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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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4 votes
1 answer
315 views

"Vintage" internal cable routing to external

I have an "old" bicycle. The branding on the frame suggests it's a "Coppi", and I believe it to be from the 80s. There's a lot that I don't know about the bike, but for the ...
Dillon Chan's user avatar
1 vote
0 answers
23 views

JIS or ISO standard on Merlin Road 92 Titanium bottom bracket spindle?

My early 90s Merlin road frame got that titanium spindle and I wonder whether it is JIS or ISO square tapered. According to the catalogue the name of the bottom bracket is "Beta-C"
sjakobi's user avatar
  • 111
2 votes
2 answers
120 views

What is the difference between Shimano SM-BBR60 and Shimano BB-MT501

Are these 2 bottom brackets compatible? Is one 'better' than the other? Is one more durable than the other, more efficient than the other? I would guess that the BB-MT501 is meant for dirtier ...
John Doe's user avatar
  • 353
2 votes
2 answers
354 views

Left side crank arm stuck to spindle due to stripped threads, how to remove bottom bracket

The bicycle in question is a "Schwinn Women's Ranger 26" Mountain Bike". It has a slight play in the crank arms, stemming from the bottom bracket. I tried taking the crank arms off, and ...
hyankov's user avatar
  • 131
1 vote
1 answer
39 views

Are 68mm and 73mm bottom bracket left side cups identical?

My MTB has a 73mm bottom bracket shell but it had 68mm BB installed. I found and purchased a Shimano BB-ES300 73mm BB but unfortunately I had to break apart its plastic cup (left side) since I ...
Ender's user avatar
  • 2,032
1 vote
2 answers
103 views

FSA B3155 bottom bracket compatible replacement

I have Orbea orca m35i with Shimano cranks (24mm). During bottom bracket bearings replacement, the cup got damaged. It says "FSA B3155" on the cup, FSA support said this would be a ...
kimreik's user avatar
  • 173
1 vote
1 answer
66 views

bottom bracket axle length, chainline and crank compatibility

TLDR: How much leeway there is, if any, in selecting the bottom bracket axle length for octalink or square taper cranks in order to reduce chainline? Background: I'm doing some minor modifications to ...
stativ's user avatar
  • 113
5 votes
1 answer
103 views

FSA Mega Exo 24 threaded shell BB turns free when off the bike, but turns rough and gritty once installed

My FSA Mega Exo BB is about 2 years old and came on the bike when I bought it new. The right-side bearing is fine. However, the left-side bearing is gritty and resistant when installed in the frame, ...
Darren C.'s user avatar
  • 153
2 votes
1 answer
79 views

New Bottom Bracket grinding/crunching?

I recently bought a new Shimano BB-MT501 bottom bracket and installed it. However, once I put the Hollowtech crankset back in place, when turning the pedals there is a very obvious grinding or ...
Matt's user avatar
  • 21
6 votes
3 answers
2k views

Is it correct that the bottom bracket shell thread does not go all the way around?

On the inside of the bottom bracket shell, the thread does not go all the way around. At the places where the tubes are welded (or attached) into the bottom bracket shell, there are holes in the ...
AhseemHermanson's user avatar
4 votes
1 answer
106 views

How to replace internal BB with external BB on belt drive bike?

My Rohloff touring bike has an internal bottom bracket (BB). I would like to replace this with an external BB. Current components Front Sprocket: Gates Carbon Drive, CDX, 4 bolt 104mm BCD, 50 teeth ...
AhseemHermanson's user avatar
7 votes
2 answers
2k views

What is this bottom bracket tool called?

I came across this tool on Amazon India, to remove the bottom bracket. I don't know what this tool is called. I've seen similar tools at motor workshops, so I'm assuming it is a common tool and not ...
Mellow Monk's user avatar
4 votes
1 answer
81 views

Silverback Bottom Bracket Replacement

I have removed the bottom bracket from my bike as it was very wobbly. I am trying to teach myself about these things and I am making progress however the bottom bracket looks weird. Granted I have not ...
James Burton-Durham's user avatar
5 votes
3 answers
341 views

Bottom bracket not centered in BB shell

I removed my bottom bracket because there was creaking sound while I was pedaling. Cleaned it and wanted to reinstall but the crank in the middle was hardly turning when I fully tightened the cups on ...
Ender's user avatar
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1 vote
1 answer
110 views

Bike pedaling makes cracking noise under middle or high load

Can this be related to bottom bracket bearings of Race Face BB92, PressFit? The chain is freshly lubricated and quite a new one. No noice is produced when pedalling with low load or not pedalling. ...
petrsyn's user avatar
  • 143
1 vote
2 answers
84 views

Bottom bracket confusion

I have a 2016 Merida Big Seven 100 27,5" XC MTB which I bought from second hand market. It came with a 68mm cartridge style BB. However I found out that this bike has originally 73mm BB. What ...
Ender's user avatar
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4 votes
2 answers
403 views

