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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12
votes
3answers
8k views

How do I know when to replace my bottom bracket?

With out completely removing the cranks and bottom bracket, how can I tell when it's time to replace my bottom bracket? The current symptom is a slightly 'rough' feeling when I pedal. It's not ...
0
votes
1answer
315 views

screeching noise in bottom bracket

There is a very loud screeching noise when i pedal hard on the down stroke. Be it moving off or climbing up a hill. It is not coming from the front wheel, which i originally thought came from brake ...
2
votes
1answer
650 views

Can if fit new 105 5700 cranks on my existing 5600BB?

I am refreshing my drive train. I have been running a full 105 5600 set for a couple years. I have an ultegra cassette and chain ready to fit, and I am consdiering crankset/chainring options. Is the ...
1
vote
2answers
418 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
4
votes
3answers
751 views

Crank arms are not parallel to each other. What could have caused this?

It is a cottered crank. Crank arms themselves don't seem to be bent. It is a non-cartridge style spindle. Any ideas as to why they are not lining up?
1
vote
2answers
2k 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 ...
3
votes
1answer
1k views

Will I damage anything by not replacing my clicking bottom bracket?

I have a Specialized 2010 Sirrus Sport with a sealed cartridge square taper bottom bracket that makes a clicking noise. If I don't have it replaced, will I be harming anything apart from the bottom ...
5
votes
2answers
20k views

How do I measure a bottom bracket?

I need to replace the bottom bracket bearing on my fixie. I plan to get a Shimano UN26, but I note that there are a number of different sizes. The sizes seem to be expressed as 68-110, where 68 is the ...
1
vote
2answers
721 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 ...
1
vote
2answers
2k 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 ...
3
votes
2answers
476 views

Chainline on a trek 660 fixie conversion

I am converting an old Trek 660 frame to fixie. It takes a 68mm bottom bracket and I'm putting in an SKF bottom bracket (like this) with both a BMX profile racing 110mm 46t and redline BMX cranks ...
3
votes
2answers
1k views

What road double cranksets will work with a 108mm JIS square taper bottom bracket spindle?

So far it seems like the Shimano Sante or Suntour Sprint cranksets are the only ones that would fit my bottom bracket spindle (I am hoping to keep both BB and spindle). Am I missing any possible ...
3
votes
1answer
667 views

Bottom bracket square taper (cartridge) extraction, too tight in one side

I'm getting weird noises coming from the bottom bracket (BB from now on), and I wanted to extract it to check if the problem is there or not. The guide video I used is no longer public (free) as when ...
3
votes
2answers
835 views

screeching/grinding sound when coasting at speed

2003ish Cannondale six13, all Ultegra. Frequently, but not always, when I'm coasting at a fast pace, usually down a hill, the bike will start making this hideous screeching/grinding noise. It is ...
1
vote
1answer
204 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?
4
votes
4answers
775 views

Cruiser bottom bracket is clicking and grinding

My Trek Pure Deluxe 3-speed cruiser has been making a clicking noise when riding for some time. The problem is faint, and is more felt than heard. However, it's been getting worse; it now makes a ...
1
vote
2answers
860 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 ...
7
votes
3answers
2k views

How do I stop my EBB (Eccentric Bottom Bracket) from creaking?

I have a '09 Felt Niner 29" SS with an EBB. After a thorough clean and reassembly of the BB the creaking will subside for a ride or so and then come back. Any suggestions? EDIT: the problem appears ...
3
votes
2answers
3k views

Can a bike with an internal bottom bracket be retrofitted to have an external bottom bracket?

External bottom brackets have been appearing on higher-end bikes in the last few years. Can older bikes with bottom bracket shells that come stock with square taper internal ISO 68mm or oversized ISO ...
1
vote
2answers
2k views

Does anyone have experience with Bottom Bracket Tap/Facing sets?

I'm interested in recommending my boss get the workshop in which I work a bottom bracket tap and facing set. As it's quite an investment it's important to me to know what you're getting for your ...
3
votes
4answers
4k views

Bottom bracket making noise, should it be fixed now or can I wait until regular maintenance?

My bike has been ridden 4 months / 2000 miles and is no longer completely quiet. About a month ago I noticed a whispering noise like a wire brush sliding across a cymbal. It happens on the ...
3
votes
1answer
996 views

Are Shimano Hollowtech II bottom bracket spacers unique?

I'm moving my Shimano Hollowtech II XT crankset and bottom bracket over from a bike with 73mm bottom bracket to a 68mm bike. The only problem is that I only have 1 spacer and now I need 3 bottom ...
3
votes
1answer
3k views

How hard is it to disassemble and reassemble a bottom bracket?

I ride an SE Lager. It's a pretty cheap and crappy bike. I've had to replace pretty much everything on it due to wear/breakage. The only area I haven't tackled is the bottom bracket. I can ...
1
vote
2answers
1k 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. ...
5
votes
2answers
1k views

Is the plastic sleeve optional for a GXP bottom bracket install?

I took my frame to a bike shop to have the threads chased on the drive side. When I got home, I realized that they didn't install the plastic sleeve (because I didn't give it to them). They didn't ...
6
votes
3answers
880 views

Bottom Bracket Creaking

I have a 1993 Rockhopper frame that I'm riding as a singlespeed. I have some creaking around my bottom bracket. I've just recently stripped and painted the frame, and there wasn't anything ...
6
votes
2answers
1k views

Is it possible to replace bearings in Shimano XT bottom bracket cups?

Curious if I can just replace the bearings in my existing cups or if I would need to buy new cups? If possible to replace them then what are possible high quality replacement bearings?
6
votes
2answers
3k views

How can I keep my chain from falling off the inner chainring? (specifically, from getting stuck in the bottom bracket)

I've got a mountain bike which occasionally drops the chain off the lowest gear, and then the chain gets stuck in the bottom bracket. This happens while pedalling. Once the chain is there, it takes ...
5
votes
2answers
522 views