Movement in BB
Author
Discussion

TheBALDpuma

Original Poster:

5,940 posts

197 months

Monday 2nd June 2014
quotequote all
I have a hollowtech BB and there is a minute amount of play when I hold the cranks and wiggle. Not visable but I can feel it. It's been around 10 years since I've been in the bike scene, at which time it was either splined or square tapered BBs, which I understand how they are put together. The hollowtech ones however I don't... Does this movement mean the bearing are knacked, or do I need to just nip something up and all will be dandy?

I know it can't be diagnosed over the net, but it would be good to know if I've got a possible simple fix before I take it to a shop/

P-Jay

11,404 posts

220 months

Monday 2nd June 2014
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They're completely maintenance free, which is the positive way of saying it's fecked - well you can in theory pull them apart and try to re-grease the bearings or get them out of the cups and replace them, but frankly it's not really worth the effort at they're pretty cheap.

They're about £20, only come in one size I believe (if they come in different ones it's only limited to the size of the plastic sleeve that sits between them to stop water ingress down the seat tube.

They're dead easy to fix if you have the right tool, which are cheap too you unscrew the old one (directions on the shell itself) and screw a new one in, just take a few moments to make sure you don't cross-thread!!

Mine last about a year, Hope make ones that are tougher but cost a lot more, Superstar make cheaper ones, but they don't last as long.

donfisher

793 posts

195 months

Monday 2nd June 2014
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P-Jay said:
They're about £20, only come in one size I believe (if they come in different ones it's only limited to the size of the plastic sleeve that sits between them to stop water ingress down the seat tube.
Two types; Italian and English.

AFAIK the plastic bit in the middle is one size but there might be spacers on the outside already that you need to keep if the BB shell is narrower than the BB if that makes sense.

TheBALDpuma

Original Poster:

5,940 posts

197 months

Monday 2nd June 2014
quotequote all
And the cranks are just pinch bolts yes?

Tbh I'm going to get my hands on a strong one as I've probably only amounted 20-30 hours of riding on this one, although I don't know how new it was when I got it, but I tend to ride fairly heavy and do a fair amount of jumps/drops.


P-Jay

11,404 posts

220 months

Monday 2nd June 2014
quotequote all
TheBALDpuma said:
And the cranks are just pinch bolts yes?

Tbh I'm going to get my hands on a strong one as I've probably only amounted 20-30 hours of riding on this one, although I don't know how new it was when I got it, but I tend to ride fairly heavy and do a fair amount of jumps/drops.
30 hours is a bit short, although it's a 'piece of string' type measurement.

Cranks require a small tool to insert into the end-cap to pull all the bearings into place, then you flip down a little bit of plastic that lives between the bolts (this lets you know it's been pulled into position) and then the pinch bolts secure it in place - the "little tool" is usualy supplied with the HT2 spanner and sometimes even incorporated into it.


Here's a vid how to do it.

https://www.youtube.com/watch?v=txxGOmbvZ30

It made me feel a bit queasy because the lad filmed it with a helmet cam, but it shows the basics. It's filmed 'real time' and last 5:25, which gives you an idea how hard it is wink

P-Jay

11,404 posts

220 months

Monday 2nd June 2014
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For reference mine last about a year on average, which is 250 hours and a week in the Alps based on fag packet maths.

upsidedownmark

2,120 posts

164 months

Monday 2nd June 2014
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Depends if the movement is radial or axial.

If it's axial, then you may just need to undo the pinch bolts, tighten the plastic cap a bit and re-tighten the pinch bolts. If it's radial it's probably knackered, or you're being too sensitive - there's always going to be some (tiny) amount of play.

TheBALDpuma

Original Poster:

5,940 posts

197 months

Monday 2nd June 2014
quotequote all
upsidedownmark said:
Depends if the movement is radial or axial.

If it's axial, then you may just need to undo the pinch bolts, tighten the plastic cap a bit and re-tighten the pinch bolts. If it's radial it's probably knackered, or you're being too sensitive - there's always going to be some (tiny) amount of play.
Erm, it's up and down hehe

There didn't use to be play and no there is, so assuming it's a bit tired.

upsidedownmark

2,120 posts

164 months

Monday 2nd June 2014
quotequote all
biggrin

Axial - along the axle, i.e. left to right. Radial - across that. So yeah, up and down (or forward and back wink )

Sounds like something isn't right, no detectable play in mine after 10,000km - though I think I'm doing rather well at that!