In an old post JB wrote: ____________________________________________ So far, each Octalink failure I've come across was due to a Shimano oversight. Shimano had two shots at this. First it designed them so that there was no press-fit i.e. thespline simply lined up, fitted in and was tightened. Unlike a square taper that press-fits quite tightly. A spline that doesn't press-fit has a tendency to cause what iscalled an elastic backlach, a phenomena that destroys the splines on the softer of the two materials. This just happens to be the crank, which just happens to be the most expensive of the two materials. It was very common on the crappiest car ever made by the British -the MG and its ilk. They had spline-fit wheels with knock-on centre nuts that looked like propellers. These continuously destroyed themselves by backlash. This backlash then caused the retaining bolt to loosen, which worsened the backlash. On bicycles with Octalink, this wasparticularly evident with goofy-footed riders. Goofy-footed means right-footed, you'll descend with your right foot forwards rather than the other 75% of the population that'll go left-foot forward. Left-footedness is more prevalent than left-handedness (10%). Shimano then went to the other extreme and redesigned theirsplines by making them longer (which wasn't the problem in the first place, press-fit was) and unfortunately making them blind, so that you can't see them line up. Because the second attempt was a press-fit, they were supposed tobe hard to torque down. Aluminium is soft and if the splines aren't aligned, you're blissfully unaware that you're re-shaping the splines whilst torqueing it to Shimano's spec. Bad design. Period. The ISIS consortium understood the problem and designed their splines right from day one. Shimano created a mess whilst trying to fix the problem and at onestage you needed a compatibility table to see what fits with what. It was a mess. They then abandoned the concept completely and opted for theone-piece right crank and spindle, and a pinch-fit splined crank on the left. Therefore, don't blame yourself or the mechanic for the destroyedcrank. It is an accident waiting to happen. I suggest you go to a different crank system now that you're in the market for a crank. JB____________________________________________ What needs to be done to convert from Octalink to the Hollowtech system? CRC have a Shimano LX Chainset HollowTech II M582 at R723, while my BB alone cost around R337 (R400 from LBS) so the conversion would make sense if it can be done easily while not sacrificing reliability. (The Octalink has served me well, but is time to replace the BB & chainrings.)