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

5
votes
2answers
145 views

Toothed plastic cup on bottom bracket got sheared off - still removable?

I messed up. I wanted to switch out the bottom bracket on my bike. When I tried to do that the toothed cup on the left side (non-chain side) sheared off. The entire thing is now plain with its housing....
2
votes
2answers
66 views

Minimum space between square taper crank and bottom bracket

I upgraded to a new square taper crankset on a single-speed drivetrain and now the gap between my crank and the bottom bracket is bigger. That's because the cranks taper shape is different from the ...
1
vote
2answers
51 views

Regreasing pressfit bottom bracket

I strongly suspect there's creaking coming from my pressfit BB on a road bike. What I don't know is whether the pressfit BBs is reuseable, so once I remove and regrease the whole thing in there, can ...
1
vote
1answer
43 views

Scott Addict R2 2008 crankset replacement

I want to replace crankset on my Scott Addict R2 2008. Current crankset is Dura Ace 7800. If I looked correctly then currently I am using BB SM-BB71-41. New crankset will use BB386EVO. Which BB do I ...
1
vote
3answers
127 views

Bottom bracket maintenance - is it a thing?

Previously when I've had annoying noises from my bottom bracket I've simply discarded it and bought a (cheap) new one. But the last time I replaced it I got a great offer and splashed out a little ...
5
votes
2answers
291 views

Ideal distance between chainring and chain stay

I am building a single speed bicycle, and I have most of the drivetrain parts: Rear hub 18T rear cog (40-40.5mm ideal rear chainline -- wheel undished) 1/8" chain crankset with 40T chainring I used ...
1
vote
3answers
93 views

BB spindle length/chainline for re-used Shimano FC-M391 chainset

I'm trying to rebuild an old Univega MTB. Primary goal is to build a good or decent bike from used parts. The crankset+bb that was on the bike when I got it was really worn out. I unscrewed it and ...
1
vote
2answers
94 views

Home made bottom bracket plastic sleeve

I want to make a plastic sleeve from a water bottle, for a classic cup and cone bottom bracket, to protect against moisture and impurities that may run down the seat tube. How do I know the proper ...
1
vote
2answers
113 views

Loose thread (stripped) tapered bottom bracket frame connection

The threads in the MTB frame that is supposed to hold the bottom bracket lock rings were very loose and it can't hold the bottom bracket in place. The previous bike owner tried to apply Teflon tape in ...
3
votes
1answer
66 views

Self extracting crank preload

This question got me wondering about self-extracting cranks: What bottom brackets are compatible with Miche Evo Max cranksets (self-extracting type)? Where I've seen them on cartridge bottom brackets,...
0
votes
0answers
72 views

What bottom brackets are compatible with Miche Evo Max cranksets (self-extracting type)?

I'm in need of a Miche Evo Max bottom bracket and they are not readily available where I am. The hub resembles Hollowtech but it has an internal aluminum spacer to limit bearing side load, as the left ...
1
vote
2answers
49 views

Surly Pugsley bottom bracket replacement

Does the bottom bracket on Surly Pugsley need to be replaced with a like for like surly part (100mm external bottom bracket) or will any 100mm external bottom bracket be compatible..? The surly part ...
4
votes
1answer
124 views

What are the metal shavings in my bottom bracket from?

I opened up my FSA BB30 bottom bracket to find metal shavings all around. I opened up the bracket to try to find the source of a creaking sound, I’m guessing this is it - but I’m not quite sure what ...
1
vote
1answer
412 views

What is the difference between Shimano BB71 and BB72 bottom brackets?

I often see the Shimano BB71 and BB72 press fit bottom brackets listed on stores alongside one another, like here for example, so what's the difference? Are they both the same geometrically? Is one a ...
3
votes
2answers
459 views

Wrench to be used with a bottom bracket tool?

It looks like a wrench with a cup at the endpoint. I was wondering what is this tool called and whether it's meant to be used by itself or in combination with a bottom bracket tool, like the PT BBT-22,...
1
vote
1answer
62 views

Remove chain guard from bottom bracket

What tool do I need to remove the black plastic cup that is holding the metal holder for my chain guard? I can rotate the metal part but the cup is not moving. While googling I could not find anyone ...
2
votes
1answer
277 views

Using spacers on crank spindle instead of bottom bracket when fitting HollowTech MTB crank to road bb

HollowTech road BB is 68 mm wide and fits a road crank without spacers. Hollow tech mountain BB uses up to 3 x 2.5 mm spacers. Hence crank is designed to be used with 75.5 mm wide bottom bracket ...
3
votes
1answer
146 views

Unusual bottom bracket shell

I broke my bottom bracket axle a few days ago, and when I removed the crankarms I discovered my old bike is using a cup and cone bottom bracket but more importantly the bracket shell is a bit odd. It ...
5
votes
1answer
131 views

The bolt of my pedal's crank arm broke, what could be the causes?

