converted a cheap bike from ss to fixed and the bb spindle is alr bent after 60 days with bearings kinda messed up, trying to follow guides here and there but i can just swap types right?
this is like a 3 dollar bb that came with the bike and was the only part i didnt change so far, i dont want to do hollowtech as from what i understand id need a new crankset
also what couldve caused this? a spindle shouldnt be that easy to bend, is it due to low quality? would a shimano bb fix my problems?
by butv
12 Comments
choyna steel
Infinite watts.
But yeah, just buy a decent cartridge BB from a reputable manufacturer and ride on.
It sure is. You can just swap a modern cartridge square taper in that has the same spindle length within a ~1mm difference.
Whoa! I’ve never seen that happen.
Take it with you to the bike shop so they can get the measurements for the replacement, either just the spindle or the whole BB.
Looks like really bad steel. Normally they should be rigid enough to endure a cyclist standing on pedals or even dynamic loads during somewhat aggressive ride
I think replacing it with Shimano or something close should work. No need for hollowtech
yes. new shimano BB – cheap is fine.
calm down thunder thighs
https://preview.redd.it/4zc4ptcgnazf1.png?width=626&format=png&auto=webp&s=d24e4043363d6aee9ed692360a0995d3a0467276
lol what may have happened is that something hit the crank arm really hard, another square taper bb is pretty cheap these days so you can just replace.
Whatever Shimano sealed cartridge will fit in there will be fine.
What caused it?!
Clearly, your Massive Quads – and the tremendous power they generate – overwhelmed this highly engineered part.
Please keep in mind:
With great power comes great responsibility.
That looks to be an older cup and balls spindle, you can upgrade to a modern cartridge BB with sealed bearings. Just measure the frame at the BB (68mm or 73mm) and the length of your spindle (e.g. 127.5mm is a common length) and purchase one. I just upgraded from a cup and balls to a Neco BB, and it appears to be a quality unit. Time will tell if it lasts, but it is smooth now. Be aware a cartridge BB does not use a locknut like the older loose ball BB, they just screw in until tight on both sides.
That is impressive. The bearing surfaces are certainly worn enough that you’d need to replace that anyway, but I have never seen one of these shafts deformed like that. This is solid steel with a hole drilled in it. I would check your bottom bracket shell for cracks or damage. I don’t think a human pedaling could cause this.
Yes, in my experience those are extremely low quality.
At some point I rode trials using cheap Shimano square tapered BB, it was completely fine despite extreme abuse.