Advertise on Bikeforums.net



User Tag List

Results 1 to 12 of 12
  1. #1
    Senior Member
    Join Date
    Apr 2005
    Location
    MD
    Posts
    773
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)

    fixed gear training question: crank length

    Lots of fixed-gear riders (Sheldon Brown, and the crowd form the SS/fixed forum) would suggest that running 165mm to 170mm cranks are the norm (faster spinning, less risk of pedal strike, etc.) But if the goal is just fixed gear training for road racing, should your crank arm length be different from your road bike?

    I'm asking because I ride 175mm arms on my road bikes, and I don't like the idea of having my fixed gear bike fit differently...

    Thx.

  2. #2
    Senior Member gfrance's Avatar
    Join Date
    Mar 2006
    Location
    New York City
    Posts
    1,757
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Might depend on the geometry of the bike. Most track bikes have a higher bottom bracket and because of that some prefer a slightly shorter crank. But unless you're worried about pedal strike, I'd say run the 175s. Shouldn't be a problem if you're careful on corners. (I've never once had a real pedal strike. A few times, on clips and straps, the edge of the strap just barely brushed the ground. That feedback alone was enough for me to just gauge it from then on).

  3. #3
    In beaurocratic limbo urbanknight's Avatar
    Join Date
    Mar 2006
    Location
    Los Angeles, CA
    My Bikes
    Specialized Allez, K2 Razorback
    Posts
    22,457
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    The higher bottom bracket shouldn't affect crank arm choice. It's just there for better pedal clearance (on a velodrome). I'd say stick with 175s if you just want to train on the road, but if you're looking to practice spinning at a high cadence, you'll have an easier time with that on shorter cranks.
    "Well, I guess you can cut the arts as much as you want... Sooner or later, these kids aren't going to have anything to read or write about." (Richard Dreyfus as Glenn Holland)

  4. #4
    Senior Member bitingduck's Avatar
    Join Date
    Jan 2005
    Posts
    2,946
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    The higher BB will also help with pedal clearance on the road-- it's helpful at low speed in the corners on a track, but at higher speeds in turns on the road (when the bike is leaned over).

    I'm not sure it's that big a deal to switch crank lengths. I ride 172.5 on the road, and 165 on the track, and probably half my mileage (and almost all my racing) is on the track. It's usually not that noticeable, and only takes a few minutes to adjust usually.
    Track - the other off-road
    http://www.lavelodrome.org

  5. #5
    Blast from the Past Voodoo76's Avatar
    Join Date
    Mar 2005
    Location
    Schertz TX
    My Bikes
    Old ones
    Posts
    2,474
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Same, 172.5 on the Road, 165 on the Track. Really doesn't feel that much different.

  6. #6
    half man - half sheep Doggus's Avatar
    Join Date
    Apr 2005
    Location
    Allen (Dallas), TX
    Posts
    2,452
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    175 road
    170 track

    Somewhere I read crank length is over-rated. I believe it.


    chuckle chuckle
    "The cycling community is so small that it is nearly inbred." - Steve Tilford

  7. #7
    cmh
    cmh is offline
    Senior Member
    Join Date
    Jul 2005
    Location
    Portland, OR
    Posts
    2,263
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    I use 175 mm cranks on the road and had a winter bike with 170mm cranks. I could definitely feel the difference, and I tended to pedal a cadence of 5 or 10 rpms higher with the shorter cranks. So, in the name of specificity of training I put 175mm cranks on the winter bike. When I got a track bike with 165mm cranks for winter training, I made the same switch. It makes the transition back and forth from bike to bike feel less weird.

  8. #8
    raodmaster shaman
    Join Date
    Dec 2004
    Location
    G-ville
    Posts
    1,431
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    if you are going to be out on country roads where you wont have to worry about pedal strike, go with the 175's if that what already feels good.

  9. #9
    this portrait of karma transplant's Avatar
    Join Date
    Aug 2005
    Location
    chicago
    Posts
    1,238
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    175 road
    170 track

    same

  10. #10
    Because I thought I could ks1g's Avatar
    Join Date
    Dec 2004
    Location
    Wash DC Metro
    My Bikes
    November, Trek OCLV, Bianchi Castro Valley commuter
    Posts
    969
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    With a fixie, it's also about being able to maintain a faster cadence 'cause you don't have a choice. Minor case in point - late last season, I was commuting home on my fixie when one of the faster groups from the local weeknight hammer ride passed me. I decided, heck it's mostly downhill on this stretch and I should be able to keep up with them until I hit my turn off - and with a commuting rig complete with a mirror and fenders, it'll be my personal FRED moment. Too bad my legs refused to do the necessary rpm! I even kept looking for a taller gear as I spun out and watched the ride pull away.

    Shorter cranks should let you pedal at a little higher cadence.

  11. #11
    Senior Member Dubbayoo's Avatar
    Join Date
    Feb 2006
    Location
    Atlanta
    My Bikes
    Pedal Force QS3
    Posts
    7,683
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by bitingduck View Post
    The higher BB will also help with pedal clearance on the road-- it's helpful at low speed in the corners on a track, but at higher speeds in turns on the road (when the bike is leaned over).

    I'm not sure it's that big a deal to switch crank lengths. I ride 172.5 on the road, and 165 on the track, and probably half my mileage (and almost all my racing) is on the track. It's usually not that noticeable, and only takes a few minutes to adjust usually.
    +1. I go between 165's on the track and 170's on the road and I don't think about it when I'm riding. My opinion is you should go smaller on fixed. I would say 170's but it's your bike.

  12. #12
    Mitcholo CrimsonKarter21's Avatar
    Join Date
    Aug 2006
    Location
    Oost Vlaanderen in mind, Cleveland in body
    My Bikes
    2010 Mitcholo w/ Sram Force/Red
    Posts
    8,851
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Don't go with a 165, because you'll love it so much that you'll want one for your road bike.

Posting Permissions

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