The part of your bike that contains the axis the cranks arms spin 'round. (The crank arms are where the pedals attach.)

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1answer
135 views

Selecting a compatible BB: spindle offset

Replaced Shimano Bottom Bracket, now front derailleur won't shift to largest gear How do I measure a bottom bracket? I thought the only thing that mattered when replacing a bottom bracket ...
6
votes
3answers
666 views

Creaking bottom bracket

I have a Trek 3900 Mountain bike that had a serious creaking problem whenever I would pedal. I found that the ring that holds the Shimano sealed bearing was really loose. I tightened it up and it ...
2
votes
2answers
38 views

Creaking From Bottom Bracket [duplicate]

I'm not too familiar with the correct terminology for bike parts so please bear with me. I recently bought a mountain bike and have started to notice a loud creaking sound coming from the ...
4
votes
2answers
267 views

How to replace old style cotter-pin bottom bracket with a modern one?

I have an old 1950's English bicycle with cotter-pin style bottom bracket like this: I find the cotter pins fail fairly regularly and are hard to replace correctly. I was wondering if it's possible ...
1
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1answer
39 views

How do I remove a bottom bracket?

I have managed to remove the threaded locking mechanism of this bottom bracket. However, I can't get the bracket out. I have tried to just bang it out, but it doesn't move. I don't know what else to ...
2
votes
3answers
299 views

Expected chainline from 103 mm bottom bracket to 107 mm bottom bracket?

Frame Windsor - The Hour Hub Width - 120mm Stock Bottom Bracket Sizing - 68 x 103 mm Miche Bottom Bracket Sizing - 68 x 107 mm Miche Crank Set Requirements - 68 x 107 mm bottom bracket ...
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0answers
34 views

Replacing SRAM Red chain set with Ultegra - bottom bracket?

I have a cyclocross bike with an Ultegra 6700 chainset and a road bike with SRAM Red. I'm looking to get a Stages Ultegra power meter (left crank arm mounted) that I can swap between both bikes. This ...
0
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1answer
38 views

Will this crankset fit my bottom bracket?

I've got a 2004 Trek 4300 that I need to replace the crankset on. I was able to look up the bottom bracket size here and see that it's a 73x122.5. I'd like to buy this crankset but I'm not exactly ...
4
votes
1answer
105 views

What went wrong with my bottom bracket spindle length calculation?

Here's the facts: My bike frame requires a 70 mm Italian threaded bottom bracket I'm going to use a Nuvinci N360 IGH which requires a chainline of 49 (± 0.5) mm. I have Andel fluted cranks, which ...
0
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1answer
106 views

Are these compatible bottom brackets?

I have a LeMond Big Sky SLT & an Opus Triton. Every bikepedia-esque site I went on said they had incompatible bottom brackets. When I actually read the brackets today the LeMond has a BSA. The ...
4
votes
2answers
379 views

Why does the chain tension vary as pedals are turned?

I have a new single-speed bike (after purchase this year, it was unused in a garage for a few months), but as I turn the pedals, the tension in the chain varies noticeably. What should I check, ...
3
votes
0answers
58 views

Do Miche bottom brackets require a special tool, or is this one damaged?

I just bought a Miche Primato bottom bracket and tried installing it using Park's BBT-5 (the same tool I used to remove the previous bottom bracket, also Miche, but from 2008). The BBT-5 fit into the ...
5
votes
2answers
5k views

Does my bottom bracket need replacing?

About two months ago I bought a Boardman HT Comp. Today I took it into my local bike shop for a service. While I was in the shop one of the technicians had a quick look at it and told me that my ...
5
votes
2answers
321 views

Bottom bracket removal, what is this part?

I have a new (old) bicycle, and I am in the process of disassembling it. I arrived to the bottom bracket (with a cottered crank), and unscrewed the ring without problems, but then I'm faced with a ...
21
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13answers
48k views

Creaking from cranks/spindle. How to fix?

