Bottom bracket upgrade question: PRESS-FIT system size 86.5 X 41
 

I have a Basso carbon frame that needs a crankset upgrade. The original crankset is a Miche "EVO Max" with 24mm bearings on both sides. Basso said that the frame is compatible with BB 72 SHIMANO or any other brand with PRESS-FIT system size 86.5 X 41 - axle diameter 24mm.

Would I need to extract the original cups out of the frame and install a new BB? Since Shimano also uses 24mm bearings on both sides, would any Hollowtech II crankset work, or would it need to be specific for Pressfit?

Thanks in advance!

Isn't Shimano using a 24mm tube spindle.. covet high end ? Dura Ace..


no guarantees..

All of shimano"s cranks have a 24 mm axle. They usually have a 25mm bearing with an insert for the final fit.

You can use whatever Shimano HT2 crank in that BB.

I tried to install a Shimano Hollowtech II double crank. If I tighten until there is no lateral play, than the crank arms rub the edge of the press-fit BB shell. Would a spacer of some kind between the bearings and the crank arms work? Maybe something like the spacer that comes with Shimano Hollowtech II triple crank, though that might be too thick. Any ideas?

Can you post a picture ? Is it rubbing the bb or the frame ?

Have you seated the spindle all the way through ? did you tap in it with a mallet ?

Shimano HT road cranks are not meant to have spacers. I've read success stories of using 0.5mm shims on occasion. But you need to be extra careful adding more spacers because the more you add the less spline surface there is for the left crank arm to grab onto. And could lead to the arm coming loose and damaging the splines. Adding more than 1mm spacers i would not recommend.

could you modify the bb cups ? i think that solution while not ideal is better than a crank arm falling off.

“Evo Max integrated bottom bracket with sealed bearingsFor use with spindles of 24mm diameter & Shimano Compatible“

Looks like Evo Max and Shimano should be interchangeable. Could you post a video on youtube?

Would a thinner spacer or dust seal like this help:


Wheels Manufacturing 24mm BB Spacer Pack

https://www.amazon.com/Wheels-Manufa...2Aentries%2A=0

https://images-na.ssl-images-amazon....AC_SL1000_.jpg

I figured it out! I needed a wave washer on the non drive side between the Evo Max BB cup and the bearing. That pushed the bearing out so that it was the correct width. No spacer was needed.