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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
72 views

Single chainring conversion issues

I've got a Specialized Crosstrail Elite. I want to get rid of the front derailleur and go for a single front chainring. Its a 68mm BB shell but needs a 73mm BB with spacers. It currently has a FSA ...
3
votes
1answer
51 views

Shimano Front Chainwheel FC-MC19 Replacement?

I have Shimano FC-MC19 22/32/42 175mm crankset on my MTB for 17 years and it's time to replace it but I find it difficult to figure out what new crankset will fit my bicycle. Two years ago I replaced ...
3
votes
4answers
105 views

Pitted Cups - Can I get away with this level of pitting?

I have two bottom bracket cups that I'd prefer to reuse (finding Avocet Bottom Bracket cups even on Ebay is hard!). I have purchased a replacement Avocet spindle of the correct size. I'm wondering if ...
3
votes
1answer
57 views

Octalink v2 bottom bracket on italian shell

I'm re-building an old Italian Bottecchia mountain bike which has Italian BB shell (70mm) and the previous bottom bracket was a square taper with 130mm spindle (measurement confirmed via calipers.) I ...
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3answers
91 views

Can I grease a crank spindle/bracket without disassembling the crank set?

A bit of history: the grooves on the spindle are partially destroyed/skewed by cycling with a loose crank, so I applied a lot of force to a hexdriver to get the crank arm on. Now, it would be quite ...
1
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2answers
103 views

What is this bottom bracket standard called

I am looking to buy a cheapish power meter.I Would like to see if am improving at all. I want to know my bottom bracket standard and if I can fit a bottom bracket power meter?
5
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3answers
284 views

How to install press fit bottom bracket into new frame

I bought a new carbon frame, which came with a press fit bottom bracket. All of the resources I can find for the installation of these includes information about how to remove the old bottom bracket, ...
0
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1answer
78 views

Use 105 crankset on 9x2 Sora equipped bike

Want to ditch my basic square taper FSA Vero (50/34) crankset on 9x2 speed Sora drivetrain (2018 Devinci Silverstone 2) in favor of 105 compact crankset. I will attempt to get one in 50/34 not to mess ...
3
votes
1answer
46 views

Bottom Bracket for Trek Crossrip Elite 2014?

I am planning to upgrade my group set to 11 speed 105 along with the bottom bracket. However, I have no idea what type of BB should I get and brand. If anyone could help me that would be great?
3
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2answers
59 views

Strategy for removing a bottom bracket with plastic retainers?

Bottom brackets that have plastic retainers have a reputation for being problematic to remove. Often the tool interface on the plastic retaining ring will shear off if the plastic is old or the bottom ...
5
votes
1answer
101 views

Threadlocker and Bottom Brackets

The main threadlocker brand available in the US describes its red compound as "permanent" and requiring heat (> 550°F) to free up, and its blue compound as medium strength and requiring only hand ...
3
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2answers
67 views

What crank arm bolt is required here?

The crank arm on my Decathlon Triban 520 became loose during a cycle. On inspection the crank arm bolt is missing. What bolt do I need as a replacement? (Or how can I figure it out?) The manufacturer ...
1
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3answers
75 views

how do i put my bottom bracket back together

I was bloody relived I could get the bb apart that I just rushed ahead and fogot to take note of how it came apart.DOH!! I now have the following dilemas 1)What size bearings were they again(dont ...
1
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1answer
61 views

Is ISIS compatible with BSA?

I want to get a Cyclone motor to install into my bike. My bike has a 120mm BSA bottom bracket, and the motor is available in Square Tape and ISIS varieties. Are these compatible?
2
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2answers
91 views

Is the Shimano UN55 bottom bracket in 68x122.5 and 68x127.5 sizes JIS square taper?

On one online sales site there's a drop-down widget showing various sizes of the Shimano UN55. "JIS spindle" appears as a bullet-point next to someone of the size choices but not all of them, hence ...
0
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1answer
61 views

How to remove stuck Shimano Hollow-Tech bottom bracket cups?

