[rasmuswh]

Hi guys
I'm trying to change my BB92 press fit BB's, but the cups are completely stuck in the (carbon)frame, despite being changed last year (professionaly though). I'm using the correct tools (https://www.bike-discount.de/en/buy...-tool-set-for-press-fit-bottom-bracket-780818), but no matter how desperately hard I hammer the removal tool, the cups do not move even the slightest :madman:

Any pro tips or suggestions?

Kind Regards

 

[127.0.0.1]

well....when things corrode or otherwise gumbo up, and stick to carbon, they stick hard...


hand held hacksaw blade, careful cutting, and prying and pulling with needle-nose vice grips and thin spudger (plastic flat blade) and peel that thing out in little bits. with care! you do not want to nick the bike BB with the blade.

 

[rasmuswh]

Thanks, that's a good suggestion. I think it's the way to go now. Getting no where with the removal tool.

 

[Lone Rager]

Before doing anything crazy, try backing up the frame with something really heavy and slightly padded held against the opposite side of the BB. I had a steel rod about 1.5x 8" that I would pad with a few layers of rag and have my buddy hold it end-on firmly against the frame right next to the BB. I've done many stuck press fit BBs this way. Without that mass, the frame just moves.

 

[Haggis]

Ah, pressfit BB.... the gift that keeps on giving

 

[rasmuswh]

Thanks guys!

 

[wschruba]

Before doing anything crazy, try backing up the frame with something really heavy and slightly padded held against the opposite side of the BB. I had a steel rod about 1.5x 8" that I would pad with a few layers of rag and have my buddy hold it end-on firmly against the frame right next to the BB. I've done many stuck press fit BBs this way. Without that mass, the frame just moves.

This is good advice, if a bit overkill. Grab a buddy, and have them brace the opposite side of the frame, hip on the downtube, hands on the stays. A few solid whacks should do it (and just to be clear, no tap-tap-taps; end of the handle, like you are trying to knock it clean out in one hit). If you have the luxury of an air chisel, you can use that with the proper drift/on the end of your removal tool.

By the way, the Shimano pattern tool (less-expensive-just-as-good available from Bikehand) is much more secure/distributes the force more evenly into the bottom bracket.

If it actually is stuck, you'll break the bearing out of the plastic cups, and need a larger drift to finish removing it.

 

[Lone Rager]

^^^ in my experience, you want to have a sharp impact, not a heavy one, in order to get it to break free, which is why I recommend a heavy backup weight with little padding. Holding it by hand or otherwise will still allow the frame to move enough to lessen the sharpness of the blow. I have tried it many ways many times and the weight method has been most reliable for me even with BBs that were installed with retaining compound. A buddy's hip might qualify, depending on your buddy.