Recently the cranks on my bike started to creak. I checked with my usual "bike-bible" Park Tool. They recommended dis-assemble, lubricate, re-assemble. So I did that. Remove cranks. Remove spindle. ...
1
vote
1answer
150 views

Bottom bracket mysteriously squeaking

Somewhere from the non-drive side of the drivetrain is coming loud squeak when I pedal hard. The story is long. First I threaded the BB-ES25 incorrectly, and had to spend half an hour with a file to ...
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2answers
144 views

Lower vs. Taller Bottom Bracket Height

The bottom bracket height on some bikes can be adjusted 7.0mm by flipping a "chip" in the shock mount linkage. This also effects head tube angle by 0.5 degrees. Theoretically speaking, What are the ...
2
votes
4answers
3k views

Cross threaded/stripped bottom bracket

I installed a new sealed bearing in my bottom bracket. Unfortunately after tightening it most of the way, it jammed and I realised I'd cross threaded it. I then removed it and reinstalled it. It ...
1
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2answers
118 views

Broken bottom bracket? Pedals are pretty loose

Unlike the rest of the broken bottom bracket questions, my bottom bracket does not make any noise or feel like anything is grinding. There is about 1/2cm of play left to right that i can see on the ...
1
vote
2answers
780 views

Removing bottom bracket from 79 peugeot frame

I would like to remove the bottom bracket from an old french peugeot race frame. I believe the frame was built in 79 judging by the decals and stamp on the bb. The bottom bracket and spindle at the ...
2
votes
1answer
84 views

Older Motobecane conversion

I recently acquired an older blue Motobecane Mirage with a great frame and paint. I have stripped it all down and salvaged everything I can (frame, front wheel, handlebars, front brake) but now I'm ...
3
votes
4answers
1k views

Bottom bracket with built-in internal hub - does this exist?

I've heard that one can install a bottom bracket that has what is essentially a built-in internal hub, giving one the ability to add a virtual double chainring where there's only one. This would be ...
3
votes
1answer
125 views

How do I tell if I've correctly installed a press fit bottom bracket?

So I bought a Chris King PF30 bottom bracket and pressed it in using a bearing press along with the bushings that came with the Park Tool bbt-30.3. Using the bearing press I pushed both cups in ...
4
votes
1answer
208 views

What tools do I need to replace my bottom bracket?

I have an old 2001 Schwinn Homegrown Pro that I want to upgrade to a 10-speed drivetrain. I'd like to do it myself as a learning exercise, but I'm not sure what kind of tool I need to remove the old ...
3
votes
2answers
268 views

Do I need to face my new frame?

I just purchased a new aluminum MTB frame. The headset is a standard "NECO, 142, 1-1/8” AHEAD". The BB is ... I'm not sure, but is internal and threaded. How do I determine if I need to face or ream ...
3
votes
1answer
192 views

Can I measure my bottom bracket size without removing the cranks?

I don't have a LBS (there are BS, but not L), so I generally order everything I need online. I need to replace the bottom bracket on my commuter bike, which I know is a VP-BC73 but that BB's available ...
1
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3answers
1k views

How long does it take to replace bottom bracket bearings?

How long does it take to replace bottom bracket bearings? Is there anything that can make the procedure take more or less time? How does the type of mechanism affect repair time?
2
votes
1answer
136 views

How can I prolong the life of my bottom bracket bearings?

I have a bike with Campy components. I've found I need to replace the bottom bracket bearings annually, which is expensive and inconvenient. I do less than 2000km per year on it, largely through ...
4
votes
1answer
139 views

If external bearing BBs are better, why use traditional ones?

Related: What are the benefits of external bottom brackets? An outboard BB includes any BB which uses the same BSA or Italian threading as older style BB's, but places a larger bearing ...
1
vote
1answer
234 views

How tight should a threaded BB be?

I have an english-thread, octalink Shimano bottom bracket, and a new frame. The frame has been faced before painting. I am not sure the BB is compatible with the frame. When trying to install the ...
0
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1answer
113 views

Soft “Thunk” in the crank

I have a one month old Citizen foldable bike and I have noticed a soft "thunk" when turning the crank. It sounds the same whatever gear I am in. It also seems to go away for a short while if I stop ...
2
votes
0answers
153 views

What types of BB-axle to crankarms interfaces are there?

On the lowest end, we have the taper/square interface. I believe it is standard i.e. there are no variations in the sizes. image property of VP Components USA Then there is the octalink. Actually ...
0
votes
2answers
736 views

New frame bottom bracket and crank compatibility and general stupidity!

I recently bought a Scott CR1 SL 2012 frame to replace a crash damaged frame on my 2009 Boardman Team Carbon road bike. The intention being to move as much as possible across from the old bike on to ...
2
votes
1answer
165 views

Yet another stuck BB. Help me save my frame!

