze-on style brackets prevent the derailleur from being dropped to accommodate smaller rings).


Adjusting air pressure in the Tyre /Tire I own a Trek 3500 and am an avid biker... I bike on roads mostly, but sometimes on trails too.. Is there any information anyone could share that would assist me in adjusting air pressure in the Tire? or is it through and through fully filled up tires?

I feel that there might be a necessary modulation to better the ride experience on flat and smooth (road) and difficult (trails) tracks...

I assume that:

you run stock Trek 3500 so you have 2 inch tyres
you are not 200lbs (judging by your photo, location and fever for fitness in your profile)

Start with 40 PSI on the rear and 35 PSI on the front and ride at that pressure for a couple of rides to understand how it feels. Then adjust +-3 PSI to see how the handling changes. If you ever get a pinch flat increase 1 PSI on front and 4 on the rear.

For trails, aim for a 10-20% height reduction on the tyre height on where it touches the ground when you are standing on the bike.


Does frame size inside a particular model affect the ride characteristics of the bike? I read an article stating
that the smallest of a particular model of bicycle doesn't fully reflect the original design concept of the model
when I was about to buy the smallest (430mm seat tube) of Pinarello FPUNO carbon.
Is it true ?

The idea here is that a frame is typically originally designed in a 56cm frame, or the equivalent median size for the "average size" rider.

When the frame design is tested and finalized, most manufacturers minimize the changes they make when creating the molds for additional sizes.

This can result in small sizes having a harsher ride than the median, and large sizes having a softer feel, and slightly less power transfer. This is accentuated by the fact that most riders on a small frame have less weight and mass with which to flex the frame, and larger riders have more.

Really high quality manufacturers, like Storck bikes, for instance, use progressively shaped and manufactured tubing, which allows for the ride on the smallest frames and the largest frames to have the same ride characteristics of the median original design.

I am not personally familiar with the manufacturing techniques of Pinarello bikes, but their unique frame and tubing shapes would indicate to me that they would need to design each size independently, which would give a consistent ride characteristic, regardless of size.

Pinarello is known for the stability of their ride, but also for having a heavier than average frame weight. A 56cm frame is typically around 1800 grams, while the Scott Foil or the Storck Fascenario 0.7 G2 are 1050 grams and 1200 grams respectively.

It is more important that the ride characteristics match what you want from the bike, than how much it weighs, of course.

Have you ridden and been fitted on the bike you plan to buy? If not, do so first.
(Full disclosure: I manage a shop which sells Storck. This is not an ad, but it is why I'm familiar with the topic.)


badass-stuck seatpost I've recently found a nice bike with a steel frame. Well I noticed the aluminium seatpost was stuck but had no idea how heavily. To be honest I never had a similar problem and underestimated that beast...

So here's my question.
I'm pretty sure the problem comes from the galvanic corrosion between the two materials, I understand that the post gets thicker due to this and therefore is stuck. Now I made some measurements of the seatpost diameter which gave me 27 mm which is correct.
Then I moved on to the frame, measuring the diameter just at the top and on a few positions further down. The result is, there's quite some variation: 29.7mm at top, 28.7mm further down. I've attached some photos: https://photos.app.goo.gl/Yt3s3ycS74GfBagA6

to me this sounds quite heavy and I would like to have your opinion what to try next:
a) try some chemicals
b) cut out the seatpost
c) sell the bike again (I wouldn't like to because I really like the frame, it's a Fuji Feather)

concerning a) I already tried WD40 without luck. I've got the hint to try ammonia:
Remove bottom bracket, having the bike hanging upside down fill the tube with ammonia and leave it for at least 2 weeks. Then there's hope to get it out.

concerning b) what tools would you suggest for such an act? How can I prevent to ruin the frame?

thanks in advance!

Use a really long tube as leverage on the end of a pipe wrench for example (used to grip and twist the seat post (around it's axis). combined with wd40, should get it out, if not the seat post will snap off most likely, if so you can either saw it into pieces using an iron saw blade and take the pieces out individually or as a last resort use chemicals to dissolve the aluminum.

If it's not too stuck you can use the seat for leverage but if it's quite bad you'll destroy the seat (pull out the seat rails) this way. Next step could be to install two big screwdrivers/Allen keys or something similar in place of the seat rails (after having taken off the seat) and tighten it back up again. Then you can use the screw drivers/Allen keys etc. for leverage without damaging the seat post.

Hitting the top of the seat post with a heavy hammer (in axial direction of the seat tube) whilst putting twisting force on the seat post can also help 'loosen' it.

On some seat posts (for example some older SR seat posts) you can use an adjustable wrench to grip the seat post after removing the hardware for mounting the seat. I've tried to illustrate how to place the wrench on the seat post in the image below (forgive the terrible drawing):

Using this method you can potentially get great leverage on the seat post without damaging it so far you'll have to throw it away (the same method can be used with a bench vice (as suggested by @Criggie ) if you have one (grip seat post on the same 2 planes with the bench vice)).

There is a guy on YouTube (RJ TheBikeGuy) who has some good videos on it... example:

Here is a video of the 'sawing out the seat post' method:


Trek 7100 multitrack I am looking to buy a used hybrid.  Its a Trek 7100 multitrack. How can I find out what years trek made this bike?  And how can I find the current value? Bicycle Blue Book doesn't list the Trek 7100 multitrack and the vintage trek site doesn't either.

Bikepedia list the Trek 7100 as having been in production from 2002-2012. In some cases you can determine the year of production by seeing which color combinations or components were available for a particular year. Bicycle values are difficult to state as they change over time and can vary greatly by geographic area. The msrp was highest at the mid $400 range. Your best bet is to look at similar bikes with similar component levels and compare price and condition.

.


Single speed crank compatibility I am attempting to build a single speed bike for commuting from various spare parts.  I'm unsure of what kind of crankset would be compatible with my frame.  I have read from a couple sources that I can use a typical road double crankset with one chain ring removed, but I'm still a bit unclear on how to precisely determine compatibility with my frame.

My question is, in the most basic terms, what factors need to be considered when choosing a crankset?

The frame in question is a single speed cyclocross, a Bianchi San Jose.

The most important thing to consider is your frame, not your crankset. You can make almost any crankset work for a singlespeed.

Your frame needs to have horizontal dropouts so that you can tension the chain. Or you can use a chain tensioner, which is essentially the spring part of a rear derailleur. Looks like the San Jose has horizontal drops, so you're fine.

