Working on Campagnolo Power Torque cranksComments
by Mark V on Aug 19, 2011 at 6:54 PM
Once upon a time, I was an Italia-phile… I had an Italian bike with Italian saddle (Selle San Marco), Italian pedals (Diadora), Italian shoes (of course), a Northern Italian/Romanian girlfriend (gorgeous), and I had cycling components from one of the most revered names in the industry, Campagnolo. I could go on and on about the history and the mystique of the company founded by Tullio Campagnolo, but soooooo many others have already done it……. and I’m tired of drinking KoolAid.
I’m going to come right out and say that this is a ridiculous design. Essentially, Campagnolo tried to keep the aesthetics and bearings of their UltraTorque cranks (Record, SR, Centaur, etc) while ditching the UltraTorque’s central Hirth joint connection. The only plausible reason would be to lower the cost. On the other hand, using the same bearings and similar seals as the more expensive cranks is probably the worst decision, as the UltraTorue cranksets are prone to short bearing life. Much like the UltraTorque cranks, the PowerTorque cranks use a spring washer to preload the bearings, though the PowerTorque cranks use a much more substantial spring. Though the bearings seem to be identical to the more expensive cranks, they mount differently. UT cranks have a bearing press fit onto each half of the spindle between the Hirth joint and the crankarm. For both PT and UT cranks, a C-clip catches the drive side bearing into the cup, but the PT nondrive bearing is pressed into the cup instead of onto the spindle. Thus PT and UT bottom brackets are not interchangeable.
The left crankarm fits onto the splined spindle with a large fixing bolt. How large? It takes a 12mm allen wrench…..cause that’s convenient (for those of you who don’t touch bike tools, this statement is sarcasm). Oh, but the real fun is trying to remove the crankarm. That’s because the bolt is not self-extracting. Since the PT arm mimics the UT arm, there just isn’t enough room to contain a self-extractor like on SRAM road cranks. Instead, the Campagnolo instructs you to use their PowerTorque tool kit and a gear puller. I’m a bike mechanic, and I didn’t even know what a gear puller is….that’s because it’s a fucking automotive tool. And the so-called “tool kit” consists of a plug to insert into the end of the bb spindle (so to give the gear puller something to push against) and a thin cardboard pad so you don’t scratch your precious cranks where the gear puller grabs onto the back side of the arm. Except that the thin pad is still thick enough to prevent the claw of the gear puller to fit between the arm and cup. In fact, I had to sculpt/grind the gear puller to fit even without the pad.
It’s ironic that in the good ol’ days, Campagnolo used to make THE professional bicycle tool kit and now they make tools out of cardboard and crankarms that make cotter pins look sophisticated. The new Athena PT crankset is shiny silver alloy, which means that unsuspecting consumers will buy it because it looks retro compared to all the carbon cranks currently on the market. I would say that is a mistake on their part.
Above is the so-called “tool kit” sold by Campagnolo for the PowerTorque cranks. Expensive and almost useless. I modified the plug with a central hole to catch the driver on the gear puller, prevent the puller from sliding off as I tensioned it.
Above you can see the C-clip that holds the drive side bearing in the cup and the spring washer that provides the bearing preload. Also, you can see the fixing bolt that requires a huge 12mm allen wrench to tighten.
The drive side bearing is pressed onto the crankarm spindle and further secured with a thin C-clip like the UltraTorque cranks. Also like the UT cranks, consumers who own PT cranks are likely not going to be able to change the bearings at home.
The bolt doesn’t self-extract the crankarm. Who the hell designed this? I had to buy automotive tools and then heavily modify them just to service the crank. Your typical home mechanic is just completely screwed.
Notice in the above shot how I’ve ground and then pseudo-polished the claw of the gear puller. I had to thin out the claw just get it on the crank.