Just treated myself to a new second hand bike and just trying to give it some love before I get out on it, should this splined shaft just pop out? Like it does in all the Youtube videos 😅 tapping it gently but it doesn’t want to budge! Any help appreciated, cheers!
by jonnyboy231
6 Comments
The bearing are almost certainly sealed so you won’t be re-greasing them. Why are you doing this?
No. There is a special tool to unscrew the BB. Don’t hit it with a hammer. See those internal teeth on the ring just inside the frame. Should be something similar on the back side. You need a tool that locks into those and then they just screw out. One is the bottom bracket and housing the other is just a cup as I recall. Been forever since I’ve dealt with a splined BB.
Looks like a sealed bottom bracket. Do not regrease.
If you had the correct tools you could remove the whole thing as a unit (and not regrease it). But the spline does not slide out.
Best course of action: clean up the outside, intall cranks, ride bike.
This looks like a Truvativ Powerspline axle. There are two big cartridge bearings but they are held in place by the cups. You can remove the cups with Shimano TL-UN74 or similar, pop the seals and lubricate the bearings. I personally wouldn’t bother, Powerspline cranks have a habit of falling off and quickly wearing BBs. Shimano Hollowtech II is a much better BB/crank system
If it’s a sealed bottom bracket, typically the entire unit is replaced once it becomes worn. That looks like isis which unfortunetly is not one of the cheaper standards and will cost like $50 + specialty tool to replace. I’d just clean up the outside and give it a go. if it’s crunchy, replace it.
I’m not sure exactly what kind of bb im looking at just by the picture but i suggest not wacking it again until someone else chimes in.
Maybe clean the bike first no?