HI HOPE MAKES A SHIM SO YOU CAN USE A GXP ON SHIMANO BB YOU CAN ORDER FROM CHAINREACTIONCYCLES. IT WORKS WITH THE SM 91 ADAPTOR THAT IS IN THE FRAME. EASIEST SOLUTION. I WAS NOT SATISFIED (BUT THEN I AM FULL OF SH****t) HERE IS MY SOLUTION YOU WILL NEED 2 X 6509 BEARINGS 2 X SPRINGWASHERS 2 X SHIMANO TOP HAT DUST SEALS 1 X HOPE SHIM ( BECAUSE TRUVATIV SPINDLE IS TAPERED) 1 X 8MM SPACER PROCEDURE REMOVE THE SM 91 CUPS FROM THE FRAME INSERT THE SPRINGWASHERS IN THE GROOVES INSIDE THE BB SHELL PUSH THE BEARINGS INTO THE SHELL UNTILL THEY MAKE CONTACT WITH THE WASHERS INSERT THE SHIMANO DUST SEALS IN THE OPENINGS IN THE BEARINGS PUT THE 8MM SPACER ON THE DRIVE SIDE PUT THE HOPE SHIM IN THE OPENING ON THE NON-DRIVE SIDE TIGHTEN UP THE CRANK AND YOU'RE DONE THE BEARINGS YOU CAN GET FROM ANY BEARING SHOP EVEN CERAMIC IF YOU WANT. THEY HAVE THE SAME OUTSIDE DIAMETER AS BB30 BEARING (42MM) SAME INSIDE DIAMETER AS SHIMANO STD BEARING (25MM). THAT IS WHY YOU NEED THE DUST SEALS, THEY REDUCE THE OPENINGS TO 24MM. PULL THEM OFF ANY SHIMANO BB IF YOU CAN NOT FIND THEM NEW LOCALLY. THE HOPE SHIM YOU NEED BECAUSE OF THE TAPERED SPINDLE THAT TRUVATIV USE. THESE BEARING ARE WIDER, BUT THEY STILL FIT FLUSH WITH THE BB SHELL, NEEDLESS TO SAY THEY WILL BE MUCH STRONGER AND LAST MUCH LONGER THAN SMALLER ONES, AND MUCH SMOOTHER. GOOD LUCK
