Harvesting bb90 compatible gxp bearings from bb86/bsa bb?

Discuss light weight issues concerning road bikes & parts.
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alcatraz
Posts: 2308
Joined: Mon Aug 29, 2016 11:19 am

by alcatraz

Hi ww's

I need to ask if someone has tried to harvest bearings out from the bb86/bsa cups?

I live where a bb90 gxp bottom bracket costs a fortune, because it's scarce. I was thinking to get only one to get the necessary spacers/dust covers but later buy the bb86/bsa bottom bracket thats easy to find and harvest the bearings.

Are the sram bb86/bsa gxp bb's with standard 37x22 + 37x24 bearings?

Thanks

by Weenie


TomHelly
Posts: 72
Joined: Sun Feb 22, 2009 12:31 pm
Location: Hobart, Australia

by TomHelly

Yep, you can do that. I've done it the past because I had a spare SRAM PF86 lying around.

Might need to give the outer race a hit with some brake cleaner and a blade to get off any residual retaining compound.

You can also reuse the red silicone driveside bearing shield, tends to drag less than the one Trek use.

:beerchug:

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ms6073
Posts: 2799
Joined: Fri Jul 23, 2004 8:24 pm
Location: Houston, Texas

by ms6073

Will echo previous poster but this assumes you have the proper tools such as an Enduro BRT-003 to extract/press in the bearings.
Michael - The Anaerobic Threshold is neither...

alexmcm09
Posts: 41
Joined: Tue Feb 13, 2018 11:02 am

by alexmcm09

alcatraz wrote:
Wed Mar 06, 2019 11:14 am
Hi ww's

I need to ask if someone has tried to harvest bearings out from the bb86/bsa cups?

I live where a bb90 gxp bottom bracket costs a fortune, because it's scarce. I was thinking to get only one to get the necessary spacers/dust covers but later buy the bb86/bsa bottom bracket thats easy to find and harvest the bearings.

Are the sram bb86/bsa gxp bb's with standard 37x22 + 37x24 bearings?

Thanks
Where do you live? I accidentally bought some GXP bearings for my Madone and never got around to returning them. You can have them for cheap - I'm London based.

alcatraz
Posts: 2308
Joined: Mon Aug 29, 2016 11:19 am

by alcatraz

China :lol:

Thanks for the offer but it's too troublesome. The bb86 bb is like 10usd and I can get one easy and quick.

Thanks for the helpful replies. You helped me a lot already. Appreciate it.
/a

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FIJIGabe
Posts: 1867
Joined: Tue Sep 11, 2012 6:07 pm
Location: The Lone Star State

by FIJIGabe

Have you looked up the model number of the bearings (2237)? A lot of eBay sellers are out of China, so I'm surprised they are that expensive there.
Madone 9 - https://bit.ly/2Nqedbn
Emonda SLR - https://bit.ly/2UK5FP8
Crockett - https://bit.ly/2Xem4sk

Madone 5, Cobia. I own a lot of Treks.

alcatraz
Posts: 2308
Joined: Mon Aug 29, 2016 11:19 am

by alcatraz

Most bearing kits here use the reducer sleeve, which I'd be ok to use if it were a training bike or recreational bike but this time it's for racing so I'd like to try the clamped NDS bearing style and supplied with original seals and combination of seals and bearings that are actually designed to fit together.

Even trek original bb's now are industrial NSK 6805 bearings with a plastic reducer sleeve. We've tried those and they work ok but we've had issues with water ingress. We want to try something else.

Francois_Viviers
Posts: 194
Joined: Sat Oct 25, 2003 7:12 pm

by Francois_Viviers

Removing bearings from a press fit cup can be difficult considering how big the retaining lip is inside of cup. This works pretty well- https://wheelsmfg.com/presses-tools/bea ... r-set.html

Then just a case of pressing in a new bearing.

bm0p700f
in the industry
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Location: Glermsford, Suffolk U.K
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by bm0p700f

Race Face make or made the ideal bearing extractor.

alcatraz
Posts: 2308
Joined: Mon Aug 29, 2016 11:19 am

by alcatraz

It was easy to get the bearings out. I used a 24mm extractor (huge looking punch with three little clips that separate and lock in place between the punch and the inner race). It worked for the 22mm id bearing as well as the 24mm id one.

I just heatgunned the cups, put a book over the punch to soften the blow and in two relatively gentle blows the bearing was out. Unharmed, which was my concern.

I used an original sram gxp bb86 bb and the outer diameter of the bearings is 37mm. The bearings are truvativ sealex which hopefully should be good. Supplied were new dust covers and the wavy washer, which is nice to swap at the same time.

I'm hoping to get rid of the pesky water ingress problem I had with previous bearings (tried both trek original bb and skf bearings). I think the problem is with the dust covers not working too great to keep the moisture away and letting some accumulate near the seal lip.

These truvativ (made by skf i hear) come with a special seal shaped with an edge that the dust cover kind of fits over to provide one more obstacle for the moisture to pass before reaching the seal lip. This is not available on older or newer trek original bb's for shimano cranks. The new one merely has the plastic insert over an NTN industrial 6805 bearing with flat seals. Works ok on some bikes but my friend's just cant survive more than a year. It's got something to do with the sweat constantly flowing past the nds bearing. I filled the cavity between insert and bearing with marine grease and still the same result.

Other trek riders in our group don't have this problem. Must be something with how he sweats and where it goes. :lol:

by Weenie


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