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

learn more… | top users | synonyms

1
vote
0answers
19 views

Bottom bracket creak

I've recently bought a second hand carbon bicycle. The bottom bracket was making a creaking sound under pressure, so I took it to a shop and they put in new bearings. But after 1 or 2 cycles it was ...
3
votes
2answers
147 views

Bottom bracket replacement advice needed

I've got a Giant TCX SLR2 (2015) according to the spec sheet it has:- Crankset: FSA Gossamer Pro Cross, 36/46 Bottom Bracket: FSA MegaExo The other day I noticed the bottom bracket isn't sounding ...
0
votes
1answer
17 views

What bottom bracket fits a Truvativ E450 crank?

My bike has a crank that is so cheap that you won't find it mentioned on SRAM's web pages. This cheap crank is a Truvativ E450, and it has a square taper bottom bracket that is worn out and needs ...
12
votes
4answers
15k views

What are the benefits of external bottom brackets?

Pretty soon, I plan to replace the bottom bracket on my early 90's Sakae Litage road bike. It takes a standard, English-threaded bottom bracket. Right now I think it contains loose bearings--I was ...
1
vote
1answer
35 views

How to Remove Specialized OSBB Aluminum Inner Shell

I have a 2014 Specialized Tarmac that uses press-in aluminum inner shell cups to hold the bottom bracket BB30 bearings. These cups are affixed to the carbon frame with 2 part epoxy. (see page 2 of ...
1
vote
1answer
148 views

New bottom bracket, asymmetric cranks

I am seeking help for a "dilemma" I have with my upgraded bike. I have an old KTM Ultra Line (2004) that I have upgraded with a new chain wheel (FC-M590 48.36.26t), a Shimano BB52 bottom bracket (...
1
vote
1answer
41 views

How do I keep smallest gear on my crank shaft from contacting frame

I have an old Trek 8000 ZX that I am fixing up. I had to replace the bottom bracket and I believe I successfully did that. The bike did not have a crank set to work with so I salvaged one from a pile ...
1
vote
1answer
97 views

Can a tapered BB be installed in either direction?

I have a tapered bottom bracket on my bike, like the one in the pic. On this bike, as I bought it, the fixed cup is on the drive side of the bike, while the adjustable cup is on the non-drive side. In ...
3
votes
2answers
72 views

How do I determine bottom bracket size [duplicate]

I got a cheap old bike I fixed up and I want to install a mid drive motor but the ones I found require a specific bottom bracket size and I don't know what size bottom bracket I have. The wheels are ...
6
votes
4answers
201 views

Does (square-taper) BB spindle length affect Q factor?

I am having knee and ankle trouble on my commuting bike (1993 Specialized mtb) and this has a 73mm BB with a spindle length I haven't measured but there is space between crankarm and frame. I wanted ...
4
votes
2answers
130 views

Cutting off welded crankarm

A long time ago, when I was younger and stupider, I decided to fix my creaking crank arm by welding the bolt. Yes, I know it was so damn stupid, but I thought that was the problem. I didn't use the ...
7
votes
4answers
388 views

Help needed identifying mystery screws on 1940s tandem

My tandem has two small screws above each bottom bracket, one on each side (so four in total). I've not seen them on any other bike, and I can't figure out what they're for! Suggestions so far have ...
6
votes
2answers
34k 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 ...
4
votes
2answers
3k 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 ...
3
votes
1answer
69 views

Replaced left crank arm but still comes loose?

A few weeks ago I bought a new (albeit cheap) self assembly bike from a local store, this bike to be exact http://tinyurl.com/gw77p9t . After about two weeks use (one and a half hours of cycling on ...
0
votes
1answer
50 views

What is my bottom bracket spindle length?

I have this ubiquitous cheap Wal-Mart bike (http://www.walmart.com/ip/26-Roadmaster-Granite-Peak-Men-s-Bike-Black-Green/45089317z), which has a square taper bottom bracket. I'm trying to buy a new ...
0
votes
0answers
12 views

Bearing cap for Rotor BB30 to 24mm

I have a BB30 to 24mm adapter from Rotor. When installing the axle pushed out the bearing cap and I broke it trying to get it back in. What size replacement would I need? I'm not sure of the sizing ...
1
vote
1answer
44 views

Crank Compatibility for my Orbea Hydro 2012

I have received as a gift a set of SRAM bb30 cranks. I would like to know if they fit my 1012 Orbea Hydro and if can I use SRAM Alloy GXP Bottom Bracket to fit it all together.
0
votes
1answer
44 views

Issue with PF30 BB on Boost frame - 2-3mm crank arm clearance

I have a brand new Titanium Boost 29er hardtail. The frame uses a PF30 BB and the BB shell is 73mm wide. I have installed the recommended RaceFace cinch PF30 bottom bracket with a Race face Next SL ...
9
votes
4answers
10k 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 ...
3
votes
1answer
81 views

If chain/ BB/ casette are dead can chainrings and derailleurs still be OK?

I bought a brand new bike last May (2015 Brodie Elan) and proceeded to put 11,000km on it by November (cross Canada ride plus some commuting). Around the 11,000km mark I brought it back to the shop ...
14
votes
4answers
18k 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 ...
2
votes
1answer
66 views

Trouble removing bottom bracket

I've got an FSA MegaExo bottom bottom bracket that seems to have gone bad. I've head that FSA doesn't have the greatest bottom brackets, so I was going to try to replace it with this Shimano bottom ...
0
votes
1answer
53 views

How does this work? “Rotor BB30 to 24mm Steel Road Bottom Bracket”

I'm looking at ways to make a Claris/Tourney crankset fit a BB30 frame. I've seen that a "Rotor BB30 to 24mm Steel Road Bottom Bracket" is one of the options to make the two sizes work together. ...
3
votes
1answer
35 views

Bottom Bracket size issues

I need to replace my bottom bracket on my giant rapid 3, the BB is a FSA BB-7420ST - 116mm (68x116mm), but it's hard to found or not available. My Question is: can I use a BB in 68x115 or 117mm (...
5
votes
2answers
55 views

Cartridge bottom bracket left cup is too tight?

