I just installed a new Shimano BBR60 bottom bracket along with a new Shimano R8100 crankset, and I can't figure out why it's not spinning at all. The cranks on my old Tiagra spin very easily, with almost no friction. What could be the problem? Is there actually an issue?
Slowly spinning bottom bracket
byu/FishermanSame6971 inbikewrench
by FishermanSame6971
18 Comments
This is not an issue. Looks to be spinning freely. This will be imperceptible under load.
it’s the excess factory grease. it’ll loosen up with some use
New grease takes time and heat exposure to be broken in properly – cranks are not meant to spin for a long time on their own, those videos of it that you see are probably ceramic bearing bottom brackets. This looks fine, and as long as it’s smooth that’s the only thing that matters
Contrary to what everyone else says, I reckon it may be a bit too tight, the only way to find out is more work, so you either keep spinning it to see if it loosens orrrrrr..
too much preload or the frame is misaligned in some way. grease or new seals dont make so much friction
I installed this exact crankset twice and it’s a bit greased up at first. Don’t worry about it, it’s spinning well enough.
I mean, that’s not the worst I’ve seen. That’s ok. your bottom bracket is not forged on mount olympus.
you should see chris kings when they need to break in
It’s a shimano BB, they all spin like that.
crankset preload too tight? did you hand tighten or tool tighten the shimano star bolt
NORMAL. This is completely normal. I don’t know if I could even count working in a Bike Shop how many of these bottom brackets I put it in my life if it doesn’t spin at all that’s a problem even without preload this is how they spend so you didn’t put too much on you didn’t put too little on. This is absolutely normal.
People love to post those videos of bottom brackets spinning forever, but in a lot of cases they’re just not tight enough. As long as you put the right kind of grease in and everything is torqued the way it’s supposed to be, don’t worry about how it looks on a disassembled bike.
Yes you need to take the frame to a machine shop, re-bore the BB, bond in a new threaded or press fit BB sleeve and then install ceramic bearing that don’t last in weather to save these important 0.2 watt.
/jk
That is completely normal, most probably just the bearing seal that saves your bearings from water and the likes. Shimano BB are pretty good in taking up slack from missaligned BB threads/cups. You will be fine. Your old bike either/and has better alignment, less/worn seals or worn bearings.
Looks perfect
You could try loosening the threaded pieces slightly and see how much it frees up. If it makes a big difference, the BB faces may not be parallel.
Because stuff like this bothers me, I “repaired” an aluminum framed bike by using feeler stock to identify the area that needed material removed and carefully filed it until it got better.
These 2 piece bottom brackets just don’t spin as free as the old cartridge style no matter how perfect the alignment is.
Normal. If you STILL think it is not right:
1. Loosen the pinch bolts on the non-drive side, loosen and retighten the plastic preload screw to just where it takes any slop out, this is a light finger tightness using a thumb wheel. Retighten the pinch bolts to spec.
2. If you still feel any once-around stickiness it is possible your frame needs the BB to be faced. If you remove the BB and there is overspray where the BB sits it might be causing a slight misalignment. Your local shop is the best hope for a chasing/facing tool.
3. There is a small chance your frame is poorly made with misaligned BB threads between the left and right side. Sadly this is a warranty issue, but is tough to prove without proper tools beyond the typical home mechanic. A BB shell that threads together is an option to mitigate, but this all gets beyond my internet armchair mechanic knowledge.
New bice.
So break is a thing here. When I was in the shop
I would spin it up with a power drill to get this started.
Hambini has some strong words for you if you want to really squeeze performance out of your BB setup.
Here’s the thing: everyone thinks that an open spinning crank, going on for an endless time is the goal.
It isn’t. It’s like pressing thumbs into a saddle to see if it is comfortable.
That resistance on a crank of minimal mass will never show on a power meter as it is far below insignificant.