When I tried to remove the bottom bracket bearing cups using the BB tool it was very hard to move or it's just stuck. Tried WD40 then slowly tapping the tool using a mallet didn't work. To cut the ...
2
votes
1answer
97 views

What bottom bracket do I have

What type of bottom bracket do I have? I'm looking for a video on how to service my bottom bracket but I'm not sure what type I have. I have a Cannondale CAAD8 from 2011 with a Shimano 105 groupset. ...
3
votes
1answer
191 views

JIS and ISO square taper

I've read Sheldon Brown's page on JIS and ISO and have read exchanges in forums about the pros and cons of using ISO cranks on JIS bottom brackets. If my understanding is correct, these standards ...
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2answers
109 views

Loud “thunk” sound each time my shoes pass the 1 o'clock position with both shoes

Folks, I need a hand. Does anyone know of a bike mechanic that can diagnose problems via FaceTime or another audio/video app? I ride strictly indoors (I’m in Iraq) and there’s a knocking coming from ...
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1answer
59 views

Stripped out bottom bracket

The bottom bracket of my bike was completely stripped to the point that when you push the left side crank arm, the right crank moves and you can see the bottom bracket lock move out the frame. The ...
1
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1answer
434 views

Is it possible to convert a press fit bottom bracket to threaded?

I have a road bike with a press fit bottom bracket (I'm not quite sure which kind). The guides I have watched make it seem fairly risky to replace and requires ~$250 worth of tools to replace. I saw ...
4
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2answers
100 views

What tool do I need to remove this bottom bracket?

Would I need a three-notched tool to remove this?
3
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0answers
41 views

How to solve issue with self-unscrewing Praxis Convo BB for Shimano?

I am looking to solve the issue with Praxis Convo BB which unscrews by itself during the ride. What would be the best solution? On my second ride on a Specialized Venge Pro 2019, I noticed that my ...
1
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1answer
47 views

Threading for BB (British) for Hollowtech 2 or square taper crankset?

I have square taper crankset from Sugino (compact double 48-34). I am using their aluminium cartridge BB (I think it's 68mm). Anyway, I was wondering what is the difference, if any, regarding the ...
2
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1answer
93 views

Bottom bracket spacers

I'm installing a Sram GXP English-threaded bearing set in my 68mm bottom bracket. It is replacing a Shimano Ultegra-level HollowTech II bearing set. The crank set I'm installing is a Sram XX 42/28, ...
0
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2answers
112 views

Square taper spindle won't fit into the bottom bracket

I'm making a road bike with random components I have in my garage. Everything works ok except for the bottom bracket which is a square taper 115mm long and it is still spinning free even if I turn the ...
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0answers
79 views

Which way does this ring go on the left crank of this Shimano deore hollow tech external bottom bracket crank?

On the inside of the left crank there is a small ring. The picture shows where the ring is meant to go. The ring is smooth / flat on one side. The picture shows the flat side which seems to have been ...
4
votes
2answers
258 views

Last ditch attempt to fix creaking bottom bracket (Epoxying the BB into the frame)

I have a Canyon Ultimate CF SL which has the all to common press fit bottom bracket creak. I use 24mm Shimano Chainset and have tried the official Shimano Ultegra BB86 and 92 Bottom Brackets, a ...
2
votes
1answer
83 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 ...
3
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2answers
686 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?
6
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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.
1
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1answer
47 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.
3
votes
2answers
111 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
140 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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vote
3answers
99 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
votes
2answers
297 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?
4
votes
5answers
391 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
242 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 ...
6
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2answers
285 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
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2answers
309 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
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2answers
212 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
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1answer
67 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 ...
2
votes
3answers
1k 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
673 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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vote
3answers
224 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
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2answers
150 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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vote
2answers
238 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 ...
4
votes
1answer
96 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,...
1
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2answers
171 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
138 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 ...