• 09-24-2016
    thumper8888
    Steer clear of rotor cranksets ....
    I just had the second one crack on me in less than a year. Not a huge cohort for data, but still, I've owned two now and both broke.
    The non-driveside arm cracks at the very far end away from the pedal, essentially opening all the way to the spindle. You know it's done this when the crank starts creaking.
    Good times. It's frustrating because Cervelo hasn't left us with many options. My gut is to go Shimano but I hate the idea of using the adaptors, and I run QXL rings, so I'd have to go out and buy $240 worth of new four-arm rings, too.
    FSA reportedly has its own issues. Kind of a mess.
  • 09-24-2016
    OldChipper
    Enduro Torqtite for BBright is a full-on external bearing BB that will let you use Shimano or other 24mm cranksets. Been using one on my R3 for a while now with a DA-9000 crank.

    Enduro TorqTite BBRight to 24mm Angular Contact Steel Bearings - Enduro Bearings Online

    They also have ceramic if that's your preference.

    You only need one of their special wrenches (ordered separately) as a standard Shimano BB tool works fine on the other side. The NDS site pretty flush to the BB shell so it's tougher to use a Shimano BB tool on that side, but you can try if you don't want to order the Enduro tool.
  • 09-30-2016
    thumper8888
    The enduro angular bearings are good stuff. And I carefully considered Shimano. But I run oval rings, and for current Shimano I would have had to buy new, four-hole chainrings.
    So. A new crank, $240 or more for new chainrings, adaptor/bb bearings and next thing you know I'd be out $600 and have added 100 grams.
    Last night I put a new $225 SRAM S950 in it, shifted over the chainrings etc.
    The SRAM crank, which is what, their third-tier model after Red and Force? Fourth tier? I dunno... but it weighed 23 grams more than the much touted Rotor crank it replaced, just weighing arms/spider/spindle in each case.
    Rotor definitely overhyped (and overpriced) for quality and weight.
  • 09-30-2016
    MMsRepBike
    Any pictures of these failures?
  • 09-30-2016
    thumper8888
    I can surely pull the latest one out of the recycling bin where I dunked it last night and post one. May even have the other in a box somewhere. But there's no magic to it. Arm simply cracked completely through to the spindle... you know, kind of like where the "attachment" opening of the arm would be if it were a shimano.
  • 09-30-2016
    MMsRepBike
    I hear what you're saying, just haven't seen it myself. I see a lot of Rotor cranks too, they're on a ton of bikes OEM. I've been riding a set for about 4k miles with zero issues. Poor crankset has been through hell too but it's been about the most solid part of the whole bike.
  • 09-30-2016
    thumper8888
    Will try to remember to yank it out of recycling tonight and shoot it. If I can only find the one, that will cover it, since they were essentially identical.
    There are several photos out there, and one of the entire arm snapping off just below the spindle, but that one I count as an outlier.
    I think DC rainmaker had one go in pretty spectacular fashion. Neither of mine stopped a ride even. May have even lasted a few more but wouldn't want to try.
    I'm a sprinter, but not at spectacular one at 1400 watts.... so its not that, and Im not out of the saddle much living where I do, so they aren't getting abused.
    On another note, have you noticed unusual corrosion on yours? this one had a bit, and I noticed quite a lot on chainring bolts when I pulled them, just from the past 5-6 months.
    Ditto the SISL2 on the other bike. The actual flat surfaces on the arms... and those things have thin sheet alloy arms, so they won't stand much of it.
    We don't salt the roads here, and the only thing I can figure is that there is some weird electrolysis going on with the weak currents from the power meters... but one is a stages and I'd think it's isolated from the metal by epoxy.
    Have seen bizarre things with the combination of carbon boats, alloy parts and even the faintest of electrical currents though.
  • 10-01-2016
    thumper8888
    2 Attachment(s)
  • 10-05-2016
    aclinjury
    damn that's bad
  • 10-18-2016
    llbr22
    Did you get these replaced via warranty? (Was the 2nd crank you mentioned a replacement?)


    Sent from my iPhone using Tapatalk
  • 10-20-2016
    thumper8888
    Quote:

    Originally Posted by llbr22 View Post
    Did you get these replaced via warranty? (Was the 2nd crank you mentioned a replacement?)


    Sent from my iPhone using Tapatalk

    No, the first crank came with the frameset used to a minor degree, but def used. Long story, but the frameset was a crash replacement someone sold instead of riding and he tossed in the crank as part of the deal.
    So, the second one I had to buy rather than get replaced.
    I actually called Rotor to ask if they would replace the arm at cost, cot plus 10 percent or something since this (google around a bit) has become a common problem with their cranks. He cheerfully quoted me what sounded like a retail-plus price for a replacement arm, a price higher that the cost of an entire new Rotor crank off eBay.
    Rush, meet mistake. I bought another rotor.
    The SRAM is running fine so far, maybe 350 miles on it.
  • 03-09-2017
    gurk700
    Stop being too strong man