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.)
380
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1answer
21 views
Front derailleur will not sit properly on large cog without chain rub
I bought a Vilano Commuter bike ( 3x7 speed ) a while back and recently upgraded the front derailleur, crankset, brifters, pedals and rear derailleur to tourney A070 components. However, I can't seem ...
2
votes
1answer
62 views
What is this crank and BB on this bike? And how do I take that sort of crank off?
I have a 2009 Cannondale Six Carbon 3, which supposedly has a BB30 bottom bracket and a FSA Gossamer non-BB30 crank set. It looks like this:
I'm having some creaks when I pedal and I'm trying to ...
2
votes
1answer
79 views
1991 (I think) Trek 850 MTB bottom bracket replacement. Maybe similar to 830?
I have a Trek 850 MTB that needs the bottom bracket replaced. Is there a standard size to order? If I take off the bike will there be a number that will help me order a new one or do I measure somehow?...
2
votes
1answer
78 views
Shimano LP25 Sealed Cartridge Bottom Bracket
I recently attempted to rebuild a sealed cartridge Shimano LP25 bottom bracket. These are meant to be replaced when worn out, but I thought: if someone on YouTube can do it, I can too. The problem is ...
2
votes
2answers
88 views
Not able to get crank bolt into bottom bracket spindle
I recently posted a question about changing my chainset, I was advised on this SRAM chainset which I could use which would fit my square tapered bottom bracket.
I have attempted to fit the new ...
2
votes
3answers
117 views
How to remove hex crank bolt
I have been looking online for tutorials on replacing a chainring (or three) for my Scott mountain bike: https://www.thebikelist.co.uk/scott/aspect-40-2012
When trying to take off the chainset so ...
3
votes
3answers
164 views
How do I remove this style of bottom bracket?
I am attempting to remove and replace the bottom bracket from a cheapish 1970s American department store road bike. I've gotten the lockring off, and now the non-drive side looks like this:
I ...
2
votes
3answers
103 views
Bottom bracket sizing
I have a square taper BB which has started squeaking.
When I took it out to see what size I have, when I was putting it back in I noticed that when I tighten it to a level which to me felt reasonable,...
3
votes
2answers
108 views
Worn out square taper bottom bracket spindle?
I got an used bike with a worn out left crank arm. I tried replacing with a new square taper crank arm and torqued it to 40nm; however, it started creaking soon after and the bolt had become loose (I ...
2
votes
1answer
78 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 ...
4
votes
1answer
117 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
132 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
61 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 ...
1
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3answers
220 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 ...
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vote
2answers
106 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?
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votes
3answers
415 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
92 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
67 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
votes
2answers
65 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
115 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
votes
2answers
118 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 ...
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3answers
79 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 ...
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1answer
70 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?
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2answers
163 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 ...
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1answer
92 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
105 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
295 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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votes
2answers
114 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
67 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 ...
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1answer
1k 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
votes
2answers
122 views
What tool do I need to remove this bottom bracket?
Would I need a three-notched tool to remove this?
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0answers
56 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 ...
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1answer
62 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
votes
1answer
126 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
votes
2answers
139 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 ...
0
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0answers
87 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
429 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
85 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
votes
2answers
1k 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.
1
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1answer
57 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
130 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
votes
2answers
191 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
114 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
432 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
432 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
votes
2answers
339 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
348 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
420 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
320 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 ...
