Forum menu
Square taper BB NDS...
 

[Closed] Square taper BB NDS cup depth

Posts: 407
Free Member
Topic starter
 
[#10946002]

Fitting a UN55 BB, after torquing the DS, the NDS cup doesn't sit flush with the frame but nearly 5mm below which looks odd, should I worry?


 
Posted : 04/12/2019 6:22 pm
Posts: 0
Free Member
 

Have you mistakenly  fitted a 68mm BB to a 73mm frame / shell ?

I wouldnt expect internal threads to be visible to that extent


 
Posted : 04/12/2019 6:43 pm
Posts: 407
Free Member
Topic starter
 

No, they're both 73mm. That was my first thought too.


 
Posted : 04/12/2019 6:51 pm
Posts: 13005
Free Member
 

Have you checked the actuall BB code to check it is a 73mm bb rather than the box it came in?


 
Posted : 04/12/2019 7:19 pm
Posts: 407
Free Member
Topic starter
 

I'm pretty sure I glanced at it, I might take it out to make sure...


 
Posted : 04/12/2019 7:38 pm
 kcal
Posts: 5450
Full Member
 

I have had the NDS (plastic) cup not sit 100% flush, but only by about one thread or so.

It's not a bit of swarf trapped in the threads inside?


 
Posted : 04/12/2019 7:44 pm
Posts: 407
Free Member
Topic starter
 

No, it's not sticking out, it's going too far into the shell.


 
Posted : 04/12/2019 7:49 pm
 kcal
Posts: 5450
Full Member
 

oh - misread the description - sorry!


 
Posted : 04/12/2019 7:53 pm
Posts: 407
Free Member
Topic starter
 

For anyone interested, I removed the BB and it was labeled a 73mm, with the floating cup up against the shoulder of the cartridge it measures 68mm. Luckily my LBS allowed me to return it, £30 was more than I had budgeted for.


 
Posted : 06/12/2019 8:43 am