As for the crank, all you really need to worry about is maintaining chainline, which means that your rear and front cogs are lined up. You can affect this on the front by moving your one chainring into the large/small position on the crank, or using washers to move your chainring slightly over. EDIT: Now the overall position of the crank will be affected by the length of the bottom bracket spindle, as this will also affect the chainline. In practice, I wouldn't worry about this too much, again, because you can slightly adjust the position of the chainring after the fact.

In the rear, you can shift your hub axle slightly if you really need to, but you should focus on getting the front right before you resort to this. Note that this only applies to freewheel style hubs. If you are going to run cassette hubs for a single speed, then you can sometimes run spacers to get the rear cog exactly where you want it. There are some less other common configurations that I won't deal with here as well.

The other thing to keep in mind is that chains are meant to bend somewhat, as seen in normal use on a geared bike, and so a small offset angle is not going to hurt you.


Why is it important to have good saddles? Why is it important to have good saddles? Other than the comfort in long rides.

Taken from the livestrong website:

A March 2005 article in "European Urology" discusses the overuse injuries that can stem from long-term bicycling. The article states that, although cycling can be a healthy, beneficial sport, some injuries can occur to the urogenital system. Genitalia numbness was found to be most common, reported in 50 to 91 percent of the cyclists, followed by erectile dysfunction reported in 13 to 24 percent.

Prevention/Solution

Although studies do not link bicycling with specific prostate diseases, the pressure of traditional seats can create problems for both men and women. Fortunately, there are several types of seats that can help alleviate that pressure and prevent injury. Look for seats with a split saddle, or one with a space in the area that would normally press into the perineum. There are more extreme options like the "no-nose" bicycle seat, the moon seat and the easy seat that are geometrically different from a standard saddle.


Giant anthem x4 26er for single track I can get a giant anthem x4 26er for a decent price but was wondering if it would be suited for single tracks, trails and steepish rocky dirt track descends? Also, is the anthem a good climber?

By looking at the current frame geometry at http://www.giant-bicycles.com/en-gb/bikes/model/anthem.x4/7865/45505/#geometry we can assume the following.

Descending:

HA: 71 degrees head angle is pretty steep for downhill but for flowy singetracks it will be good. For the "steepish rocky tracks" it really depends on what you consider steep. Anything more than 10% and at over 15km/h may feel uncomfortable on the 71 degrees HA.
cockpit: You can improve the descending characteristics of the bike by using a shorter stem and wider bars.
travel: The 4 inch front and rear travel will not be enough for the very rough stuff.
verdict: So if you are very interested in aggressive MTB trail riding then this bike will not be appropriate. If you are just starting out then it'll be OK.

Climbing:

HA & SA: The 71 HA and the 73 seat angle make for a great climber.
travel: The 4 inch front and rear travel make a great XC bike and will allow you to easily tackle long epic rides on the mountains (for example 30 to 80km rides). Increasing suspension usually reduces this number.
verdict: Really good climber especially if it'll come with good (light) wheels and appropriate tyres.


Avid Juicy 3 brake piston problems I have an 8-year-old old Avid Juicy 3 and I accidentally pressed the front brake lever while the wheel was removed. I used a flat-head screwdriver to reset the pistons. When I spin the wheel after resetting, it works fine, but when I press the lever it  doesn't retract and it rubs against the disk. I thought the oil pressure was the problem and I let some oil out of the system.

Is this because of the dirty pistons?
is it okay that I let some oil out? (Few drops of oil)

Plus the Avid Juicy 3's piston looks weird and I don't know how to clean it. It's shaped like a cone... (Plus plus, i don't know what kind of DOT fluid my brake uses –it's green.)

You absolutely should not have let fluid out of the system. If the brake was working before there was not too much fluid in the system. You will need to bleed the brake to remove air bubbles and restore the fluid level. (If the back brake has not been bled in eight years you should do that one too.) Dirty pistons and seals are usually to blame for non-retracting pistons. In extreme cases the whole caliper has to be disassembled and cleaned.

You can try to find the manual for Avid brakes by searching on the SRAM website. There is a 2006 manual which may apply.

Check out this Park Tool video for how to clean hydraulic brake calipers. It also explains how piston retraction and advancement works.


Did my 2015 rim have wear indicators on the brake surface? Should I expect an alloy rim from around 2015 to have had wear indicators, because it doesn't now?  I assume a decent manufacturer, and a rim that's neither the cheapest nor high-end and super-light.
I doubt I'll find an answer for mine specifically (Mavic A310 by the look of things), so I mean this is a
general sense. In my case this is on the back, and it's done about 12 000 km, sometimes fairly laden as that's the bike with the child seat.  I tend to use the back brake lightly, and despite mudguards it does get dirty. They appear to have been discontinued, and I can't find a decent resolution photograph to check myself.
I've just pulled a chunk of aluminium out of one of the brake pads, so inspected the rim carefully to make sure that wasn't the source. That's when my suspicions were raised.
While I don't really expect a definitive answer, it would be good to have a decent idea of when to build the new wheel.

As @abdnChap correctly stated, not all rims have wear indicators, which are usually one or more dimples on the rim or a groove machined around the whole rim. Without a wear indicator, gauging the amount of permissible wear is subjective (unless the rim is cracked, but you don't want to let things get to that point!). So, how are consumers to gauge wear using a ruler?
The image below, from November Bicycles, shows a alloy rim that they describe as being about worn to about half its life. As a side note, they mention that if that were a carbon rim, it would be fairly worn, and they also discuss that once a carbon rim's brake track has lost its initial woven appearance, it's time for a new rim.

The pictures below, from Bike Test Reviews and Bike Touring News respectively, show rims that are worn out.

How long should a rim last? It depends on the rider and the conditions. Dry weather is obviously conducive to long life. As November Bicycles discussed on their blog, some rim alloys are longer lasting, and some are less durable. Because the A310 was not a high-end rim, I wouldn't expect a top-end alloy, but that doesn't mean poor durability.

Supplemental information on Mavic rims
I found a technical document from Mavic. It doesn't say which rims have which type of indicator, but apparently they have used two different types. The traditional ones that I think everyone is thinking of (myself included) are dimples on the rim that wear away as you wear the rim out. When those are gone, you need a new rim.
Some rims had internal wear indicators that appear when the rim is worn out, rather than disappear. The document says that "the inside of the braking surface of the rim is machined on both of the wings of the rim." This post by Cycling UK clarifies that (to me) vague statement; the writer said the notches were on the tire retaining flange, which I assume is the bead hook. So, the indicators should appear on the circumference of the rim.
However, Mavic's wording seems to imply that some rims had traditional (external, in their nomenclature) wear indicators, some had internal, and some may not have had any wear indicators. I've not yet found a list of which rims had which.