Bottom bracket BSA, 68mm vs. 73mm

I have the bottom bracket shown below, that needs replacement. The bike is from 2014. I live in Argentina, and here I see plenty of 113mm x 68mm in the market. But I cannot get a 113mm x 73mm as the ...
sancho.s ReinstateMonicaCellio's user avatar
4 votes
1 answer
132 views

Bottom bracket BSA, brand question

EDIT: I have removed the part of the question about the size and moved it elsewhere, as it is the most important part as of now. I have a bottom bracket that needs replacement (or repair?). The bike ...
sancho.s ReinstateMonicaCellio's user avatar
2 votes
1 answer
58 views

Square-taper crank wobble/movement in only one spot

For square-taper aluminum cranks: When my drive-side crank is in the 12:00/highest position and the non-drive side in the 6:00/lowest position, there is slight play between both cranks (it rotates ...
Laoshi's user avatar
  • 739
2 votes
1 answer
178 views

internal routing and bottom bracket sleeve

I was wondering regarding the sleeve that comes with the bottom bracket I got from chris king. My frame has internal routing, that I believe entails that cables should go through the bottom bracket. ...
yuvalon's user avatar
  • 523
0 votes
2 answers
150 views

front chainline adjustments for 42.5 rear chainline

I have a 42.5 rear chainline (12 speed sram eagle). In the front, I purchased a eewings-mountain crank. According to the docs, the offset is (55-chainringoffset). If I get a 6mm offset chain ring, it ...
yuvalon's user avatar
  • 523
4 votes
2 answers
579 views

Guess the erased text on this bottom bracket

I'm trying to keep my old mountain-bike alive, it's been so good to me. I acquired the proper tools to remove the crank and, well I guess I have two questions: There was a lot of rust and water in ...
Morten Nørgaard's user avatar
2 votes
1 answer
50 views

Installing crank on threadfit30

I wanted to get advice regarding installation of new bottom bracket and crank. My frame BB shell is BSA68. Bottom bracket is threadfit 30 crank is eewings mountain (which expects a BSA73). I looked ...
yuvalon's user avatar
  • 523
3 votes
1 answer
143 views

Will this combination of crankset work?

My frame specification for bottom bracket is BSA 68mm. Would the following bottom bracket and crankset fit together? cane creek eeWings Mountain (link) Chris king threadfit 30 bottom bracket (link) ...
yuvalon's user avatar
  • 523
4 votes
1 answer
203 views

BB386 bottom bracket - Is this kind of bearing wear normal?

I had my carbon road bike at service and the BB bearings (again) needed replacing, according to the mechanic, the drive-side one was hardly spinning and the other one also pretty much done with. Can't ...
DoNuT's user avatar
  • 4,496
3 votes
1 answer
209 views

Bottom bracket differences

what is the benefit of a more expensive bottom bracket? I just purchased a used Cube Agree C:62 (previous version of https://www.cube.eu/.../d3c24ded01f0b52c27caca216a293153...) without a bottom ...
user2912328's user avatar
1 vote
1 answer
171 views

I have a Triban RC100 (Women's bike, small) what size bottom bracket does it have?

I recently crashed my bike and bent the stock crankset so I am thinking of buying a new one and replacing it but for that I need to know what size bottom bracket comes with a stock Triban RC 100 women'...
einstein dhayal's user avatar
4 votes
4 answers
690 views

How can I measure whether pedals and bottom bracket are properly aligned to each other and parallel?

I get a weird sensation on the left pedal when I'm riding one of my bikes, as if the pedal was not perpendicular to the crank arm. It feels like the pedal is moving under my foot, although there is no ...
Robert's user avatar
  • 2,069
1 vote
1 answer
93 views

Replacement for VP-BC73E Bottom Bracket

I cannot find my bottom bracket online anywhere. It's called "VP-BC73E ". However, I can find loads of "VP-BC73" (E is missing). Would it still fit/work? I found this information ...
James's user avatar
  • 13
0 votes
1 answer
179 views

Tiny dent near the bottom bracket of a new hardtail - should I be concerned?

I’ve just purchased a new Trek Roscoe 7 (aluminum hardtail mountain bike) recently and I’ve noticed this tiny little dent today. It is on the drive-side chainstay near the bottom bracket. Should I ...
TommyYOyoyo's user avatar
0 votes
1 answer
319 views

2018 Diamondback bottom bracket size

Does anyone know what size a 2018 Diamondback Line bottom bracket is?
Sam44's user avatar
  • 1
1 vote
1 answer
79 views

Can someone please give some advice to help find a new crankset?

I apologize in advance if I mix-up some lingo, I have almost no experience in fixing bicycle drivetrain. Previously I had Comet CKM-7159 as crankset (I managed to find this datasheet that seem to ...
kazaker's user avatar
  • 13
4 votes
1 answer
404 views

How to remove and replace wire pins from axle?

I have a Kent adult tricycle. It has a band brake attached to the rear axle. The brake pad is old and no longer grips, so I need to replace it. Apparently I can't just replace the pad because it is ...
causative's user avatar
  • 143
3 votes
1 answer
550 views

Should I use fiber grip or grease when installing a bottom bracket into a carbon frame?

