TLDNR: Is Trek BB90 bottom bracket serviceable? What is involved in servicing? And what tools are needed to service it?
Details:
I just bought an used Trek bike. It is from 2020, so 5-years old.
BB is spec'ed to be BB90. Crank is Shimano 105.
I don't know the mileage on it. It looks like it is well used, so I would estimate many thousands of miles. Not sure if BB has been serviced.
I am learning to DIY. I'm new, so just learning whenever service is needed. I have never serviced bottom bracket. And there are so many different types. So bare with me on my beginner questions:
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When do I know that I need to service the bottom bracket? Should I service it proactively? Or just ride until problem arises?
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I read some some bottom bracket are sealed, so they are not serviceable. BB90 is like press fit, and I believe it is serviceable. If I service it, should I replace the bearings? Such as buying a new kit? https://www.trekbikes.com/us/en_US/equipment/cycling-components/bike-bottom-brackets/trek-integrated-shimano-bb90/bb95-steel-bottom-bracket-kit/p/26057/
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What tools do I need to remove the Shimano 105 crankset? In many videos, I I see people using crankset puller tools. But when I see video on Shimano 105, seems like only hex wrench is needed to remove the crankset.
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What tool is needed to remove and install the BB90 bottom bracket? It seems a special tool is needed. If I buy this BB tool, are they interchangeable with other bottom bracket types? My other bike has SRAM DUB Wide, T47 threaded, internal bearing. Just want to plan ahead and buy the right tool. Do I buy universal bottom bracket tool (if they exist)? Or have to buy different tools for different bottom bracket?
by D00M98
1 Comment
1: The only way to know for sure is pulling the crankset out and feeling the bearings by hand.
2: BB90 isn’t really “serviceable”. You just replace it when it wears out. You can get more life out of it by pulling the seals off of the bearings, flushing with solvent, then adding grease.
3: You’ll need a 5mm allen and the little Shimano crank tool. You can 3d print one. Shimano cranks are similar to threadless headsets, the plastic bolt sets the preload, then the pinch bolts on the NDS hold the whole thing together.
4: You need a [specific tool](https://uniorusa.com/products/tool-for-removing-bottom-bracket-bb90) to remove this BB. You’ll also need a press and drifts to install the new one. The tool you need for this is very different than the one for your other bike, because this one is pressfit and the other is threaded.