Discussion in 'Bicycle Mechanics and Repairs' started by yenrod, 5 Jun 2008.

  1. yenrod

    yenrod Guest

    Anyone know the spin out speed of this gear combo...


    The other day I was doing 30mph and it still 'hard' to pedal... :angry:
  2. Smeggers

    Smeggers New Member

    Spin out on me 53x13 all the time.

    Gravity has to assist of course!
  3. OP

    yenrod Guest

    I had this ratio 13-24 9sp block but now its a shimano 12-21 (self made) and theirs quite (a massive) a difference between a 12 and a 13 !!!!
  4. Will1985

    Will1985 Über Member

    South Norfolk
    http://www.sheldonbrown.com/gears/ says that you'll be doing 50kmh at 90rpm and 55kmh at 100rpm.

    I had this yesterday trying to spin round at 110rpm in 50x12 doing about 55kmh, so it sounds about right.
  5. Joe24

    Joe24 More serious cyclist than Bonj

    There wa a better link on Sheldons page, but all i could find was his one.
    Put the stuff in and see.
    Still cant find the link to the otherone i was thinking of.
    Edit: Will beat me to it :biggrin:
  6. piedwagtail91

    piedwagtail91 Über Member

  7. Chris James

    Chris James Über Member

    My top gear is 52x12 which is pointlessly high in my opinion. For downhills above 35mph or so I go into an aero tuck anyway as I think I am faster as well as using no energy.

    I can't imagine ever spinning out a 53/12. If we are saying 35mph for 100 rpm then that is pretty quick and most people would consider spinning out to be way above 100 rpm. So, I don't know 50mph before spinning out?
  8. dodgy

    dodgy Guru

    Which is the reason I have a compact, it's very rare I manage to spin out 50/12 and if I am able to spin it out, it means I'm descending anyway.

  9. Chris James

    Chris James Über Member

    Mine's a triple:biggrin:

    But I agree , which is why I suggested on the compact thread that a 50/39/30 triple makes more sense to me than a 52/42/30 albeit that there are lots of duplicated gears on triples so having gears that are 'too high' is less of a drama.
  10. OP

    yenrod Guest

    You cant get the power with 'compacts' as you can with normal sized rings..wear out quicker too !
  11. fossyant

    fossyant Ride It Like You Stole It!

    South Manchester
    I don't often get the need to spin a 53 x 13, as that's into tuck speeds at high revs.........certainly not in the UK and I am in the Peak's - far faster speeds are achieved by removing brain, depositing it in your rear pocket, and GOING FOR IT in a TUCK POSITION........ or brown pant's "ing" it !!
  12. bonj2

    bonj2 Guest

    over 40mph. My 'terminal' velocity (on any hill i've tried so far anyway) is about 42mph and i find my top gear of 52x11 (which is higher than 53x12 btw) is about right for that.
    My spinning out speed for my middle ring (42x11) is about 30mph.
  13. hubgearfreak

    hubgearfreak Über Member

    i'd be interested to hear you theory to back up the first bit of this claim?

    as for the second bit, how much quicker will a 50 toothed chainring wear out compared with a 52...that's right, a whopping 4%
  14. bonj2

    bonj2 Guest

    you can't play cards without the ace of spades and the ace of hearts.

    never thought of that 'tuck' method being faster than pedalling, but will have to have a go, sounds like it may be worth a try.
  15. hubgearfreak

    hubgearfreak Über Member

    it'll depend upon the gradient of the slope of course. and wind speed and direction.. although wind speed and direction would be irrelevant after a certain, steepness of gradient

    if you knew a chap knowledgeable in physics, he could probably work it out, or just trial and error.

    as for your 42 being the max, is it through fear or just wind resistance? i once recorded 46.9mxs, and i'm sure that won't be the fastest
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