So I have two bikes and a year ago I went through the challenge of unscrewing a stuck BB. The solution was to put the tool in a vice and twist the frame around it. Today I have an even more difficult ...
1
vote
2answers
228 views

How to judge BB height visually and the effect on handling?

Is it possible by viewing a bike frame to tell roughly what the handling of the bike is going to be? This current question is about bottom bracket height in the above mentioned respect. I have ...
0
votes
1answer
167 views

Can't get the drive side bottom bracket cup out

I have an older Raleigh frame that I converted to a fixed gear and the bottom bracket cup on the drive side has been painted over a few times and I can't get it out. This is the type of cup (the one ...
0
votes
1answer
106 views

Windsor - The Hour - Bottom Bracket Dimensions

I'm looking to replace the bottom bracket in my Windsor "The Hour" since I'm buying a new crank set for my bike. What are the dimensions for the bottom bracket: both shell width and shaft length? I ...
5
votes
2answers
537 views

How should I prepare a carbon frame when I want to swap in a new bottom bracket?

My four-year-old, carbon-framed road bike has developed a case of creaky cranks. I only hear creaking when pedalling hard, when I pedal more softly it just sounds like it has always done. Given the ...
3
votes
2answers
450 views

How can I remove the bottom bracket from this old road bike?

I need some help removing this bottom bracket. I am obviously no mechanic, and watching several videos on youtube I found nothing that could help in this specific case. Basically after removing both ...
1
vote
2answers
285 views

Bottom bracket cup doesn't fit on non drive side

I'm replacing the crankset and bottom bracket on my old steel frame road bike, which looks like this one, so I'm guessing it's from around 1985. I picked up a 68 mm square taper bottom bracket and ...
2
votes
1answer
129 views

Raleigh AT20 series bottom bracket affects derailleur

I took out the bottom bracket to clean it etc taking off the pedal shafts etc - and when it came to putting it back - the front derailleur was well out of adjustment - Have I done something wrong>- ...
1
vote
1answer
254 views

Shimano Ultegra Bottom bracket replacement with Dura-Ace

The bottom bracket on my Van Nicholas Astraeus is a creaking when going up hills. It's already been tightened recently, yet seems to creek more and more lately - probably due to the mileage (many, ...
0
votes
0answers
53 views

BB30 Bottom bracket with GXP Shim

I have a BB30 bottom bracket, and bought the Wheels Manufacturing shim so I can use my GXP power meter. When I used the dust shields that come with the BB30, it seems like the crank spindle isn't long ...
2
votes
1answer
890 views

Replaced Shimano Bottom Bracket, now front derailleur won't shift to largest gear

OK, so in my quest to get my old Trek 7000 ZX MTB running again after a long retirement, I am having an issue with replacing the bottom bracket. The bike came with a Shimano LP25 that is marked BC ...
2
votes
1answer
224 views

Italian bottom bracket Shimano BB-6400 fixed cup tightening - what tool?

All, I have a Shimano 600 Italian-threaded bottom bracket (BB-6400) and after riding with it for a few weeks, the fixed cup is loosening. I've since read up about Italian BBs and learned that the ...
0
votes
1answer
143 views

bottom bracket Stronglight JP400 equivalents

I need to replace my bottom bracket cartridge because it is knackered. After a bit of reading it seems that there may be many types of cartridge variations (axle lengths, threads, size of square ...
2
votes
3answers
352 views

Failing to unscrew BB - what now?

I have an external bearing BB, that I need replaced (It is quite badly rusted). I opt to do the repair myself. The bike is a Specialized Hardrock, the crank arms are SR Suntour. Having removed the ...
2
votes
1answer
170 views

Thinking of getting a new chainset

I've decided to get a new chainset as my current 38T Nexus is giving low speeds with my Alfine 8 speed hub. I have my eye on the 45T Shimano Alfine chainset. Currently I have a square taper bottom ...
2
votes
2answers
1k views

What sort of bottom bracket does a Trek 1.5 2011 take?

My bottom bracket is on its way out.. No longer getting smooth rotation even without chain attached. I was wondering if anyone knew what sort of bottom bracket the frame supports? I've googled but the ...
5
votes
2answers
746 views

Swapping cranks, but the new crank is wider, how do I compensate for this?

I was swapping the cranks and bottom bracket on my karate monkey from a Truvative stylo crankset (Mountain Double, GXP bottom bracket) to a Race Face Evolution DH (Mountain Triple, Race Face bottom ...