Fitting power torque bb86 BB in carbon shell - help please

LukeHurst

Hi

I have conducted internet searches and the results I find are inconclusive so I would like to ask for opinions on recommended method to install a press fit bb in a carbon frame.

I have a Scott CR1 carbon frame with carbon BB shell and it measures 86.5x41mm so it's a BB86. My chainset is a Campagnolo Centaur Power Torque. I purchased the frame second hand so it does not have an existing BB installed.

I have read conflicting information about the best method to install the BB. Some say use grease or anti-seize or loctite 609 or dry fit.

I'm inclined to use loctite 609 but I don't want to end up with a BB stuck in the frame that I can't remove next time the bearings need replacing.

Any thoughts/suggestions?

By the way, I already have a headset press and tool for removing the cups and I've built up countless bikes myself so don't really want to go LBS if I can avoid it.

Thanks

Luke.

keef66

My CR1-SL has a factory fitted Shimano press-fit BB. Apparently fitted dry, but I won't know for sure till I have to replace it. Still smooth / silent after 2 years...

Looks like your Campag press-fit cups would stay in the BB shell more or less indefinitely and you can just replace the bearings when required? I'd suggest fitting them dry. Definitely no grease...

LukeHurst

keef66 wrote:

My CR1-SL has a factory fitted Shimano press-fit BB. Apparently fitted dry, but I won't know for sure till I have to replace it. Still smooth / silent after 2 years...

Looks like your Campag press-fit cups would stay in the BB shell more or less indefinitely and you can just replace the bearings when required? I'd suggest fitting them dry. Definitely no grease...

Thanks for replying. Yeah the Campag will be an almost permanent fitting although I have read that the non-drive side bearing is difficult to remove from the cup and you're supposed to replace the whole cup/bearing.

I guess if I fit them dry and suffer movement/creaking I could always remove and try loctite or similar afterwards.

on-yer-bike

I fiited a Sram BB86 into a BMC and the instructions said dry. When changing bearings wth Sram and Shimano you bash out the cups with bearings and change both. Removing BB86 cups takes a special tool and a lot of welly with a big hammer. Its brutal.

cycleclinic

I awlays use antiseize to fit these things. Why on removal your not want to insert the tool and give a whack on to find the bearing comes out leaving the cups behind. It is not a huge problem as a hack saw blade deals with withe the offending cup quickly but it hassle you can do without. Unfortunaly mtbs that come for the first bb change normally go this way. Grease is washed out antiseize when washed out will always leave the copper behind as a lubricant.

LukeHurst

on-yer-bike;

I've got a proper headset bearing removal tool which is a metal sprung thing that park use in their videos to remove BB cups so hopefully that'll do the job when I need to bash them out.

thecycleclinic;

Do you think regular car copper grease would work, the stuff you use on the back of brake pads? I've already got some of that and would save me buying more stuff. I'm guessing the tolerances are so tight the grease won't cause the BB cups to slip?

cycleclinic

coppaslip is what i use and the cups wont slip.

LukeHurst

Thanks for the help everyone.

I have now fitted the BB in my frame. I applied a little coppaslip as suggested and pressed it in without too much fuss. I haven't ridden the bike yet so only time will tell if I have any issues.