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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2k views

How to upgrade a dust cap?

For all you mechanics out there I am sure you hate these things. Dust caps are the bane of my existence. They are cheap and bend easily. I want to get a better sturdier one for a bike I am working on. ...
2
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2answers
289 views

How many spacers I can put on a Shimano hollowtec 2 BB for a 68 mm BB shell

My bottom bracket shell is 68 mm English thread. I put a 1 mm spacer on the drive side BB to move the chain rings further away from the frame, so to prevent the chain rub against the inside of the ...
2
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2answers
249 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 ...
2
votes
1answer
940 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 ...
2
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1answer
416 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 ...
2
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1answer
760 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 ...
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1answer
285 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 ...
2
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1answer
182 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>- ...
2
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1answer
472 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 ...
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3answers
519 views

I unscrewed the lockring, and *both* BB cups rotated - what's going on?

I'm fixing up an old tandem, and the cup-and-cone bottom bracket at the front sounds very gritty, so I picked up my c-spanner and applied it to the lockring. With a bit of effort, left cup and ...
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2answers
778 views

Bottom Bracket Size for Specialized Roubaix Elite C2 2009

I think my bottom bracket has worn and I would like to replace it. I was looking at the Shimano 105 BB. BikePedia lists the size as 68mm, which is fine, but there seems to be another dimension. I ...
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0answers
323 views

Serial numbers on bottom of a pedal crank housing from a 50s era Schwinn?

Can someone please explain what these three numbers mean on the pedal crank housing? I believe this to be the pedal crank housing from a 1956 Spitfire Ladies Bike. The Schwinn Serial reads M0D502 ...
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1answer
2k 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 ...
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2answers
3k views

Will a hollowtech shimano BB fit a bike which currently has an octalink bracket?

I have a mongoose otero elite 2008 and the crankset is broke (wobbling) It's also bent, so time for a new one. I currently have a nice shimano deore crankset from an old bike, but it uses a different ...
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1answer
157 views

Is anyone aware of specific problems with Vanmoof cranks/bottom brackets?

I have a 2013 Vanmoof 5.1. I had it serviced recently by Vanmoof in Amsterdam and when I got it back, it was riding wonderfully—everything felt smooth and "free", like every little bit of power I was ...
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3answers
813 views

Replacing bottom bracket on 98 trek 820

I'm trying to replace the bottom bracket assembly on my 98' trek 820. The current one grinds and needs replacement. The bracket that came in it is a shimano bb-ct92. I've looked online and can't ...
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2answers
792 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 ...
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3answers
2k 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 ...
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3answers
980 views

Noise from crankshaft spindle and then the pedal falls off

In the last 6 months I have been getting really bad noises, creaks, clunks, etc coming from somewhere around the spindle connecting to the crankshaft. Every time I put pressure down on the left hand ...
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2answers
590 views

how to replace a bearing on BB7800?

Friends, Do anyone of you know on how to replace a bearing on BB7800 ? Do I need a special tool ? or a screw driver, and hammer would be enough to push it out ? Thanks
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2answers
221 views

How much assembly is required when an LBS orders a bike?

I'm looking to order a Marin Lombard Elite from my LBS but I want to replace the FSA BB and crankset with Shimano or SRAM parts, and change to a 52/36. When my LBS orders it, does all of that come ...
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2answers
188 views

BB Lockring won't completely tighten

I am trying to put the lockring back on my BB after adjusting it to reduce the play, but I am unable to full tighten it. I can hand tighten the lockring, but as soon as I try to use my hook spanner to ...
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1answer
245 views

Tool for shimano bb-un26 Bottom Bracket

What tool do i need to dismount a shimano bb-un26 bottom bracket? Will a Park Tool BBT-22 work?
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2answers
4k 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 ...
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2answers
856 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 ...
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3answers
2k 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?
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2answers
63 views

Using Loctite for integrated head set and bottom bracket installation

I'm in the process of building up a new bike from scratch. Since the last time I have done this many things have changed, reading varios forums and watching numberless videos on YouTube have not ...
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1answer
68 views

Bottom Bracket issues

So I took the old bottom bracket out of my hybrid frame, FSA Platinum ISIS Bottom Bracket 68 x 118mm. I then replaced with a Shimano BBUN55 Square Taper 68 x 11.8cm. Then realised that this was a ...
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1answer
63 views

A gap in the hole when inserting JIS square BB to a Truvativ Crank

I push the BB inside a crank hole without any tool but I expect a few milimeters gap. The Truvativ crank definitely uses JIS interface, but the question is: DOES the gap make any problem? or is it ...
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2answers
373 views

How do I know what is the right bottom bracket for my old road bike?