Is it possible for the left-side of a cartridge-type bottom bracket to be too tight ? I followed the tightening torque instructions, and now the axle is not running as freely as when the cup is less ...
3
votes
1answer
37 views

Replacement or comparable model for my current Bottom Bracket

I am currently using a old mountain bike which is using a Shimano BB -LP26 / 68 x110 Size: BC 1.37x24 I am not sure if this model is with english treading or Italian treading. I understand the don't ...
1
vote
1answer
59 views

short cranks for new Brompton JIS bottom bracket

The bottom bracket on my new Brompton is this one (I believe): http://www.sjscycles.co.uk/brompton-bb-cartridge-jis-for-spider-crankset-119mm-prod31207/ It is a JIS BB with 119 mm spindle length ...
1
vote
1answer
48 views

Are the Truvativ powerspline BBs reliable?

When I first got my Haymaker 1500 about 2 years ago the BB crank interface was the Truvativ powerspline pattern. In the first winter my left arm came loose when it was cold (-15*C or so). Since it ...
0
votes
0answers
11 views

Canyon commuter bottom bracket noise [duplicate]

The bike is 3 months old and it had since the beginning a creacking noise that comes from the BB. As far as I know it is a SRAM gxp BB...should be good.... Now I can't ride the bike because of that ...
14
votes
7answers
24k views

How to remove a crank arm with stripped threads?

A friend called me up yesterday after a mis-adventure during his attempt at a bottom bracket overhaul. He stripped out the threads on the (left) crank arm while using a Park crank puller. In a pinch, ...
4
votes
3answers
3k 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 ...
0
votes
1answer
70 views

Bottom bracket feels rough, should I replace it

My bottom bracket feels rough when I turn it with my fingers. I don't notice any problems when it's all assembled, but it's definitely not smooth like the other parts of much bike like my pedal axles. ...
4
votes
2answers
6k views

How to properly clean and lube the bearings on a sram apex bottom bracket (GXP)?

For this bottom bracket type I am not sure you can take the bearings out to lube them. How do I get grease in there. Also how do I get the old grease out? Does it even matter? I found this video (...
8
votes
2answers
7k views

How can I tell the difference between a J.I.S. and ISO square taper bottom bracket?

I have a square taper bottom bracket. How can I tell whether it is a J.I.S. or ISO taper with a minimum amount of disassembly? FWIW, it's a Ritchey from 2004. However, it would be nice to get answers ...
4
votes
2answers
125 views

Should I use anti seize for headsets and press fit bottom brackets in a titanium frame?

I have a shiny new titanium frame that I will be building up. I had the shop press in a headset and it looks like they used grease at the interface. Should they have used anti seize? I also need to ...
17
votes
6answers
38k 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 ...
0
votes
1answer
355 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 ...
7
votes
3answers
1k 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
1answer
51 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 ...
3
votes
2answers
200 views

Why is there a gap between my crank and bottom bracket?

I just fitted a Tiagra crank arm to my bike. I noticed that there was a gap between the bottom bracket and arm and was concerned whether I fitted the arm correctly. I tried to force the crank arm ...
3
votes
1answer
137 views

Bottom bracket length without knowing front chainline (fixed gear)

I'm wondering if I can find the right bottom bracket axle (or spindle, whatever it's called) with knowing my crank model (Gipiemme Dual Sprint, Velobase says BB should be 113mm) and rear chainline (I ...
4
votes
1answer
59 views

Crankshaft snags and loses resistance while cycling

I have a hybrid (18+ years old) that I use for daily commuting which has developed a problem with the cranks. Every so often (perhaps 10% of the time) when I push down on either crank arm after free-...
4
votes
1answer
85 views

Difference of bottom bracket cup materials: resin, plastic, metal

Bottom bracket cups are made of different materials. What are the pros and cons of the materials? What experiences do you have with them? The metal could be problematic due to galvanic corrosion ...
4
votes
1answer
69 views
7
votes
1answer
109 views

Does the BB axle (spindle) lengths 1:1 compare for square taper and octalink?

When measuring the axle length of a square taper bottom bracket, can I pick a new octalink bottom bracket with the same axle length? I can think of some offset added or removed by the difference how ...
3
votes
1answer
253 views

How do I convert a Shimano Selecta to something more modern and quality?

I have created a single speed bike out of a 1982 Helkama Kulkuri. The only part that is a mystery to me is the bottom bracket (BB). It seems it is an interesting and easy to work with Shimano Selecta. ...
5
votes
1answer
1k views

BB92 (Shimano bottom bracket) with SRAM 30mm crankshaft (X01 or XX1 BB30)?

The frame that I want to build has BB92 bottom bracket hole. The drivetrain I want to use is 1x11 SRAM XX1 or X01 with 30mm crankshaft (BB30)(edit: also available GXP). There are ways to fit it - ...
4
votes
1answer
287 views

Why is my electric bike 'clanking' under load?

I have a Giant Esprit Twist Power electric bike, which apart from not having nearly enough words in its name also has a problem related to the crank. When I put a lot of load through the pedals there ...
0
votes
2answers
363 views

Loose pedals on Norco MTB

Just replaced my pedals on a very old Norco MTB. I noticed while working on it that the whole peddle structure is wiggling from side to side is this normal ? I took the plastic caps off the base to ...