Can I upgrade to SRAM GX Eagle from Shimano Acera 9 Speed? Thinking about upgrading my gear set to SRAM GX Eagle 12-Speed Groupset 175mm from a Shimano Acera 9 Speed 40/30/22 MTB chainset

Would this be compatible?

To clarify things, with a SRAM GX Eagle groupset that consits of a crankset, GXP bottom bracket, chain, gear shifter, cassette and rear derailleur the only part that might cause incompatibility issues is the cassette because the XG-1275 11-50 cassette requires an XD freehub driver body (XD body has extra space for 10 and 9 cogs, while Shimano-style body does not).

Still, you've got several options to choose from:

Get a more expensive XG-1295 or XG-1299 11-50 cassette (Shimano freehub body compatible).
Get a cheaper Sunrace CSMZ90 11-50 casstte  (Shimano freehub body compatible).
If your rear hub has compatible XD freehub body for sale, get it and a regular XG-1275 10-50 cassette.
If there's no XD freehub body available for your rear hub, you can buy an XD rear hub and relace the rear wheel. Or buy a complete, compatible wheel.


Shifting problems after removing and replacing rear wheel I had a mysterious flat tire on my rear wheel after I had left the bike standing for the workday. I removed the wheel and changed the inner tube. I didn't think anything went wrong while doing that (e.g. I don't think I bumped the derailleur) but I did notice that the brake disc was rubbing slightly on the inner pad, so I adjusted the pad a tiny bit and it seemed to be fine. The disc wasn't visibly wobbling when I looked at it between the brake pads.

On the ride home, the chain was sometimes skipping on the rear sprockets and I had frequent trouble shifting. I suspect that the derailleur is misadjusted. Both the chain and rear cassette are pretty new, and I had no skipping problems before I changed the inner tube.

Before I try adjusting the derailleur, is there something else I should check? Is it possible that the quick-release skewer is too tight or loose causing the wheel to be misaligned?

Per your comments, looks like you just needed to re-seat the rear wheel.  To be fair, I will say there are things you can do while changing a tire that may cause problems like this.  But having to adjust the disc brake, then the shifting acting wrong is a dead giveaway that the wheel went back in a bit of a different angle than it came out.


Fenders which fit above rim brakes? My bicycle is pictured below; you may notice that the front tire is wider than stock, and I'm intending on replacing the rear similarly whenever it needs to go.  The challenge is, I want fenders so I don't have to worry about getting caught in the rain, but there is not enough room between the fork and the front tire.  Do I need to find a creative sheet-metal fabricator, or is there an off-the-shelf option of some sort?

You could do this with off-the-shelf reacharound brackets. You can also make them out of leftover rack upper stays or other flat strip metal stock.
The idea with them is you take a fender set and cut them where the fork crown and seatstay bridge are, so the fenders don't have to go under them or the brakes. Then you drill holes in the cut off pieces and bolt the brackets on.


Are there rim brakes for road bikes compatible to Shimano hydraulic brake levers / brifters? Are there any rim brake calipers with road-style mounting compatible to Shimano hydraulic brake levers, specifically ST-U5060?

are Magura ST-06 / ST-08 compatible?people combine Magura disc callipers with shimano levers succesfully, dubbed "shigura", but I couldn't find a hint of anyone having combined ST-06/08 with any other lever. I guess they're too uncommon for this.

I'm looking for a way to have both shift- and brake levers on a triathlon bar's horns, like this question or this question. To my knowledge, there's only:

the ST-U5060 that's only for hydraulic disc brakes
a combination of brake levers clamping on the horn outside and SRAM shifters
-I couldn't find the brake levers.
drop bar brifters on the horns (which results in an awkward angle of the levers on my particular triathlon bar)

I would pick up a pair of cyclocross-style brakes levers that are designed to mount on the flat part of the bar and run inline with the brake cables. You can also mount them to the end of the bar and just have the cable terminate at the lever. The angle might not be quite right with the bullhorns, but some levers come with an adjustment screw that lets you set the default position of the lever. I would make sure to get some like that. And then you can just use whatever bar-end shifters you want.


Ksyrium Equipe wheels any good for Cyclocross? Just got a pair of Ksyrium Equipe with a second hand Sworks Tarmac. Thinking of putting them on my Ridley for some Cyclocross action. Has any one used these wheels for this purpose before? I have use Mavic wheels in the past and find they have a tendency to buckle or break spokes quite easily. Will I just be destroying a set of decent wheels?

Thanks

It's probably not a great idea, although they might not be a terrible option as pit wheels (where the choice is finishing in less-than-ideal conditions or DNFing).  The Equipes I've seen have fairly low spoke counts (20 or 24) and are narrow by contemporary road wheel standards (19mm).  There's no reason to go with such low spoke counts for CX even if you're pretty small, and as Zippy The Pinhead mentions, the spokes are nonstandard.  (IME, almost everything about midrange and lower-end Mavic wheels is unnecessarily difficult to service, though.)

Mavic claims you can mount a 32mm tire on these rims but the sidewalls will stick so far out from the edges of the rim that you'll have a crummy contact patch and will need to run awfully high pressures to avoid pinch flatting.

The good news is that you can probably sell these Equipes (if you have no other use for them and they're in good shape) for $300 and then get a set of decent CX wheels built up with Major Tom rims, midrange hubs, and all-around tires for around $500.


Stuck Bottom Bracket I have an 80's Fuji bike and It's definitely well past time to replace the bottom bracket. The adjusting cup came off fine, but the crank side cup is super stuck. I've tried stacking lockring washers and cranking the crap out of it. I've tried any kind of penetrating oil, almost broke my park tool for removing keyed rings. That sucker is stuck. It's been driven through a couple winters and I don't recall ever being able to remove that side.

Any ideas on how to get the crank side cup off? Is it just easier/cheaper to find the parts and rebuild it?

OH and yes I know it's reverse threaded! :D I'll be sure to grease the crud out of the new one when I can get it in.

A 1980s Fuji should have an English bottom bracket with a left-hand threaded fixed cup.

