Any BB90 horror sto...
 

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[Closed] Any BB90 horror stories?

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I'm seriously considering a Trek Checkpoint SL 5. Ticks a lot of boxes. But unlike some of Trek's most recent frame designs it uses BB90 not the revised T47 you'll find on the new Emonda.

Now, Trek have been making carbon frames with BB90 for ages. Anyone got a recent one that's suffered from the problems of earlier models????


 
Posted : 24/06/2020 9:22 am
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They all suffer the same issues.
My Domane now has the modified frame, where they have fitted a carbon insert into the BB so hopefully that will end my issue.

For peace of mind though, all Trek frames have a lifetime warranty so any issue with BB90 gets sorted out.


 
Posted : 24/06/2020 9:50 am
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Thanks @brads that's reassuring.


 
Posted : 24/06/2020 11:11 am
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I have a couple of Trek road bikes and they are fine
Occasionally creak
Not massively heavy use - each bike will do 1000-2500 k per year


 
Posted : 24/06/2020 11:48 am
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Nothing wrong with Press Fit as a concept, but plenty wrong with manufacturing tolerances. They are more prone to poor manufacturing, particularly on carbon frames where there isn't the opportunity to machine the BB as the last step in the manufacturing process. With a metal frame it can be machined post welding for perfect alignment and bore size. With carbon, all of that is set during the layup and curing process with little scope for post cure correction.

The answer in most cases is a Wheels Manufacturing screw together BB. Fixes 99% of creaking 99% of the time. I can't speak highly enough of them. Great quality Enduro bearings. If not there's always Hambini. I don't have personal experience, but despite his YouTube persona (which is quite amusing!), he does know his stuff.

Press Fit wouldn't put me off a frame.


 
Posted : 24/06/2020 3:43 pm
 mboy
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Press Fit wouldn’t put me off a frame.

I agree, however... in the context of Trek’s BB90, which is very different to other Press Fit standards as it’s just two MR2437 bearings that sit directly in moulded recesses inside the carbon frame, it is a system very open to issues with both manufacturing tolerances and also wear from use... When the “fix” was to press in a 0.1mm oversized bearing they had specially made, it raised industry and customer suspicions somewhat as to why Trek was so adamant about BB90 in the first place.

It’s a big part about why I’d never buy a Trek, their commitment to standards with built in obsolescence and proprietary parts...


 
Posted : 24/06/2020 3:50 pm
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Is this still the case on alloy frames too or just carbon?


 
Posted : 24/06/2020 6:59 pm
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I've just bought a 'Shimano BB-MT500-PA Press Fit Bottom Bracket - PF41-89.5/92-24' bottom bracket for my new Trek Crockett frameset (it's new despite being a 2019 model), will it fit?


 
Posted : 24/06/2020 7:18 pm
 mboy
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I’ve just bought a ‘Shimano BB-MT500-PA Press Fit Bottom Bracket – PF41-89.5/92-24’ bottom bracket for my new Trek Crockett frameset (it’s new despite being a 2019 model), will it fit?

No.

From the spec sheets, it's a Shimano BB86 standard on that frame... Same unit, but narrower...


 
Posted : 24/06/2020 7:37 pm
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Cheers mboy.


 
Posted : 24/06/2020 8:24 pm
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No.

From the spec sheets, it’s a Shimano BB86 standard on that frame… Same unit, but narrower…

BB86.5 according to Trek

https://www.trekbikes.com/gb/en_GB/bikes/road-bikes/cyclocross-bikes/crockett/crockett-disc-frameset/p/23136/blockquote >Frame300 Series Alpha Aluminium, tapered head tube, BB86.5, flat mount disc brakes, 12mm thru-axle, Stranglehold dropouts, internal cable routing, 3S chain keeper


 
Posted : 24/06/2020 8:37 pm
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I'll have to see if the bottom bracket I've bought will fit then. It was only £15 (which seems very cheap) so if it doesn't fit it won't be the end of the world.


 
Posted : 24/06/2020 8:40 pm
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You've bought a mtb bb but you need a road one. I guess you could just leave out the centre sleeve though,


 
Posted : 24/06/2020 8:43 pm
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I'll get a road version and when it wears out I'll use the mountain bike bearings but recycle the sleeve off the worn one 😉


 
Posted : 24/06/2020 9:48 pm

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