I read in Honda Tuning - May 2007 (page 97 - Larry Widmer of ENDYN) that 95mm cranks cause higher cylinder and (crank) bearing wear - why is this? What the theory why the crank bearing will wear out faster?

 

I'd say cylinder wear would be due to side loading and or piston walk. I dont know why the main bearings would wear but I'd expect the rod bearings to take a real beating at high rpm.

 

well lets think about how a connecting rod throws it weight around the crank...a larger stroke creates a larger diameter of rod swing, therefore causing more side load on anything related to that assembly(piston skirts, conn. rods, bearings, crank, and even block bore distortion) there is a reason why larger stroked hondas dont go past 6500 rpm...these arent magical numbers...this is mechanical engineering...