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  • Turbine cinch woes (b.b. and q-factor)
  • ferrals
    Free Member

    Picked up new frame yesterday, realised race face don’t make pf41 bottom brackets. I’m sure I’ve read somewhere that people have struggled with non rf bb’s and cinch cranks (can’t think why?).

    All I’ve found so far is hope that do pf41 with 30mm axle, but not found them available on line any where. Any other ideas?

    In my googling I also realised the turbine cinch Q factor is 10mm wider than standard – explains why I’ve felt my feet were far apart on the few rides I had on old frame with them. Any thoughts on how much dig fence this actually makes? Bit annoyed I didn’t realise or I’d probably not have bought them, already having knee issues.

    jabbi
    Free Member

    What you need is a Cinch Bb92 available through Silverfish. 36.99

    ghostlymachine
    Free Member

    Q factor, such as it is, could either cripple you. Or make absolutely no difference at all.

    I’m in the former camp. It needs to be fairly equal, and just at the right width. Too wide, too narrow or uneven gives me anything from mild discomfort, to agonising pain and a week of the bike. (While i source new cranks! )

    ferrals
    Free Member

    What you need is a Cinch Bb92 available through Silverfish. 36.99

    Thanks, I stupidly didn’t realise bb92 fitted 89.5mm shell with removal of a spacer.

    Q factor, such as it is, could either cripple you

    This is my worry, that I’ve made an expensive mistake – which will be even more expensive to fix. At the moment only ridden the cranks a handful of times and as mainly been riding the ‘cx bike not with sufficient regularity to develop pain. hopefully it will be fine, though irritating as the two bikes have different q-factors.

    dovebiker
    Full Member

    Non-issue for me – went from regular MTB cranks to 120mm spindle Turbine Cinch on my fatbike and I don’t have long legs. If I let my legs swing naturally, then the gap between my feet is about the same distance. I’ve ridden 200 miles straight-out without problems. If you don’t have any knee or foot-pedal alignment issues, then whilst it might feel odd at first, it doesn’t mean it’s bad. FWIW I’ve worked in lower limb medical prosthetics, so understand the biomechanics involved.

    digger95
    Free Member

    Remember standard Road cranksets and standard MTB cranksets have different Q-factors, lots of people seem to ride both without a problem. I found myself to be an exception to this as narrow road cranksets caused knee irritation. IIRC the difference is 17mm e.g. Shimano R – Shimano M.

    ghostlymachine
    Free Member

    hmmmm, only if you still subscribe to the narrow = better mantra, which has been thoroughly debunked on a regular basis for at least the last 7 or 8 years. Probably nearer 10.

    The right q factor is good, the wrong q factor is bad is about as far as it goes. (Not forgetting all the other geometrical gubbins that goes along with it. Pedals and shoes for starters.)

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