Whyte MTB bottom br...
 

  You don't need to be an 'investor' to invest in Singletrack: 6 days left: 95% of target - Find out more

[Closed] Whyte MTB bottom bracket unscrewing itself

5 Posts
5 Users
0 Reactions
270 Views
Posts: 0
Free Member
Topic starter
 

I picked up a second hand Whyte 603 for the missus earlier this year. I believe it's the 2017 model. Really clean and looked to have done minimal work.

After a few days having it home I noticed some play in the cranks, and the bottom bracket had unscrewed itself. I removed it, greased everything and did it all back up fairly securely.

It's been used probably 10 times since the initial fix, only once slowly plodding around anything non-flat, and it's unwound itself again.

What should I be doing differently or inspecting when I take it apart again?


 
Posted : 29/12/2018 9:07 am
Posts: 1748
Free Member
 

What cranks and bottom bracket?

I'd clean it up with some IPA thoroughly, an then apply a bit of blue loctite / threadlock.


 
Posted : 29/12/2018 9:30 am
Posts: 3562
Full Member
 

did it all back up fairly securely

Do it up tighter - BB shell torque is normally in the region of 35-50NM (check for your specific one) which is a fair amount of leaning on it. If you do that and it still comes loose check for stripped threads..


 
Posted : 29/12/2018 9:34 am
Posts: 0
Free Member
Topic starter
 

Cheers I was unsure on loctite being acceptable there, but a few dabs may be OK I guess!

It's a square taper crankset and internal bottom bracket, fairly dated design I believe. May just be I didn't tighten them up enough but hopefully that's the case.


 
Posted : 29/12/2018 8:12 pm
Posts: 0
Free Member
 

I thought BSA threaded BB's were designed such that they didn't unscrew under normal use?? Thought it was Italian threads that were more likely to unscrew?

Is there something else amiss? Cracked shell? Sticking bearings??


 
Posted : 30/12/2018 10:43 pm
Posts: 1617
Free Member
 

could well be that the threads are damaged now if it's been ridden loose.

Might be worth fitting a new BB now to get fresh threads and hope the frame is okay.


 
Posted : 31/12/2018 12:35 am

6 DAYS LEFT
We are currently at 95% of our target!