A few methods I have used to remove very stuck bottom brackets:

Use the Stein Fixed Cup Wrench Clamp (FCC-2) to secure the wrench onto the fixed cup.  This will allow you to apply more leverage without the tool slipping off.  It also allows you to pound on the tool with a mallet which sometimes helps.
Clamp the flats of the fixed cup in a vise and turn the frame.
You mentioned keyed rings - if the fixed cup does not have flats on it, you could flatten the sides with a grinder and then stick it in the vise.
If there's any chance that thread locking compound was used (probably not likely) then applying heat would help move it.


Can park tool bbt-59 take off ultegra sm-bbr60 I have a Ultegra SM-BBR60 bottom bracket on my bike and have an old tool that doesn't fit the bearing cups in order to get them off.

My LBS sold me the bbt-59 in order to get it off. However when using it attached to my torque wrench it wont lossen, and keeps slipping off eventually looking like it's starting to thread. So don't want to damage it anymore in case they won't take it back.

I have read here that it is the correct part. However I am not able to get it off.

Just want to make sure this is the correct tool to use, and if it does anyone know why it is not loosening?

The BBT-59 is definitely a correct choice in tool to use. However, you shouldn't ever break free tight things with a torque wrench. Ideally you would never use a torque wrench in the loosening direction. It's a bad practice. If you know the thing you're loosening is within the torque range of the wrench and its current setting you can kind of cheat there if you really want to, but loosening arbitrarily tight things like a BB cup is not a job for a torque wrench. Use a breaker bar.

The new Park external BB tools (BBT-59 and BBT-49) have inexplicably broken from the tradition of such tools having large external wrench flats for a big adjustable wrench, such as their and everyone elses' first generation socket-type external BB tools. Having external wrench flats allows you to play the trick of using a QR skewer or bolt plus some big washers to clamp the tool to the cup so it can't slip in case you're dealing with a tight or stuck cup. So instead you just have to position everything so you're using your body to keep the tool pushing hard inward as you turn it. If there's any thought process here at all, they probably did it this way because they made them out of aluminum so they can be non-marring, but didn't want people trying to turn the outside at high force with adjustable wrenches, so they eliminated the option. But if they cared about that they could have found a way to create a non marring contact surface and a steel body, same as using the freebie plastic adapter tool that Shimano includes with these BBs if bought aftermarket.

As for how to get it off, as in the comments make sure you're turning the right way (ISO BB shells have reverse threaded right cups). Usually the technique for a difficult one of these with that tool would be bike on the ground, knee or shin pressing the wrench inward against the bike to prevent slipping, tool started at around 45-60ish degree angle across front triangle, and try to find a way of putting all your body weight into it, or even use your foot. Having someone hold down the back wheel can help.


Chain overshoots cog when shifting from low to high gears Hi when shifting from low to high gears my chain is overshooting the cog and jumping into the next one. I tried turning the low limit screw outward to move the derailer in towards the low gears but it makes no difference so I think it must be the cable tension. With wear and tear I am guessing the cable has stretched so needs tightened at the barrel adjuster and not loosened? Thats my conslusion but maybe it is not that simple?! Any advice would be great, thanks. Dont want to mess with it too much before being sure incase it completely messes it up as I have done many times before :)

Decided to go with what I thought. Adjusted the rear barrell adjuster anti clockwise 4 clicks and the chain started overshooting in both directions (mainly at the low end). Undid the 4 clicks and the chain now overshoots in both directions at the low end yet hesistates to change when shifting from high to low (at the high end). Im summary gear adjustments are a dark art as I previously thought!

The following links will show you how to adjust a derailleur:

http://sheldonbrown.com/derailer-adjustment.html

http://www.parktool.com/blog/repair-help/rear-derailler-adjustments-derailleur

Note that cables and derailleurs do need replacing from time to time and they do need occasional adjustment, but try to follow one of the derailleur adjustment systems suggested in the prior links (assuming the derailleur isn't bent or something - if it is, take it to your LBS to be straightened). Limit screws only keep the chain going too far into the spokes or out of the cassette, and do not affect shifts between the largest and smallest cogs (only the extreme points of chain movement), so those should not have been tweaked (probably).

Note that bending a derailleur is quite easy even with a small spill. Your LBS probably can adjust this in 5 minutes if you can't figure it out.


Shimano Deore front derailleur occasionally sticking I have a question about my front derailleur sticking occasionally.  I've had this bike for a 1.7 years and have ridden it through 2 winters.

It has only been after this last winter that my front derailleur has been sticking on occasion where it's like grit has jammed in somewhere (which I'm sure it is the case).  When I'm on the fly I just knock it with my heel and it will downshift and I can push the shifter hard enough to go back up when I need to.

The first time I decided to overhaul both the front and back ones.  Took them apart, cleaned/degreased, regreased the two back cogs, and used WD-40 professional silicone on the rest of the parts as to not attract more dirt.

Then after about a month it got stuck again, and I couldn't see anything that could be jamming it (while it was still stiff as heck).  Didn't take it apart this time just used a tooth brush and silicone again and it's fine at the moment.

I'm assuming it may be that since that the roads have been grittier/dirtier from the winter with some recent rain and slush that it may just be normal.  I haven't been on the trails yet this year so I know it's not that.

Is this normal, has some kind of bur that I can't see come up and is catching grit?

EDIT:  I should also note that this is a hardtail mtb that I use for trails and winter commuting (a lot of salt and grit on the roads).

Put some chain lube (Triflow ftw) on the pivot points of the derailleur and go through its full range of motion a few times. You should start feeling a big difference. Also, you may find replacing your cables and housing to be beneficial - very easy to do on your own and relatively cheap to be done at any local bike shop.

Tip: WD-40 is not good for bike components. Use it to free up rusted screws- that's it.


700ccx28 rims with 25 tread and 28/32 tube does it work? So I have a pure fix, first problem, I replaced the rim strip and the tubes popped far less. I only replaced them a couple times from a nail and too much weight. I needed new tread, the shop owner put on the 25's and the tubes are 28/32 kendas. The tubes popped each time in the same place, near the stem. 3 different tubes. Is this a tube size issue or rim issue?

I think you need to find a new shop.

Your typical Velox rim strip should last on the order of decades unless a spoke goes through them or something (and that should be fixed, not just putting a new rim strip), so I'm not sure why it was replaced (or if it was done properly -- right size tape, covering all the spoke holes, aligned with the valve hole which is clean).

The tube size shouldn't be a problem. My suspicion is that you're not running high enough pressure, or aren't installing the tube properly (having the valve free and straight). I'm not sure why the shop owner didn't put a 25c tube in though, considering they're probably the most common size to have on hand.

