Author Topic: OG-Evkin CF-052 bottom bracket troubles  (Read 487 times)

TidyDinosaur

OG-Evkin CF-052 bottom bracket troubles
« on: March 17, 2023, 12:47:25 PM »
In november of last year I bought this frame. It has a BB92 bottom bracket and it was my first time installing this type of BB. I bought a Ztto screw together BB but it went in really difficult. The drive side went in ok, but the ND side went in crooked and only with some force (this is a screw together BB so the left and right side are always parallel to each other). It also did not sit flush with the frame. The back of the BB was touching the frame when in the front there was still a gap of 1-2mm. I used more force to screw it in until it looked OK-ish... I have only done 400km with this bike but the drive side BB did start to come out once so I had to screw everything together again.
Today it was once again coming out so I decided to install a normal press fit BB... To my surprise this BB had the same problem with the fitting. Drive side went in OK. Non drive side needed more force AND went in crooked the same as the other one. There is a gap of 1-2mm between BB and frame in the front and the back is tight...

So now I am thinking the problem is not me, or the BB, but there is a problem with the frame... What do you guys think? Anyone had this happen before?



carbonazza

Re: OG-Evkin CF-052 bottom bracket troubles
« Reply #1 on: March 17, 2023, 03:21:58 PM »
Did you check if the faces are parallel?
Maybe with two rulers, to check a parallax and see if they deviate too much.

There is a tool to face the frame, but I'm not sure, grinding 2mm of carbon may be a lot.
Did you measure the diameter with a calliper to see if they fall within the tolerance?

Then contact OG-Evkin, to know what they think.
They are responsive, unfortunately  to a certain point in my experience.
Hambini has some videos where he shows how to fix some poorly built BB shells.

TidyDinosaur

Re: OG-Evkin CF-052 bottom bracket troubles
« Reply #2 on: March 20, 2023, 09:52:33 AM »
Thank you for the advise! Since the new BB is now installed measuring will be difficult...
I did a 45km MTB ride on Saturday and it seems to hold up. It is noisy and creaks, but I think the alignment issues have caused the inside of the BB shell to be enlarged a little bit from the grinding of the BB in the shell. I am thinking of trying to install it with some Loctite (but the one I need seems to be crazy expensive...).

Maybe I'll try to contact the seller, but I am not expecting much from that side...

I'll see how it hold up (there is a small crack on top the the BB housing from forcing the BB in...). Worst case I'll have to get a new frame after the winter of 23-24...