Quantcast

SS 29 Inch Wheel - Gearing Question

Discussion in 'Cross Country, All Mountain & Trail Riding' started by Old_Dude, Oct 18, 2005.

  1. Old_Dude

    Old_Dude Monkey

    Rep/Likes:
    4 / 0
    Joined:
    Nov 13, 2001
    Messages:
    474
    Location:
    ~40 min. from the closest trails
    I was told a 32-18 on a 29 inch wheel was about the same as a 32-16 on a 26 inch wheel.

    Does anyone have more info - like an Excel spreadsheet for numbers?

    Thanks,

    OD
     

    Please register to disable this ad.

  2. BikeGeek

    BikeGeek BrewMonkey

    Rep/Likes:
    5 / 51
    Joined:
    Jul 2, 2001
    Messages:
    4,402
    Location:
    Hershey, PA
  3. MMcG

    MMcG Ride till you puke!

    Rep/Likes:
    5 / 4
    Joined:
    Dec 10, 2002
    Messages:
    15,466
    Location:
    Burlington, Connecticut
    OD you got that Surly up and running yet??

    I'm waiting on delivery of a used one hopefully by week's end! :)
     
  4. Meat Foot

    Meat Foot Monkey

    Rep/Likes:
    5 / 0
    Joined:
    Mar 24, 2004
    Messages:
    269
    Location:
    On the asthenosphere
    Sounds right, I have heard adding 2 teeth in the back is about the same G.I.

    Cheers!
     
  5. ridetoofast

    ridetoofast scarred, broken and drunk

    Rep/Likes:
    6 / 0
    Joined:
    Mar 31, 2002
    Messages:
    2,093
    Location:
    crashing at a trail near you...
    G.I. = ((number of teeth on chain ring)/(number teeth of sprocket))*Diameter of Tire
     
  6. Old_Dude

    Old_Dude Monkey

    Rep/Likes:
    4 / 0
    Joined:
    Nov 13, 2001
    Messages:
    474
    Location:
    ~40 min. from the closest trails
    Thanks everyone for the comments - I appreciate the info.



    YES!!!! And, I love it!!!! Really, I enjoy it more than I'd imagined. It's a whole new way of discovering the sport - I think I'm a born singlespeeder.

    The steel frame & 29 inch wheels are really nice.
     
  7. slowSSer

    slowSSer mnoeky

    Rep/Likes:
    5 / 0
    Joined:
    Aug 14, 2002
    Messages:
    553
    Location:
    Stepford
    im not even sure i should reply....but i will anyways.

    ratios:

    26"wheels:
    175mm cranks
    34:20

    29"wheels"
    180mm cranks
    33:21

    feels perfect to me.

    I've always heard that there's a 10% difference between 26ers and 29ers, but i believe that deals with only the wheel size....so all of this is mute, due to gearing.

    too much asbestos and lead today- i'll shut up now.
     
  8. riderx

    riderx Monkey

    Rep/Likes:
    6 / 0
    Joined:
    Aug 14, 2001
    Messages:
    704
    Location:
    Fredrock
    The rough rule of thumb is to add two teeth in the rear for the equivalent 29er gear. But the gear inches will help you nail it exactly. For the 26" I run 34x17 (2:1) and on the 29" I use 36x20. Both work out to be 52 gear inches.
     
  9. Old_Dude

    Old_Dude Monkey

    Rep/Likes:
    4 / 0
    Joined:
    Nov 13, 2001
    Messages:
    474
    Location:
    ~40 min. from the closest trails
    I have a 33 tooth chainring, 18 cog and 29 inch wheel - not counting the final diameter with the tire - that means my GI = ~53.2. Compared to where I've been - and my destination - I'm currently not in very good shape. Based on many of the trails I've ridden thus far, this bike seems geared "low", but the GI seems a bit higher than the "standard" 52. The bike shop sold me 180mm cranks, but I'm still unsure how the crank length would fit into the equation . . . :confused:

    . . . this is too much analysis for me . . . I think I'll just go riding and enjoy what's hooked up and rollin'.

    :)

    Happy ridin' ya'll,

    OD
     
  10. riderx

    riderx Monkey

    Rep/Likes:
    6 / 0
    Joined:
    Aug 14, 2001
    Messages:
    704
    Location:
    Fredrock
    29 inch is the diameter counting the tire. As far as crank lenght, Sheldon Brown has a calculator that uses crank length to come up with a number he calls gain ratio. Good for comparing the numbers.
     
  11. Old_Dude

    Old_Dude Monkey

    Rep/Likes:
    4 / 0
    Joined:
    Nov 13, 2001
    Messages:
    474
    Location:
    ~40 min. from the closest trails
    I probably knew that earlier in life . . . I'll blame my forgetfullness on old age . . . (sigh)