Advertise on Bikeforums.net



User Tag List

Results 1 to 11 of 11
  1. #1
    Junior Member
    Join Date
    Sep 2011
    Posts
    9
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)

    What gear ratio will feel the same?

    I'm building a fixie. Right now I ride a SS 29er mountain bike geared 33-16. The smaller chain ring on my old road bike's crankset has 39 teeth, so I'm wondering what size sprocket I should run to get a little more power than that.

    I'm not sure on the crank size, they seem similar. I'll be running 700c on my fixie. I'm not too concerned with the force it'll take to pedal, my legs will acclimate themselves to that, I just want the same top speed or a little more even.

    I've tried looking at gear conversion calculators and searching, but I've had no luck.

    Thank you.

  2. #2
    Cat Enthusiast ddeadserious's Avatar
    Join Date
    Aug 2011
    Location
    Plymouth, MI
    My Bikes
    All City Nature Boy
    Posts
    2,326
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    33/16 on a 29er is 59GI.

    59GI is pretty low for a road fixed gear. It's generally advised to start around 70-80GI. Perhaps since you're used to low gearing something in the high 60's would be good, such as 44/17, 46/18, 49/19, etc.
    ALL CITY NATURE BOY

  3. #3
    Junior Member
    Join Date
    Sep 2011
    Posts
    9
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    The thing is, unless I want to swap out my whole crankset I'm stuck with using a 39 tooth chain ring to achieve a decently straight chain line. How small of sprockets do they make that are still compatible with track wheels?

  4. #4
    Senior Member LessonLearned's Avatar
    Join Date
    Jun 2012
    Location
    Chicago
    My Bikes
    http://www.pedalroom.com/bike/2008-se-lager-brown-6612
    Posts
    774
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by Muggle View Post
    The thing is, unless I want to swap out my whole crankset I'm stuck with using a 39 tooth chain ring to achieve a decently straight chain line. How small of sprockets do they make that are still compatible with track wheels?
    39/15 would be a great starter gear. I'm no expert, but I am a beginner, and 69 gear inches is what I run (44/17), and that's what 39/15 works out to.
    Last edited by LessonLearned; 07-02-12 at 10:19 AM.
    Quote Originally Posted by seau grateau View Post
    "Hold it right there, son. You know why I pulled you over? Let me see you whip-skid that sweet fixie."
    PedalRoom

  5. #5
    Junior Member
    Join Date
    Sep 2011
    Posts
    9
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Great, thanks!

  6. #6
    Cat Enthusiast ddeadserious's Avatar
    Join Date
    Aug 2011
    Location
    Plymouth, MI
    My Bikes
    All City Nature Boy
    Posts
    2,326
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Sorry, I didn't realize you were converting an old road bike. LessonLearned is right, 39/15 should do the trick.
    ALL CITY NATURE BOY

  7. #7
    7-speed doomsday prepper ThermionicScott's Avatar
    Join Date
    Aug 2011
    Location
    CID
    My Bikes
    1991 Bianchi Eros, 1964 Armstrong, 1988 Diamondback Ascent, 1988 Bianchi Premio, 1987 Bianchi Sport SX
    Posts
    8,124
    Mentioned
    6 Post(s)
    Tagged
    0 Thread(s)
    Since you're used to a lower gearing, and cogs aren't *that* expensive, it wouldn't hurt to start with a 17T or so, get your knees used to it, then move to smaller cogs as your skills improve.

    I used ~60 GI on the road for a while before moving up to 65, then 69, where I'll most likely stay.

    - Scott
    Quote Originally Posted by chandltp View Post
    There's no such thing as too far.. just lack of time
    RUSA #7498

  8. #8
    Quirky Grifter LesterOfPuppets's Avatar
    Join Date
    Sep 2008
    Location
    Vancouver, USA
    My Bikes
    My War
    Posts
    20,132
    Mentioned
    44 Post(s)
    Tagged
    7 Thread(s)
    I personally like a higher gear for fixed road riding than for SS trail riding.

    MTB = 34x17 on 26x2.1"
    Fixed = 43x16 on 700x28c.
    1980ish Free Spirit Sunbird fixed * 1996 Mongoose IBOC Zero-G * 1997 KHS Comp * 1990-ish Scapin * Lemond Buenos Aires Triple

  9. #9
    Senior Member
    Join Date
    Aug 2010
    Posts
    488
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Just check here for exact ratios and info...

    http://software.bareknucklebrigade.c...it.applet.html

  10. #10
    Elitist carleton's Avatar
    Join Date
    Jul 2005
    Location
    Atlanta, GA
    Posts
    10,974
    Mentioned
    6 Post(s)
    Tagged
    1 Thread(s)
    When comparing bikes with different wheel diameters, you must compare meters/feet of development. Basically how far you travel per pedal stroke.

    A smaller factor in the feel will be the crank length. Longer cranks feel easier given the same meters of development. This is because you have a longer lever with which you are applying torque to the chain.

  11. #11
    Paste Taster Retem's Avatar
    Join Date
    May 2006
    Location
    Denver, Co
    My Bikes
    1970's kobe, Jury Bike, Dahon Boardwalk S1, Moto Outcast 29, Scrambler v3
    Posts
    4,390
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    dude use sheldonbrown.com/gears it is handy calculator you can plug in numbers for gears you like and compare
    I am dyslexic so bear with my posts.... [SIGPIC][/SIGPIC]

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •