Oversize bearings in out of spec Trek Carbon Shell BB

Discuss light weight issues concerning road bikes & parts.
Mr.Gib
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by Mr.Gib

nickf wrote:Are you the original owner of the frame? Trek offers a slightly oversized bearing for this problem. I think they have a green seal on them. Or send it into trek so they can rebuild the BB area. We have never been instructed by trek to use any kind of locktite at the shop.


Didn't know Trek was in the business of rebuilding BB's.

The oversize bearings sound like the proper solution.

It's maddening to hear my Trek dealer talk about using loctite for this application when others have never been advised to use it. I guess this is what you get when and industry comes up with a sophisticated but half-baked engineering solution, and then leaves it to a bunch of poorly supported bike shop staff to execute solutions to the industry's problems..
wheelsONfire wrote: When we ride disc brakes the whole deal of braking is just like a leaving a fart. It happens and then it's over. Nothing planned and nothing to get nervous for.

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Calnago
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by Calnago

It's certainly not the most ideal application, largely because in BB90, upon removal you only really have access to the inner race of the bearing to use the tool on. Versus being able to firmly plant the tool on the outer race then give it a good "pop" and voila, it's removed. In this scenario there's a chance you could drive out the inner race while leaving the outer race intact. It's never happened to me but I could see it as a possibility. Good luck. Still before you start jamming oversized bearings in there, I think just installing some regular bearings and making sure it's all locked up correctly just to see if that works is a good idea. It's what I'd do even if I was pretty "sure" the problem lies elsewhere. Stuffing in oversized bearings is just going to make creating an even larger bore all the more inevitable I think. Good luck. Let us know how it all ends up.
Colnago C64 - The Naked Build; Colnago C60 - PR99; Trek Koppenberg - Where Emonda and Domane Meet;
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Mr.Gib
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by Mr.Gib

Calnago wrote:It's certainly not the most ideal application, largely because in BB90, upon removal you only really have access to the inner race of the bearing to use the tool on. Versus being able to firmly plant the tool on the outer race then give it a good "pop" and voila, it's removed. In this scenario there's a chance you could drive out the inner race while leaving the outer race intact. It's never happened to me but I could see it as a possibility. Good luck. Still before you start jamming oversized bearings in there, I think just installing some regular bearings and making sure it's all locked up correctly just to see if that works is a good idea. It's what I'd do even if I was pretty "sure" the problem lies elsewhere. Stuffing in oversized bearings is just going to make creating an even larger bore all the more inevitable I think. Good luck. Let us know how it all ends up.


Yes all of these issues trouble me, which is why I am appealing to the collective wisdom of WW's.

Interestingly Trek changed the design of their Sram BB recently. A new supplier and a higher quality bearing. But the drive side now includes an inner plastic sleeve/dust cover combo. I didn't like it the minute I saw it. It was with this new BB that I first noticed the problem. I re-installed the older version and there is less play. Still not right but a little better.

Another approach would be to simply obtain a supply of the older BB bearings and just run those and hope that the problem doesn't get much worse. If it gets really bad, then maybe move to the oversize bearings.
wheelsONfire wrote: When we ride disc brakes the whole deal of braking is just like a leaving a fart. It happens and then it's over. Nothing planned and nothing to get nervous for.

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nickf
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by nickf

Mr.Gib wrote:
nickf wrote:Are you the original owner of the frame? Trek offers a slightly oversized bearing for this problem. I think they have a green seal on them. Or send it into trek so they can rebuild the BB area. We have never been instructed by trek to use any kind of locktite at the shop.


Didn't know Trek was in the business of rebuilding BB's.

The oversize bearings sound like the proper solution.

It's maddening to hear my Trek dealer talk about using loctite for this application when others have never been advised to use it. I guess this is what you get when and industry comes up with a sophisticated but half-baked engineering solution, and then leaves it to a bunch of poorly supported bike shop staff to execute solutions to the industry's problems..


Have sent back quite a few frames for the BB to get rebuilt. Can you pull the bearing out of your frame without tools?

androidavies
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Joined: Sun Sep 29, 2013 4:34 pm

by androidavies

As I remember, the Trek supplied oversize bearings were 0.1mm larger outer diameter. They have deleted them in the UK, I tried to obtain them to try and solve a similar problem.
Trek warranty dept. offered to try and "build up" the bearing seats again, I sent the frame to them but they decided it was too far gone for them to attempt. Fair enough…
I solved the problem by getting a friendly local machinist to make up a "top hat" cup/shim. I put the bearing into the top hat, then pressed the unit into the oversize BB seat. It's held for the last 14 months.
The times I've come across this have been when the original bearing has seized or disintegrated, and the owner has carried on riding the bike for quite some time….

Please don't think I'm making an accusation!

Mr.Gib
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by Mr.Gib

nickf wrote:Can you pull the bearing out of your frame without tools?


Yes.
wheelsONfire wrote: When we ride disc brakes the whole deal of braking is just like a leaving a fart. It happens and then it's over. Nothing planned and nothing to get nervous for.

gtinut
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by gtinut

is there a need to use hammer to remove bearing installed with 609 or screw type puller will be enough?

hambini
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by hambini

0.1mm is like a lightyear in bearing terms. I can't believe anyone would do such a non standard size.

I'm with everyone else, retaining compound alone won't hold it in a carbon frame. You need activator. In some markets Loctite 609 is threadlock, which will not do the job at all. The activator usually comes in a white plastic bottle with a green label.

Hambini

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Calnago
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by Calnago

@gtinut:
A sharp impact is better imo than a progressive puller, simply because the bond created with the retaining compound needs to first be broken. A puller will gradually pull and pull at the bond which could potentially pull material with it versus just one sharp blow to break it free quickly. Once that bond is broken then a puller would be fine, but the impact of breaking the bond (with a proper removal tool), is usually enough to send the bearing completely out of the shell in the same blow that the bond is broken. You may get varying opinions on this, but this makes sense to me and it is how I do it, after discussing with Calfee how they do it when they need to remove these things.
Colnago C64 - The Naked Build; Colnago C60 - PR99; Trek Koppenberg - Where Emonda and Domane Meet;
Unlinked Builds (searchable): Colnago C59 - 5 Years Later; Trek Emonda SL Campagnolo SR; Special Colnago EPQ

androidavies
Posts: 74
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by androidavies

The oversize bearings that I used a couple of times came in Enduro boxes. I'm guessing that Trek talked them in to somehow making a batch, and now they're all used up….

A light year in bearing terms! That has a nice ring to it…..

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nickf
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by nickf

BB Trek BB90 Bearing Shimano Oversized 37.1 x 25 x 7 part number 527823 (If using sram add a W326785 to the order, step down spacer for the NDS)

These are really a last resort. The bearings in the frame can be removed by hand, even on a new frame. But once it get to loose to the point where they go in with little effort then its time to go for the oversized bearing.

androidavies
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by androidavies

A new part number, great! Thanks for posting this info…...

Mr.Gib
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by Mr.Gib

nickf wrote:BB Trek BB90 Bearing Shimano Oversized 37.1 x 25 x 7 part number 527823 (If using sram add a W326785 to the order, step down spacer for the NDS)

These are really a last resort. The bearings in the frame can be removed by hand, even on a new frame. But once it get to loose to the point where they go in with little effort then its time to go for the oversized bearing.

Thanks. This is what WW's is all about. More knowledge here than anywhere else. :thumbup:
wheelsONfire wrote: When we ride disc brakes the whole deal of braking is just like a leaving a fart. It happens and then it's over. Nothing planned and nothing to get nervous for.

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wheelbuilder
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by wheelbuilder

Don't use loctite or any other retaining compound on the cups of your frame or the races of the bearings themselves. Whatever Trek shop gave you this advice is mistaken. I work at a Trek shop and this happens from time to time. You need the "version 2" bearing or bearings. The have green seals like the other poster mentioned, not the blue seals found on originals. Also........if you are able to place those bearings into the cups by hand, you CERTAINLY need the version 2's. Those bearings require a press to seat fully. If the version 2 bearings are still able to be inserted without a press your carbon cups are out of spec and the frame will need to be sent back to Trek so they can re-do the cups. If you are the original owner this is done free of charge.


Edit* didn't realize the proper info was already provided above. Thought thread was only one page long! Sorry.

bikemaniack
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Joined: Thu Jul 16, 2009 9:33 pm

by bikemaniack

I see no sense to installinb BB bearings on Loctite. ust a little bit of grease and thats all. Why??...Did any bike company doing this? Did you ever seen BB mounted on Loctite in stock bike? Simple

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