As for tire wear, using brakes rather than skid stopping reduces tire wear. But, increased tire wear does come with the fixie territory, I suppose. Skidding wears the tire unequally depending on the chainring and cog size.


how to choose inner tubes I've always bought 700x28/38 Specialized inner tubes for my bike, because that was what I was told fitted. But what do those numbers mean? How do I know that a specific inner tube will fit my bike?

700 is the size of the wheel and tire which the tube is intended to fit. In this case, 700 means 700c, or ISO diameter 622mm rims. If you are unfamiliar with tire sizes, take a look here.

28/32 designates the min/max range of width of the tire which the tube is intended to fit, in mm. So in your case, your tubes are designed to fit tires of width 28mm (minimum) to 32mm (maximum). This range should correspond to the width of your rim as well.

Edit: From @Benson's comment on this answer (in case it gets deleted)

  Using a tube that's too big will mean it's exceedingly hard to get your tire back on, because the tube will have to fold out of the way. You'll risk pinching and damaging the tube as you put your tire back on. If you use a tube that's too small, you'll risk the tube stretching too far, which makes it much more vulnerable to popping.


How to prevent the derailleur cable fibres getting all over the places? My bike is only 7 months old, but the front derailleur cable fibres are becoming loose i.e. the individual thin metal fibres twised together to form the cable are loosing out. I think I have lost the metal cap which was holding the twisted end of the cable so that those fibres stay twisted. How can I fix this? Could anyone suggest?

TA

You can buy cable caps separately, they're actually meant to be crimped on so you can fix them with a crimper or pliers.

I know Park tools do something which is basically a really sharp wire cutter, should prevent fraying in the first place. This tool is showing on their site now but I have one (bought many years ago) which looks a bit different.

You shouldn't need to resort to duct tape!


Phil Wood Hubs: Anyone had a Pawl go? I got front & rear Phil Wood hubs for a touring setup back in Oct of 2011.  I'd been using them for commuting to work -- averaging 20 KM a day.  Except I'd been off the bike for the month of January, started again in Feb.

A week ago, things felt weird.  Discussed with a fellow cyclist at work, who said it sounded like the hub was going.  The following day, there was a loud crunch from the rear and the chain felt like it was slipping.  I took the wheel into the LBS who built the wheel for me.  They told me one of the four palls had an issue, and a spring was bent, so they corrected.  I picked up the wheel today, and got 10 KM before things started again - crunching noise from the rear, and a slip.  So I dropped the wheel with the LBS, who said they'll look for a rebuilt kit.

What is a pawl?  Is it part of the freehub?  Is a rebuilt kit enough, or should I be pressing for the LBS to RMA the hub?

Edit: In case anyone's interested, Phil Wood said they're aware of quality problems and wouldn't expect a rebuild kit to do much.  RMA time...

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

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


How do I determine what kind of replacement shifters I need? I need shifters for a 16 speed bicycle. When shifters are advertised as 2x8 is this referring to a bicycle with 2 sprockets in the front and 8 in the back?

You are correct that 2x8 refers to 8 speed cassette or freewheel and a crank with 2 speeds. The one that can be confusing is 18speed which can be an older 3x6 or a more modern 2x9. The other concerns is mountain or road drivetrain and Shimano, Sram or Campagnolo  compatible. You can search this site for compatibility questions that may match your specific circumstances.


Wheel keeps going out of alignment and loosening the chain I have an electric bike with internal hub gears on the rear wheel, so no derailleur. This means that for the chain to stay tight, the wheel axle needs to be dragged back into its seating before it is fastened so there is enough tension. However, ever since I removed my rear wheel once to change its tube, the wheel axle won't stay aligned. The side with the chain keeps slipping a few millimeters out until the wheel is at an angle and one side almost touches the brakes and frame, and also makes the chain loose so that it frequently pops off the sprocket.

It's driving me crazy, I've tried like five times now to readjust the wheel and fasten it, yet after riding for a kilometer it slides back. It happens no matter how much I tighten the nut.

I can see on the metal of the frame that the jagged washer of the nut has eaten into a bit and made marks, can this be the cause? What can I do about this?

The short answer is the axle nuts need to be done up tighter than you are doing them up it now. If you can't tighten them more, you need a longer wrench to be able to apply more torque.

There are tension adjustment devices that fit over the axles and in the dropouts that make tensioning the chain and aligning the wheel easier, and help prevent the wheel moving.

According to Park Tool, the nuts should be tightened to about 25Nm; see their video on single speed (or IHG) bikes for how to estimate that torque if you don't have a torque wrench.


New rear wheel compatibility with existing cassette I need to replace my rear wheel and have a few questions on component compatibility before I make a purchase.
My bike is a Specialized 2018 Rockhopper Pro; the link gives its stock components/spec.
I have modified it to run 1x11. (Probably) relevant specs:

Rear hub: Shimano Center Lock, disc, 135x9mm QR, 28h
1x11 setup with SunRace 11 speed cassette 11-46

Now, for new wheel choices I have considered the following two:

Shimano | Mavic - Deore XT FH-M8000 | XM 119 - 28 / 29 Inch Rear Wheel - Centerlock - QR
Shimano WH-MT500 29" 5/135 mm

Aside from the obvious - 29", QR, centerlock - what else do I need to be aware of in terms of compatibility? I'm unsure whether the two wheels will fit my bike. How can I tell if my cassette, for example, will fit onto the hub of the wheel?

One point not mentioned is the rim internal width.  This directly affects what widths of tyre can be mounted.  That is, a 60mm wide tyre will mount better on a wider rim than a 25mm tyre.
Additionally, tubeless rims are a thing.  If you want to run tubeless tyres, then a tubeless-ready rim makes sense.  If you're happy running clincher tyres with tubes, then this is less of an issue.
The hub's cassette interface has to match with the cassette you intend to run.  Options like Microspline are available.  As long as your cassette fits the hub, then the chain/derailleur won't know or care.
Spare parts - if the hub you get is some odd or rare item, then finding a new freehub in a couple of years could be hard.  Less of a problem than it used to be.
You want to consider your riding style as to the number of spokes - a rear wheel with more spokes is better at carrying a load or surviving a bad landing, while a wheel with fewer spokes is reputed to be lighter/more aero, but one spoke going can drop the whole wheel out of true enough to bind the wheel in the frame.


