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Questions tagged [bottom-bracket]

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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1answer
33 views

Bottom bracket replacement bearing

I have been looking for a press-fit bottom bracket replacement bearing for a Giant Fastroad SLR1 (2016 model). The markings on it identify it as an FSA 19mm diameter, that is the spindle is 19 mm i ...
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2answers
141 views

Can you get a threaded bb30?

I've a threaded shell, but i have got bb30 cranks, can you get threaded bb30 bottom brackets that the it can with fit the bb30 cranks?
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2answers
1k views

What type of crank fitting is this?

I have an old road bike I want to get a single speed crank for but don't know what fitting the bottom bracket has.
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1answer
34 views

Wilier Zero9 bottom bracket

Im trying to investigate what type of bottom bracket has by Wilier Zero9 road bike. Looks like some pressfit but Im Not sure, inner bearing width has 25mm. I have Shimano Ultegra 2x11 6800.
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2answers
77 views

Old Sears Simpson bike bottom bracket replacement

Got the pedals out, but I'm struggling with both cups. I don't know which way the threading goes either. The bike was made in Poland, pretty old. Anyone know what I could do? I have a flat-shaped ...
3
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2answers
48 views

Quarq Dfour Fit Problem

I recently buy my first Quarq Dfour power meter to replace my crank Shimano Ultegra 6800. but I have the problem that the quarq spindle its too short ( 106 mm quarq vs 109 mm shimano ultra ). I don't ...
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3answers
70 views

Bottom bracket replacement

I have an old '89 Trek Singletrack 950 with the original Shimano Mountain LX group bottom bracket. I'd like to replace the bottom bracket with something new. Can anyone help me determine what will fit ...
3
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2answers
58 views

Damage to bearings from press fit bb removal?

Is it possible to remove the bearings from one bike's bb and put them on to another or would using a tool such as the Park tool bbt 90.3 damage them somehow?
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4answers
282 views

Is there any reason for the rear frame and bottom bracket to be asymmetric?

I just received a new non-brand carbon frame and immediately noticed that the bottom bracket looks to stick out significantly more to one side than the other, and the rear bottom forks also seem to be ...
3
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2answers
90 views

Creaking pressfit bottom bracket

From the questions here and a lot of opinions elsewhere, it seems that press fit bottom brackets are bound to be creaking, almost by design, due to low tolerances and how they're installed. It seems ...
5
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2answers
169 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....
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2answers
111 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 ...
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2answers
61 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 ...
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1answer
52 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 ...
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3answers
154 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
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2answers
414 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 ...
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3answers
110 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 ...
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2answers
108 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 ...
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2answers
155 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
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1answer
71 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,...
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0answers
105 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
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2answers
76 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
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1answer
130 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 ...
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1answer
663 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 ...
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2answers
513 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,...
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1answer
98 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
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1answer
355 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
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1answer
185 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
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1answer
147 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 ...
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1answer
50 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
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2answers
474 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
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1answer
42 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
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1answer
141 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 ...
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4answers
527 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 ...
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1answer
127 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
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2answers
113 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 ...
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1answer
73 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
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1answer
195 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 ...
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2answers
150 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
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1answer
59 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
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3answers
390 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 ...
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2answers
31 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 ...
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1answer
185 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 ...
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3answers
401 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 ...
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2answers
922 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 ...
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2answers
259 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 ...
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2answers
171 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
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1answer
80 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. ...
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1answer
145 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
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1answer
448 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 ...