It broke while as I started pedaling when a redlight turned green. In the pics it is possible to see that basically the metal broke! Was it just a poorly constructed product or are there some common ...
1
vote
1answer
48 views

What tool do I need to press fit a “Spanish” bottom bracket?

I bought a BMX style bottom bracket called a "Spanish" bottom bracket for a dirt jumper. Instead of using a hammer and a block of wood, I would like to do it correctly with a press... however, I'm ...
3
votes
2answers
439 views

Which removal tool do I need for this 16t bottom bracket?

The bottom bracket that you see in the picture has a strange 16 teeth profile (3-1-3-1-...). I had this bike built a few years ago and I don't remember what model the BB is. I wonder what removal ...
2
votes
1answer
38 views

Press fit bottom bracket causing bearings to bind

I have a carbon Cannondale mountain bike with what appears to be a PF30 or PF30A bottom bracket: two 6806 bearings pressed into cups, which are pressed in turn into the frame. With the bearings and ...
4
votes
1answer
139 views

What is this bottom bracket

We were doing a volunteer bike repair clinic and came upon this bottom bracket that I've never seen before. It was on a trials bike and the crankset was destroyed but we couldn't find any way to ...
6
votes
4answers
392 views

How can I remove the stripped plastic cups of a bottom bracket?

I have a 2 frames with FAG bottom brackets (can't tell the exact model from the outside, but something like this): (datasheet here) in various states of destruction Bike 1 I didn't have the tool so ...
1
vote
1answer
89 views

Building a Dirt Jump Bike - Spanish Bottom Bracket?

I'm putting together a Deity Cryptkeeper and confused about which bottom bracket to buy... The specs say: spanish 73mm Bottom Bracket Does this mean 73mm wide and 37mm diameter bearing?
3
votes
2answers
111 views

What is causing this sound?

https://vimeo.com/270962821?utm_source=email&utm_medium=vimeo-cliptranscode-201504&utm_campaign=28749 Guys at the bike shop recommended a bottom bracket change would fix the problem however ...
1
vote
1answer
59 views

2003 Klein Attitude comp bottom bracket change type

I have a 2003 Klein Attitude Comp, and I want to put a crankset I have on it. However, the crankset is square taper and the current bb is not. Does anyone know what size square taper bb can go in ...
3
votes
1answer
154 views

Can not replace Shimano Octalink with 105 Crankset

Hello! I am trying to upgrade my bike’s Octalink BB 118 mm to a 105 5600 BB and crankset. The problem is I can not make the plastic pin of 105 left leg fit the hole. I think the axle is too short or ...
4
votes
2answers
125 views

Bottom bracket conversion with rare cups

I'm asking this question as I'm interested in the community opinion in the idea of "am I taking the right path" or "is there a better way". tl;drl; - scroll to the bottom, please. Namely, almost ...
2
votes
1answer
57 views

Can you replace bottom bracket without removing chain or front derailleur?

Can you service (i.e. fully remove and replace) a Square Taper English Threaded Bottom Bracket without removing the chain and/or front derailleur? Ditto for other BB types if the answer varies by BB ...
3
votes
3answers
290 views

Is movement in my bottom bracket an issue which requires attention immediately?

TLDR; my bottom bracket has movement when it shouldn't but no other issues / sounds / clunking. If I'm riding a few miles a day, is this likely to break catastrophically, or will it last another year ...
0
votes
2answers
29 views

Changing the Crankset on a Stevens Cityflight

I bought my first used Roadbike a few months ago, after some intensive riding the shaft was displaced a few mms to the left leaving the right side with less tooth-length which subsequently lead to the ...
-2
votes
1answer
176 views

There’s an pulsing feeling when pedaling

I sometimes feel what I can only describe as a pulse when pedaling my Boardman Comp road bike. It is intermittent and is not accompanied by any noises. I suspect it's the bottom bracket but I'm not ...
1
vote
3answers
303 views

110mm crank on 73mm BB shell

I have a roadbike with a 73mm BB shell and I recently bought a Tiagra compact crankset that has a 110mm bolt circle length. However, I can't get enough of it to come out the other side to properly ...
1
vote
2answers
707 views

BB height when change 29er wheel to 27.5 wheel

I have a 29er frame Specialized Camber Expert Carbon EVO with 330mm BB height with 120mm 29er fork How much with the BB height be altered if I change to 650b wheels and 27.5 140mm fork? EDIT The ...
2
votes
2answers
238 views

Bottom Bracket on a Trek CrossRip Comp 2016?