Upgrading an old road bike I own an old road bike from the 80’s I quite like. To this day, all the original parts are still on the bike, except the last mudguard that broke this year. The wear and tear is getting more noticeable lately, especially the wheels and the breaks. Shifting is not as smooth as it used to be, but it’s not a major concern. The wheels are probably the biggest problem since the wheel ring is not totally straight so the brake pads need to be further apart which is reducing the braking performance. Also last month 3 spokes broke. I am thinking of upgrading the bike for some time now, but I don’t know if new parts will fit on the old bike or if it can be achieved without spending too much money.

So I would like to replace the wheels because I don’t think it is worth repairing them. The current size is 27 x 1 1/4. I read a lot they can be replaced with 700c wheels. But when I look at 700c wheels I find a lot of different sizes mostly 29 inches. I don’t wanna buy wrong ones. My current last wheel has 5 gears. So should I look for a wheel with 5 gears as well ? A lot ot rear wheels online do not seem to have any gears.

The breaks are not the best anymore and it’s not easy even to adjust them. I am wondering what kind of brakes can I install on an old bike. Can I install something like Shimano sora brakes?  They are quite cheap for around 20€. I included some pictures of the bike and the brakes so you have a better picture of the bike.

Some pictures:

The bike

Front brakes

Front brakes 2

Rear brakes

Rear brakes 2

Regarding the brakes:
Your current brakes look like long-reach brake calipers to me (older type which has longer lever arms (less leverage). You have to account for the rim getting closer to the frame when you upgrade to larger wheels (I don't think you'll be able to find 27" wheels new, by far the most common size is 28" (700c aka 622mm inside rim diameter). If you are looking at road bike (or more specifically non-mtb wheels) the size 29" should not appear. 29" is often used for mountain bikes with big wheels (3 sizes in mtb wheels, 26", 27.5" (650B) and 29").

29ers or two-niners are mountain bikes and hybrid bikes that are built to use 700c or 622 mm ISO (inside rim diameter) wheels, commonly called 29" wheels.

"The name "29er" comes from a bicycle called the Two Niner, which was offered by the Fisher bike company in 2001, according to 1998 Mountain Bike Hall of Fame inductee Don Cook."

source: https://en.wikipedia.org/wiki/29er_(bicycle)
So 29-er mountain bikes do in fact use 700c or 622mm inside diameter rims. The name is just a bit confusing. Either way as long as you look for "road bike wheels" or "touring bike wheels" or "28 inch wheels" or "700c" or "622c" wheels you should be fine installing them on your bike (assuming there is enough frame clearance to fit the bigger rim/tire. The 28 inch wheels' rims do differ in width , i would suggest going with a similar width to your current rims (the width of the tire should be listed on the sidewall of your old tire and it should give you a good indication of your current rim's width, or you could measure the rim width with a caliper or other measuring tool to get a more exact figure. A wider rim will weight more, be a bit stronger, will allow for wider tires which will result in a cushier ride. If you go too wide the tire might not fit in the frame and it will start rubbing.
To summarize:
You need to account for the change in rim size for determining if you can install a certain brake caliper properly, from 27" to 28" this should be approx an inch in diameter so half an inch in radius.
If you would want to use your old brakes you could probably get away with it on the rear brake (it looks like the pads can be adjusted in upwards direction enough to account for the change in rim size), the front cannot be adjusted much more upward from its current position though..).
For installing the Sora (or any other modern short reach brake):
Check the minimum distance from the mounting bolt of the new brakes to the center of the pads and see if this distance matches the distance from the hole in your frame for mounting the brake to the center of the rim's braking surface.
I'm quite sure it should work (installing SORA) but please check (by measuring or preferably asking your local bike mechanic (which should have the parts so he can easily check compatibility) before buying new brakes.
For more info regarding this please check the part about "Reach" on Sheldon Brown's website: https://www.sheldonbrown.com/calipers.html
You should know older brakes like the ones you have usually use a bolt which protrudes all the way through the mounting hole with a nut on the other end to secure them to the frame, and modern brake calipers of this type use recessed nuts (they recess into the frame). If you want to use the newer style recessed bolts on your old frame you'll most likely have to drill out the holes to accommodate for the size of the recessed nut (the hole will be bigger than the current hole in the frame). On steel frames (which I think you have) this shouldn't be an issue though, just make sure not to drill it too large. For the front brake you could theoretically swap to a different front fork (which is more modern and does accommodate a modern recessed style mounting system (but if you have no other reason to upgrade the fork this might be silly).

Here is a video on how to install recessed style brakes on an old frame:

Regarding the wheels:
Wheels do not come with cassette/freewheel preinstalled in general. You'll have to make sure you get a wheel with the right system (either a freewheel hub if you want to reuse the old freewheel or install another (new) freewheel) or a free-hub body (for installing a cassette (which is the system used on (almost) all modern bikes)).
Free-hub bodies differ in length so you'll have to check if the one that comes with the wheel-set you buy is compatible with the cassette (amount of gears) you'd like to install. This info (compatible cassette speeds) should be listed with the specs/description of the wheel(set).
If you want to keep 5 speeds in the rear you will have to use a cassette (up to 7 gears you usually see freewheels and from 8 and upwards cassettes are used).
If you decide to upgrade to more gears in the back you will need a more narrow chain (which matches the amount of gears in the back (for example a 10 speed chain for 10 speed cassette). You will also have to replace your shifter (the one that operates the rear derailleur), assuming you don't have an index-less aka friction shifter (these can be used for all speeds as long as their range is sufficient (maximum cable movement that can be achieved with the shifter when moving it from max to min (or reverse direction) position).
Many people will say you'll also have to replace your rear derailleur but I've had much success using the same derailleur on many different gear setups. You do have to make sure the derailleur cage is long enough to handle the change in chain length when going from the smallest to biggest gear in the back (some mtb cassettes have a really big range meaning a small smallest gear and really big largest gear).
In summary: (regarding wheels)

You can replace the wheel with a wheel which accommodates either a cassette or freewheel, new wheels will almost always have cassette interface (aka free-hub body).

Usually cassettes start at 8 speed, going all the way up to 12 speed (but up to 11 is much cheaper, 12 is very rare).

When installing a new cassette or freewheel a new chain is recommended (since using old chain on new cassette/freewheel can/will cause faster wear or chain skipping teeth and such issues). Make sure the new chain matches the amount of gears on the cassette/freewheel.

Also upgrade rear derailleur if it can't handle the range (doesn't have enough capacity (measured in number of teeth difference) to accommodate the new freewheel/cassette (if it has a significantly broader range than the original freewheel).
Sometimes a derailleur's limit screws won't allow for enough adjustment to get the same derailleur properly adjusted on a different cassette/freewheel but you can oftentimes simply install longer adjustment bolts to fix this issue (remove old ones, find longer versions with same thread and install).

