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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2
votes
1answer
223 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 ...
2
votes
1answer
166 views

What's this noise? Is it from my crank?

I have recently been riding bmx, racing to be more specific. I ride around my neighborhood a lot when im not at the track and have noticed this loud clanking noise. I didn't know where it was coming ...
1
vote
3answers
554 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 ...
2
votes
1answer
109 views

Rat a Tat noises coming from my bottom bracket area. Please help!

I recently got my single speed frame and forks powder coated and at the same time had a number of parts replaced - bottom bracket, chain ring, chain and freewheel cassette. Really please with ...
3
votes
2answers
493 views

Replace asymmetrical BB with symmetrical cartridge and spacers?

My bike has a square taper 68mm width cup and cone bottom bracket that is wearing out. I was hoping to replace it with a sealed cartridge (shimano UN55 or similar) but then I found that the spindle ...
0
votes
0answers
223 views

Choosing the correct Bottom Bracket

I have a 2011 Commencal Supreme DHV3 Team edition and I need to replace the bottom bracket. The problem is that I am confused about what the correct model to buy is. The tech book for the bike ...
0
votes
1answer
107 views

Exchange FSA K-Force Light chainset with a SRAM RED

I'm the lucky owner of a Fuji SST 1.0 from 2010 (mounted with a Shimano press-fit bottom bracket). I would like to exchange the front chainset from a FSA K-force 53/39 to a SRAM RED 50/34. Can you ...
0
votes
2answers
437 views

FSA Omega MegaEXO Press fit BB 19mm removal (non standard BB86)

Has anyone removed a 19mm spindle (Omega) Press fit bottom bracket without destroying it in the process? I have watched http://www.fullspeedahead.tv/video/7006668/installation-of-megaexo-crankset-on ...
14
votes
6answers
27k views

How often should I grease and repack my hubs and bottom bracket?

I am commuting 7 miles a day (round trip) in all weather in New England (temperate, moderately wet climate, cold winters). Overall I am putting about 1000 miles per year on my commuter bike, a 2009 ...
2
votes
1answer
670 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 ...
0
votes
1answer
706 views

BB30 bottom bracket won't stop clicking

My mountain bike has a BB30 bottom bracket that was clicking under power. The bike is only a month old, so I figured, break in period, and I took the crank off and greased everything up with teflon ...
1
vote
0answers
243 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 ...
0
votes
1answer
456 views

MegaEXO Omega BB and Hollowtech II crank compatibility?

I have a Giant TCX SLR 2 (2014) with a FSA MegaEXO BB and FSA Omega crankset (46/36). I just purchased a Ultegra 6750 crankset (50/34), can I run it on my existing BB? If not, what BB do I need? ...
4
votes
4answers
1k views

Noticeable clicking from crankset or bottom bracket

A few days ago I began hearing a clicking noise coming from the crankset and I can also sense a slight hitch when the right crank is at its upmost position just when it's about to go down. The ...
1
vote
1answer
184 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?
1
vote
1answer
107 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 ...
0
votes
1answer
59 views

Niner Biocnetric Compatibility

Have an older Niner Air 9 Carbon that has the original Biocentric eccentric hub. Does anyone know if the Biocentric II is compatible?
1
vote
1answer
754 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
votes
1answer
207 views

Triple chainset to single chainset; BB compatability?

I'd like to upgrade the chainset on my GT Avalanche 1.0 2013 so I have no front mech or shifter and just one ring on the front; just 10 gears instead of 30. My current chainset is a Shimano M522 ...
0
votes
1answer
922 views

What are the different types of bottom brackets?

Right now I am only familiar with two types of BBs (bottom brackets): The square type on my older mountain bike. The hallowtech (SM-BB70) that comes with a Deore XT crank I bought on my newer bike. ...
2
votes
1answer
563 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 ...
7
votes
3answers
2k 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
211 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 ...
5
votes
2answers
3k 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
vote
1answer
76 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 ...
0
votes
1answer
374 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
1k 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 ...
4
votes
2answers
792 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, ...
5
votes
2answers
6k 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
608 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 ...
26
votes
13answers
91k 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
696 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 ...
0
votes
2answers
2k 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
6k 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
vote
2answers
2k 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 ...
2
votes
1answer
201 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
2k 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 ...
4
votes
1answer
482 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
2k 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
480 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
2k 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
vote
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?
2
votes
1answer
333 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
184 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
865 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
votes
1answer
131 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 ...
0
votes
2answers
3k 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
257 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
699 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
667 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 ...