I'm trying to change my crank set from a FSA Vero 602 50/39/30 set to a FSA Gossamer Pro 386ABS 48/32. I have the new crank set but I need to know what my bracket shell standard is. I was wondering ...
0
votes
2answers
141 views

Compatibility to BB86

I have a second hand frame circa 2014 that measures about 74mm across at BB. I'm fitting an Ultegra crankset. Shimano states I need a BB94-41 for a shell width of 86mm ????? Am I reading this wrong?...
3
votes
1answer
77 views

Metal sheet inside bottom bracket on frame: can I remove it?

I have an old frame (60's vintage), into which I'm trying to install a modern sealed cartridge bottom bracket. I've got a bog-standard Shimano BB-UN55 with diameter 68mm, which should fit the frame. ...
0
votes
1answer
114 views

Can I replace Record bottom bracket with Shimano?

My Gios Torino carbon bike uses a Record bottom bracket, but those are so hard to get in Nigeria where I live. I've seen a Shimano bottom bracket but I don't know if it will match with the threading ...
2
votes
1answer
399 views

Spindle diameter on the FSA Gossamer TT MegaExo crankset

What is the spindle diameter on the FSA Gossamer TT MegaExo crankset? 24 mm or 30 mm? I can't find a direct answer anywhere. I have seen MegaExo described as 19 or 24 mm, but "Gossamer" as 30. I'm ...
2
votes
2answers
415 views

QUARQ DFour installation on Shimano bike

I'd like to replace my Ultegra 6800 crankset with QUARQ DFour powermeter. But I don't know how to choose between BB30 and GXP versions. I have Shimano Pressfit SM-BB92-41B bottom bracket. Do I need to ...
0
votes
1answer
75 views

Why won't the front derailleur change into the largest gear after changing cranks?

We changed to a longer set of cranks (same make), and have tightened the crank as tight as it will go without stripping. There is still a space of approx 2mm between the crank and the lip on the ...
2
votes
1answer
433 views

Single to double chainset conversion

Can I change a single chain ring to a double? I have an old steel frame with a narrow bottom bracket shell 66mm and a single 50 tooth chain ring. I would like to add a 36/40 inner and want to know ...
1
vote
2answers
50 views

Options on converting away from the cotter pin cranks on bsa wayfarer bicycle

The shell diameter I just measured it at 70mm but am unsure about the threading. However considering both the fixed and adjustable cups needed a hcw11 to remove, am told it's likely it uses raleigh ...
1
vote
1answer
65 views

Removing lockring/ cups off head tube on vintage BSA bike

I finally managed to get the SOB crank arms off the bike. It took a spare seat post and 100mm enginners vice, and perseverance. Anyway I'm on the home striaght now in terms of getting the bloody ...
3
votes
2answers
104 views

getting the crank arms off an old bsa bike

So I'm resuming work on restoring a bsa bike for my sister. The first thing I need to do is strip it as it's in need a of new paint job. I'm having trouble removing the crank arms. They appear to ...
3
votes
1answer
620 views

BB86 bottom bracket with BB386 crankset?

This is the markings on my bottom bracket. Will it fit BB386 crankset like the FSA Powerbox? http://www.wiggle.co.uk/fsa-powerbox-alloy-road-abs-chainset/?curr=SEK&dest=14&prevDestCountryId=...
1
vote
1answer
86 views

Using normal square bottom bracket on crankset designed for E type?

I am building a LHT 26" and I am planning to use a square taper bottom bracket. Also want to have triple chainring with a small chainring 22T so bought the Shimano Alivio FC-M430, about the best ...
0
votes
1answer
436 views

Canyon Strive AL 6.0 - SRAM GXP or a Pressfit GXP bottom bracket?

Does the 2016 Canyon Strive AL 6.0 Race have a SRAM GXP or a Pressfit GXP bottom bracket?
6
votes
1answer
243 views

Niner Biocentric I eccentric bottom bracket adapter won't budge

Niner Biocentric is the asymmetric bottom bracket adapter for a single speed. Below is the II. I have the I. I could not find a picture of the I. It is stuck. I have tried penetrating oil for ...