If you have or would like to use indexed shifters and you change to a different number of gears in the back you'll have to upgrade your shifter to an indexed variant with the correct number of gears (/clicks), you could alternatively install a non-indexed friction type shifter (which should in my experience work with any speed as long as the cable movement range is sufficient (as a fore mentioned))

if you would like to keep using a freewheel (you could for example buy a second hand wheel-set with a freewheel hub) you could upgrade to 7 gears in the back if you would like, this should be as simple as removing the (if installed) old freewheel and screwing on the new (7 speed for example) freewheel. You will need sufficient


Octalink v2 bottom bracket on italian shell I'm re-building an old Italian Bottecchia mountain bike which has Italian BB shell (70mm) and the previous bottom bracket was a square taper with 130mm spindle (measurement confirmed via calipers.)

I taken from an old Specialized (68mm shell) a Shimano fc-m341 crankset that I want to install in my new bike. That crankset was mounted with a shimano es-25 121 mm long.

My question is: which octalink v2 bottom bracket should I buy to fit my crankset on my project? I know I need an Italian threaded BB, but should I buy a 130mm, 121mm or 118mm spindle?

Due to the wider shell, I don't know if I have to buy a 130 mm as the previous square taper was, or a different size.

The spindle length depends on crank and chainline (distance from center of top tube to chainrings). In road bikes the chainline is almost always around 43 mm (exception being boost spacing), so the safest bet is to pick the same spindle length as on the bike where the cranks came from.

Different cranks may have different chainline on the same spindle.

If you can reassemble the original bikes, you should be able to measure the chainline on both of them so that you can see if you need to change the spindle length.


Why does a decimal sized 26" tire fit my rims but a fractional sized 26" tire doesn't? I'm replacing some 26 x 2.10" mountain bike tires that I have on my bike with some thinner 26 x 1 3/8" road bike tires for commuting, however somehow even though they both say that they are 26" the new road bike tires are too big for the rim!

I can take the new tires back, what should I look for when picking out a new set of tires?

You ask what to look for when buying MTB rims.

The most obvious thing would be ask for Mountain Bike tires (slick tires in your case) at the shop. Just using the words "mountain bike" is enough for any shop attendant.

Now if you want to take a tire and, just by looking, tell if it fits your rims, you must look for the ETRTO code, which states the inner diameter of the tire bead in milimeters, which is 559 for MTB.

So you have 47-559 (read right now from one of my tires) to be equivalent of 26x47 (47mm wide, or roughly 1.9)

Hope this helps


Does it support disk brakes? I found these holes (as in the pictures) and wanted to know if it supports disk brakes or not.
I am upgrading the whole thing and calculating a budget.

Thank you in advance :)

No. Those eyelets are for mounting mudguards or fenders.


Exceeding speed limit with Ebike, is battery affected? I bought a ebike and happy with it. My 30 mins ride to work every day dropped to 15 mins.

But according to law in country where I live motor stops when I exceed the speed limit which is 25km/h.

Since I am using ebike just for assistance I am pedaling as well. But most probably I am dropping below 25km/h(very often) and motor is being on again(or is it?).

I wanted to ask how this being on-off frequently(which can be my rich imagination) situation effects the life of the battery?

Actually, when you are running the motor near the top of the speed limiter, it's the happiest and most likely drawing the least current. If you had a CycleAnalyst or other amp gauge, you'd see it reduce current as it reaches the point where the controller is turning it off to reduce the speed. The motor will be cutting in and out due to the limiter, but will otherwise be just fine with this regimen as it's effectively operating on a reduced duty cycle at full speed - optimal conditions. This is quite unlike internal combustion engines which don't like to be operated at the highest end of their RPMs.

Furthermore, when you're running at full speed, air cooling to the controller, battery, and the motor is at its maximum, so they're at their happiest thermally.

The hardest thing on an electric motor, controller, and battery is starting up from a dead stop and going slowly up a hill. This is when the motor requires the most torque and thus draws the most amps - but also has the least airflow - which means everything heats  up and potentially reduces their life.

As I noted in my comments, though, the best way to extend the life of your (presumably) lithium batteries is to not drain them to 0% and to also not charge them to 100% -- but for the latter, you'll need a charger with an 80% or 90% cutoff. These are sold on the after-market. With careful dis/charging practice you can extend the number of charge cycles from 300 cycles to 900 or more.


Pain in the toes while cycling using clipless shoes I am not sure why I get a pain in my toes. After some 75 km of cycling, I don't find it right. The blood starts to clot in the tip of the toes.
After I lift my legs while lying down, it gets alright.
I am not new to cycling. I have done a lot of cycling but not much with my clipless shoes.
I feel that the shoes are sharp in front end to add to the aerodynamics.
Should I change my shoes? What should I check for while buying clipless shoes?

In addition to getting the right size shoes. Make sure the cleats are adjusted correctly. It sounds like you're getting something similar to "black toe" experienced by hikers and runners. It's usually caused by their toes getting jammed to the front of their shoes (imagine walking down a steep incline).

If your cleats are too far back people tend to point their toes down while pedaling. The cleats should be centered under the ball of your foot, depending on riding style/ experience, they can be moved forward or back by a few millimeters. in a perfect world every shop would have professional fitment analysis to take the guess work out of all this. This also happens if the saddle is too high, people don't realize this when making the switch to clipless pedals.

What I use to tell clients when buying new clipless shoes is to make sure they are snug around your arch and heel, but you're able to wiggle your toes comfortably.


Third eye helmet mounter mirror swivels too much I've got a "third eye" type bike mirror attached to my helmet.  It has two points of articulation: one near where it mounts to the helmet, which controls how far it swings up, and the other near the mirror which adjusts the mirror angle.  When I first got it, there was some resistance to adjusting it either way, so once it was adjusted it just stayed in place.  However, over time this resistance has decreased, to the point where the movement of air past me down a steep hill, or turning my head suddenly causes the mirror to move or the whole thing to swing out away from me.  In either case the result is I suddenly cannot see behind me until I have time to safely move my hand up to adjust it back into place. As it usually happens at a time when it is not safe for me to do this, my ability to use the third eye goes away at times when I might need it most.

I have tried using hot glue to fix both ends in place, and this works for a while, but over time it keeps working its way loose, especially the side closest to the helmet.  At the same time, hot glue is not particularly flexible, so if I don't get it adjusted just right I wind up on my bike having to turn my head one way or another to hit the sweet spot where I can see directly behind me.