I've got an old road bike. I'm not exactly sure what the frame is as it was repainted. I've reason to believe the that bottom bracket is wrong because the crankset ring is too close to the chainstay. ...
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1answer
83 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 ...
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1answer
1k 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 ...
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1answer
292 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 ...
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1answer
241 views

How can I use a small Shimano BB on any frame?

I have a Shimano BB-ES25 bottom bracket and 45T crankset that was removed from a Giant-CRX City with an eccentric hub (it had Shimano Alfine internal hub gears). They have literally never been used, ...
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2answers
810 views

Koga touring bicycle bottom bracket loose, does it need replacing?

I have a 2009 Koga Signature high-end touring bicycle (internal hub gear, hub generator, half-open chainguard, ...). I'm cycling around 100 km/week (8½ km one-way commute) plus trips, so I've probably ...
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2answers
1k views

Cartridge equivalent spindle length for Shimano BB-6207 116 mm Cup and Cone Bottom Bracket?

I'm building up an old Terry bike and will likely pick up a NOS Shimano 600EX FC-6207 crankset. The corresponding bottom bracket for this crankset is the 116 mm BB-6207 cup and cone. However, given ...
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1answer
22 views

Bottom Bracket - Drive Side is Stuck, what to do please?

I'm trying to remove a sealed cartridge BB. I've removed both cranks and the non-drive side (plastic) came out fine. The drive side is stuck solid - I know it's reverse thread on the drive side and I ...
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1answer
65 views

What is an attached bottom bracket?

Reading the specifications of a Merida Reacto 500 (2015) I noticed that at the bottom bracket is Attached, I only ever read about brackets threaded in the frame or press fit brackets.
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1answer
263 views

Giant Defy 2 Bottom Bracket

I'm considering upgrading to an Ultegra groupset, found a very good price online, but I do not know what bottom bracket is in my bike. I have a 2015 Giant Defy 2, aluminum frame, and to me, this looks ...
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1answer
282 views

Praxis Bottom Bracket Performance on BB30 Frame

I'm looking at upgrading the crank (stock FSA to Force 22) and getting a Praxis BB for my Cannondale CAAD10 BB30 frame. http://www.praxiscycles.com/product/conv-bb-sramgxp-isis-2/ It seems like ...
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1answer
184 views

Q-factor of external bearing BBs

Seems to me that the Q-factor for an external bearing bottom bracket will be greater than that of an equal size (say, 68mm road bike BB) cartridge bearing. Is that the case?
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1answer
126 views

Are Hollowtech II bottom bracket normal?

I've just installed a brand new Ultegra 6600 crank/bb on my brand new frame. Everything is fine and properly installed, but the crank doesn't rotate as freely as a square taper BB. The bike is not yet ...
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1answer
888 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 ...
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1answer
836 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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1answer
929 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, ...
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2answers
351 views

New rocky mountain soul 29 making creaks by the bb

Not to sure what it's coming from I don't have the tools to take the crank off or adjust the bb. The funny thing I don't get is that the creak is gone the next time I ride my bike then when I may go ...
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1answer
260 views

What Bottom Bracket for a 2007 Rush Hour frame?

The stock rush hour bottom bracket is a FSA BB-7420. Would a Shimano BB-UN54 that is 68 X 107mm work in that frame?
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1answer
331 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 ...
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2answers
4k views

Stationary bike “clicks” when pedaling - crank axle is moving sideways. How can I fix this?

I've got this stationary bike, a York C202, which has developed a problem - namely it "clicks" when pedaling. This is highly annoying, as there's nothing I seem to be able to do about it. I diagnosed ...
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1answer
242 views

Crank fell off square taper BB. Should I replace bottom bracket

After years of use and multiple retightenings my crank will fall off my bike about once a week and definitely needs to be replaced. I believe that the square hole of the crank has expanded to the ...