I am assembling my first carbon road bike and came across a question regarding on how to install the bottom bracket. I decided to go for this Ninja BBRight for my Cervelo Caledonia. The Token's ...
Bob's user avatar
  • 292
6 votes
1 answer
645 views

Noisy bottom bracket SHIMANO BB-RS500

About a year ago I've got this Stevens Supreme fitted with Shimano Tiagra BB-RS500 bottom bracket. In less than 2 months it started clicking and screeching loudly which only had gotten worse over time....
Petr Gladkikh's user avatar
3 votes
1 answer
3k views

How can I know if I need spacers for my bottom bracket / crank?

I am assembling a bike on my own and came a cross the topic spacers for bottom bracket/crank. I am installing a Shimano FC-R7100 crank with the bottom bracket model SM-BBR60. By taking a look at the ...
Bob's user avatar
  • 292
8 votes
2 answers
219 views

Another very stuck bottom-bracket – non-standard size (37 mm flats)

my name is Alex and I’m new here. I’m a bit of an amateur but I’ve decided to attempt the modernization of an old French Liberia racer from 1978. The aim is to create a bike I can use as a daily ...
TooMuchCoffeeMan's user avatar
2 votes
2 answers
578 views

Which tool to remove this bottom bracket nut - photo provided

I have an Apollo Transfer 21 inch frame and need to remove the bottom bracket. It seems to be a screw in bottom bracket. I am new to bicycle maintenance by the way. I tried a 26mm spanner to remove ...
Angus Comber's user avatar
0 votes
1 answer
62 views

Trek crossrip ltd 2015 bottom bracket model

Hello I have a Trek Crossrip ltd 2015 gravel bike. The frame is alpha aluminium 100 series and the bottom bracket is Hollowtech II. What bottom bracket should I replace it with?
Harri Juus's user avatar
2 votes
1 answer
192 views

Shimano BB: add grease over threadlock?

The dealer manual for the Shimano BBR60 bottom bracket says to grease the threads of the cups before inserting. But I noticed that the threads have some kind of grey threadlock compound applied to ...
someguyinafloppyhat's user avatar
2 votes
1 answer
274 views

1 piece to 3 piece crank conversion

I wish to convert my 1 piece crank to a 3 piece crank. I have a conversion kit that presses into the bb shell and accepts a cartridge style bb. I went to order one and realized I have no idea what ...
Raymond Dunne's user avatar
0 votes
0 answers
56 views

Damaged carbon fibre [duplicate]

My chain dropped and got stuck in my bottom bracket while I was going uphill. I think the force from the pedal stroke damaged the carbon fibre. Wondering what is recommended when something like this ...
Jocelyn's user avatar
0 votes
0 answers
55 views

What is the correct BB spindle length for Kooka cranks?

Does anyone know the correct square taper bottom bracket spindle length for an early 90s Kooka triple mountain bike crankset?
Noah Sutherland's user avatar
3 votes
2 answers
125 views

BB snapped and stuck inside shell of euro threaded frame?

I was in the process of prepping to install a new BB on my bike when I noticed this remnant that I believe might be part of my old BB. To my novice eyes, it looks like something snapped and is now ...
Terry T's user avatar
  • 85
1 vote
1 answer
345 views

Which mid drive motors use the same frame interface?

One concern with mid drive e-bikes is that if the motor breaks in ten years, probably there is no exact replacement available. But do the manufacturers keep the same interface for their different ...
Nobody's user avatar
  • 1,779
4 votes
1 answer
217 views

Bottom bracket has play. Can I still tighten this, or do I have to replace it/fix it properly? Tools? (incl. videos and photos)

I'm staying with a relative and borrowed her bike for a ride. It now has play on the bottom bracket - as shown in videos below. TL;DR Is it possible to judge if I can still just tighten this, or do I ...
pateksan's user avatar
  • 2,364
3 votes
1 answer
90 views

Frame and bottom bracket compatibility

I have problems with adjusting front shifting on my MTB so I suspect something is wrong elsewhere. This is a 27.5" Merida Big Nine 100 XC MTB. Its chainset has been replaced with a Shimano FC-...
Ender's user avatar
  • 2,032
3 votes
0 answers
75 views

Request for clarification of bottom bracket threading

I know that bottom brackets have a left-hand thread on the right side, and a right-hand thread on the left side. But I fail to understand why. I would have thought it should be the other way round, to ...
Burki's user avatar
  • 1,545
2 votes
1 answer
98 views

BB/Cranset creaking on/off

I'm having an issue with a creaking sound on a brand new bike (see video below). It seems to happen after 30+ min rides, you can faintly hear it when the pedals are spun backwards but this usually ...
Jordan's user avatar
  • 21
6 votes
1 answer
184 views

Small metal pellets in a new frame

I am working on assembling a new boxed bike (aluminum Kona Libre), starting by tearing it completely down and making sure all components are properly installed, greased and adjusted. The headset felt ...
djwicket's user avatar

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