What it seems like would be useful is if there was some kind of fluid that I could run over the contact points which would increase the amount of friction enough that either end would stay put when I'm not trying to adjust it, but not enough to prevent me from adjusting it whenever I need to.  Kind of like the opposite of oil, and ideally something nothing sticky to the point of attracting too much dust and grime or otherwise making a mess of my hands whenever I try to adjust the mirror, yet long lasting enough that I don't have to apply it more than maybe every month or to.

Does something like this exist?  Or is there some other solution that can be recommended?

Update: Here is a photo of the mirror attached to my helmet:

Chewing gum, or putty. You do not need to put the friction-increasing substance inside the joints - you can put it outside. Easier to remove later. You can also wrap sticky tape around the joints (if it's not supposed to move, but does, use duct tape; if it's supposed to move, but doesn't, use WD40 :) ).


How to keep square taper cranks tight? I have this recurring problem on many of my fixed-gear builds where the non-drive-side crank arm starts to wobble and gets loose after a very short amount of time (sometimes after just a short ride where I skid stop a lot).
These are usually new crank arms, sometimes steel ones, they're not bottoming out and I'm liberally applying lock-tite to the threads of the bolt. The BB in the latest case is new as well, though I'm hearing a little grind with each rotation).
I don't have a torque wrench and if I did I wouldn't know how much force to apply anyway since I don't have specs for my parts, but I'm just wondering - what am I doing wrong (or NOT doing)? I don't want to overtighten (I've had seized cranks before) but other than just reefing on them, I'm not sure if there's anything else I should be considering (other than replacing the technician!!)

You are undertightening the crank bolts on initial installation. 44Nm or 33 ft-lb work well as generic values for square taper cranks. A basic large beam-type torque wrench works well for crank bolts. If you aren't able to get one, it's safe for basic square taper cranks to reef like mad with something like a 12" ratchet or breaker bar. You'll be exceeding that torque value, but bad things won't happen. Fancier cranks with no extra material to give could eventually crack by doing so, but probably won't.
Always grease the threads and the bolt shoulder. Loctite is not optimal in this application, but it's also sufficient as an assembly lubricant to keep damage from occurring as long as there's appropriate torque.
Once the crank has come loose on the spindle, there's no fixing it. The press interface will never be right again. Throw them away. The spindle is hardened steel and is unaffected in almost all cases. If you're wrenching for others who have this problem, you must not re-install the crank. Doing so is irresponsible because the next time it comes loose, it might happen suddenly and cause a loss of balance and potentially a crash.
Square taper crank interfaces that are correctly installed don't have problems with seizure.
Some perceived loosening of the bolt is normal because as cranks are ridden, they can move around on the spindle enough to decrease thread preload. This is part of the reason why crank bolts are such high-torque fasteners; they must have some extra preload to give to avoid problems from this effect. Jobst Brandt wrote extensively about this on rec.bicycles.tech, material you can find archived by searching around. There are some dynamics happening that aren't readily apparent. Part of the conversation involves whether to grease the taper or not, which I won't get into here because it's outside the scope of the question, and in the end it's fine either way with some qualifiers.


How does hub diameter affect aerodynamics? There is a lot of discussion out there about spoke, rim & tyre drag, but almost nothing concerning the aerodynamics of the hubs.

What got me started on this is the fact that road hubs still have a relatively thin appearance, whereas Shimano's (and many of the rest) Mtb hubs follow their 'parallax' shape, which is much wider in diameter.

Naturally, the spokes and rim cut the air all around the hub so it can't be as important, but to what extent is the hub a factor with overall aerodynamics?

The key factor here is that the air at the hub is dirty - it's been disturbed by passing through the spokes and around the rim, so it's moving faster than the still air at the rim (slower relative to the bike), and it's turbulent. That makes improving aerodynamics both harder, and less important. The damage has already been done. Having a smooth outer surface is more important, since that's in cleaner air, and keeping it as small as possible since bladed spokes almost certainly have lower air resistance than the solid hub.

Mechanically a rim brake hub is a pair of flanges and a spacer. Since with bikes the goal is "everything as light as it can be", making that spacer smaller is a win. It needs to be big enough to enclose the axle, and strong enough to hold the flanges apart, but the job is not much more complex than that. So it can be very small and light.

With a disk brake the hub needs to be stronger since there's a torque between the disk rotor and the flanges. For the same reason it's rare to see a multi-part hub. That braking torque means a larger centre section allows thinner walls. Some mountain bikes also have thicker axles than road bikes, and obviously with those the minimum hub core diameter has to be larger to enclose the larger axle.

What definitely does improve the aerodynamics is making the hub much bigger, eliminating the spokes altogether. Which is why the UCI does not allow it :)


Advice on correct spoke replacement I need a replacement spoke for a Shimano WH-MT500 29er QR.
Shimano dealer manual does not mention the spoke length.
I've figued out its a 13G, double butted spoke but unsure about the length.  I've measured other spokes on the bike and from the hub to the base of the rim, including nipple, they are 290 mm. There are various sizes to buy online including 290 mm and 300 mm.  is there additional length beneath the rim I need to account for?
290 mm or 300 mm?

The easiest method would be to remove one of the spokes, measure the length , and reinsert the spoke. The length of the spoke needs to be such that all of the spoke's thread is inserted into the nipple's thread. Iirc most nipples have 19 revolutions of thread. Which should be approx 8-10mm length. Keep in mind the first part of the nipple is unthreaded (bore).

Depending in the rim's wall thickness and spoke nipple flange thickness (thickness of the wider part of the spoke nipple) you will have to add some extra length to the spokes if you measure them whilst in the wheel. This should be approx 3-4 mm for most wheels. But as previously mentioned the other method is more accurate (measuring removed spoke).

some more info on the bore: Purpose of 'bore' on spoke nipples - why are spoke nipples not threaded through their entire length?


Can I swap BMX wheels for a larger size? I am a 5 foot 10 inches 14 year old boy who would like to get into riding a BMX. So if I was to buy a BMX with a certain size wheels, can you swap them for bigger wheels

If you are 5 foot 10 then you will be fine on a full size 20" wheel BMX. Each model size will be built for the specific wheel size, things like tire clearance and brake positioning will normally mean you can't increase the wheel size.

You might like to research how top tube length and bar rise affect the handling of a BMX for jumps and tricks. There is a question on BMX sizing here BMX Bike Sizing and Changing Parts? and probably lots more on the site to read through