17

There are many possible causes of creaking. But Deemar has the most likely reason in this case - the cranks are loose on the axle. Think about how a creak is produced. It's one item sliding over another. But instead of sliding it's repeatedly sticking then jumping. The amount of movement might only be a fraction of a millimetre. The OP would have noticed if ...


15

The bottom bracket spindle is for cottered crank. The bottom bracket looks like threaded one, so it is likely that it can be replaced with square taper or external cup bottom bracket. To tell which thread the bottom bracket has, we'd need to know the exact dimensions.


15

The bottom bracket is not damaged, the left hand crank arm is. You have a 'two piece' crank where the right side crank is permanently attached to a steel axle, and the left hand crank clamps onto the axle with two pinch bolts. The axle has small splines cut into it where the crank clamps on and the crank has corresponding splines cut into it. for the crank ...


14

There are multiple components that can contribute to a clicking or grinding sound in your drive train in addition to the bottom bracket, including the chain, the pedals, the derailleur and the rear hub. That said, the symptoms you describe seem to indicate a problem with the pedal bearings or the bottom bracket. Here are my steps for troubleshooting the ...


13

I'm going to limit this answer to Shimano Hollowtech II BBs as per the question. Some other brands do it a little differently. Mountain external bearing crank spindles are longer than road spindles, and their respective bottom brackets are sized to fit one or the other. Shimano BBs have a plastic sleeve joining the two cups that protects the bearings from ...


11

First, very nice drawings and measurements. This makes answering easy. According to the Sheldon Brown link, for JIS "The standard width across the flats at the end of the axle is 12.65 mm", which is very close match to your measurement. ISO would be narrower at 12.33 mm. Many European manufacturers switched to JIS square taper before two piece cranksets ...


10

Like you said, they are cottered, what makes them aligned is that pin through a hole, which at the same time tightens the crank arm around the axle. If you google "cottered crank", you can see the spindle, which has a slot in each side. My hypothesis would be: or the cottering bold got deformed, or the spindle slot itself got deformed, or both. A bolder ...


10

You need one of four things: An eccentric bottom bracket. Like these An eccentric hub. Like these Horizontal dropouts. Like these A chain tensioner. There are a number of different types. You only need one of the four, but these are the only ways to get the chain tension correct on a single speed. (I should say "almost only." Blind luck works every so ...


10

It's hard to tell from your picture because they're out of focus, but they look a bit like grease nipples: i.e. like the ones in the top left of the picture. Do they have the little ball bearing in the middle?


10

By "non-drive" I assume you mean the left side. This is more apt to come loose than the right because of "precession" -- most crank bolts are right-hand thread on both sides, but the motion of the crank arm relative to the shaft tends to loosen the bolt on the left side, whereas it tends to tighten the bolt on the right side. But if this is occurring it's ...


10

The clicking, only under load and always at the same point of the stroke, can be due to: A bad pedal. I've had this a couple of times. The crank arm slipping on the crank. Generally if you've been riding it this way for more than 100 miles or so the crank arm (and possibly the crank) will have been permanently damaged, but tightening the fixing bolt may ...


10

FAG bottom brackets (BB) with plastic mounting rings are very common in Germany. The cartridge bottom bracket is really good and resilient, however the polyamide (PA) mounting rings are horrible. As you found out there is a tool to turn the splined outside (rosette shaped). It is inexpensive and easy to get in Germany (< 10EUR). However, unscrewing the ...


9

The width across the narrowest part of the flats (end of spindle): JIS = 12.65mm ISO = 12.33mm Use calipers.


9

SRAM GXP bottom brackets can be user serviced, but it is usually unnecessary. To service your BB bearings, first remove the crank arms. Then place your thumb in the BB spindle hole, and bend the joint enough that your knuckle makes firm contact around the entire ring surface of the spindle hole. Pull outward using fairly firm pressure, and if necessary, ...


9

To prevent galvanic corrosion. When grease is appied, there is a thin film of grease that prevent direct contact between two different metal. To prevent water and contaminants, especially salt in the winter season, that would otherwise accelerates corrosion as discussed in (1) This will not work with plastic or carbon fiber (+epoxy as matrix) materials as ...


9

The TruVative power spline BB is a decent, if inexpensive design, and is unlikely to have failed through a design fault. All bikes, regardless of price or quality level, require periodic maintenance. One of the most common issues on a relatively new bike is the crank arms "seating" on the BB spindle, and needing the fixing bolts to be re-torqued. This ...


9

If one side screws in without problems, and you've verified the thread orientation, then it's not a compatibility problem. ( http://sheldonbrown.com/bbsize.html - scroll down to "bottom bracket threading".) Trying to gently tighten it with a wrench should be fine. If you encounter abnormal resistance, then you should start thinking about taking it to a shop ...


9

The "bolt" that broke is not a part of the crank. Your bike has a so-called square-taper bottom bracket and one side of the axle broke off. This axle is a solid metal part that runs from one crank arm through the bottom bracket shell to the other crank arm. It cannot be serviced and should not break. The most likely reason is metal fatigue. You'll have to ...


9

4mm at the closest point is about the safe spot. 3mm is about the sane bare minimum you can go to if you want to push things. Less is asking for trouble. Note that frames, cranks, rings, and spindles do vary in how flexy they are and riders vary in habits and strength, so one can only approximate here. If you stacked the movement from a bunch of flexy things ...


9

On the Sora R3000 (and many modern cranksets) the axle, right hand crank arm and chainring spider are all one piece. The left hand crank arm fits on the splines on the axle, and is held in place by two pinch bolts. The thread you see in the hollow axle is for a plastic cap that is finger tightened to provide slight pre-load of the bottom bracket bearings. ...


8

You probably didn't remove material when you cross-threaded the bottom bracket shell in. If it's a steel frame, you can cut new (correct) threads with the correct taps. The taps are quite expensive, (they have to line up, and one is upside down, find a shop or local framebuilder who has one. Baring that you should chase the threads : grab old steel bb ...


8

The Schlumpf drives have been around for several years and incorporate a two-speed planetary gear drive attached to the bottom bracket. With the heel of your shoe, you tap a small button centered on the end of the bottom bracket to engage and disengage the planetary gear. Three models are available: a "mountain gear" version that lowers whatever other gears ...


8

You're right, you want to space it between the shell and cup. You can put spacers on either side to get the chainline right. Most cranksets come with spacers (2.5 mm is probably the most useful size for you) but if yours didn't any LBS should have a few to sell you. Something like this: http://wheelsmfg.com/bottom-bracket-spacer.html (I don't know if ...


8

Possible causes: There is "play" in the bottom bracket bearings, this could also explain the clicks. Usually this is quite noticeable, and you can check it by grabbing the crank-arm and trying to move it sideways. Usually this is not the cause for variable chain tension on singles; The chainring is "eccentric", either because of haveing been tightened off-...


8

in my experience. BB height affects stability of your ride, but mostly while standing on the pedals since you weight is then directly on the BB. but raising it 7mm may or may not make a difference in your ride. however, raising it ABOVE the axle height will make a dramatic difference in stability. BMX bikes are incredibly nimble (aka unstable) due to them ...


8

Advantages: It's cheaper to manufacture cups, even with fine surface finish and reasonable tolerances than threaded shells. Especially with carbon frames there was an issue with inserting threaded shells which needed to have perfectly parallel faces. With press-fit cups and cartridge bearings having some factory loose, the tolerances are not so strict. A ...


8

Without seeing any pictures, I think you'll likely want to replace both, but you can figure it out easily enough. Usually, the bottom bracket will be fine after a crank improperly coming loose. The bottom bracket spindle is typically made out of a hard steel and only the most miserable metal cranks are made from anything other than aluminum, so when the ...


8

I would avoid doing this. If the Teflon lube has any kind of solvent in it (which it probably does to carry the Teflon), it will break down the grease in the bottom bracket. Eventually, the grease will thin out enough that it will flow out of the bottom bracket, and No More Lube=A Very Bad Thing. If you are using a basic cartridge bottom bracket, they are ...


8

If you have an idea of what model of frame it is, it would help. Otherwise, your best bet is to take it to a bike shop and try an ISO bottom bracket (gently) to see if it fits, or measure the threads and their orientation to match to this chart. There are also universal threadless BB's like this one from Velo-Orange which skirt the issue by expanding to ...


8

Maybe double-check that there is zero debris in the threads. I ran into a similar-sounding situation and it made me very nervous given the stakes. It turned out to be small bits of finely-ground rock powder in the threads. I cleaned it with degreaser, wiped it well, blew it out with compressed air, then did all that again. After, I was able to tighten it ...


Only top voted, non community-wiki answers of a minimum length are eligible