Advertise on Bikeforums.net



User Tag List

Results 1 to 7 of 7
  1. #1
    Bread
    Join Date
    May 2009
    Location
    Madison, WI
    My Bikes
    Steamroller | Langster
    Posts
    22
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)

    Crank arm lengths?

    Apart from my n00bness...

    Why do MTBers prefer longer crank arms? What are the benefits?

    I'm coming from road biking, and 165mm crank arms are just a few to choose from from the market. Standing at 5'7" with an inseam of 29", my 175's are killing my uphill. Out of shape I am maybe?

  2. #2
    Senior Member
    Join Date
    Aug 2009
    Location
    Madison, WI
    Posts
    2,504
    Mentioned
    3 Post(s)
    Tagged
    0 Thread(s)
    Cool, you're in Madison. Where do you ride?

    In any case, I'm also 5'7"(not sure of inseam) and have 175s on my bike. 175s on my road bike make my knees pay, but it seems to be OK for MTBing. It took a little getting used to, and I found at first that my knees would get a little unhappy if I didn't have my seat at the highest height possible when sitting and riding. I did get used to it, though, and now everything is fine. The reason MTBers prefer longer crank arms is for leverage purposes. You can achieve that same thing with larger cogs in the rear. If you prefer 170s or 165s, go for it. They'll give you slightly better pedal clearance anyway. I would think that you'll get used to the 175s if you decide to stick with them for a little bit.
    Last edited by 3speed; 04-30-12 at 04:52 PM.
    90 Miyata 914 with full Dura-Ace
    74 Ellis-Briggs, full butted 531
    80s Cierra Professional 5000, Tange Champion 2 and Shimano 600
    2011 New Belgium Cruiser
    Fetish Cycles "Discipline" built up with DJ2 fork and Shimano XTR, LX, Avid BB7.

    Quote Originally Posted by scyclops View Post
    Oh yeah, sure, what if everyone thought that way? Then internet forums would merely be places where rational people exchange useful information and ideas - instead of the chaotic, emotionally-charged circuses that they are.

  3. #3
    Bread
    Join Date
    May 2009
    Location
    Madison, WI
    My Bikes
    Steamroller | Langster
    Posts
    22
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    I just picked up a MTB last month, haven't had the chance to hit any single track trails yet

    If it's just leverage, I'm going for the 165's. I have a 9spd so it's a decent range. I did get used to the 175 after awhile, but going back and forth to the commuter, I'd rather keep my knees happy.

  4. #4
    Senior Member
    Join Date
    Aug 2009
    Location
    Madison, WI
    Posts
    2,504
    Mentioned
    3 Post(s)
    Tagged
    0 Thread(s)
    What part of Madison do you live in? I'd highly recommend Quarry Ridge. It's in Fitchburg right near the Target on PD. Totally free trails, a nice mix of everything from an XC loop, a free-ride style loop with big doubles, a nice big berm section, and a couple nice little beginner wooden features. Do you know about CORP? I'm just starting to get involved and went to one meeting so far. Cool people. There's a section in their forum that has some info on the local trails. I'm out at Quarry Ridge at least twice a week when this rain gives us a break. I'm a newbie too and not that great yet, so if you're looking for another newbie to ride a few laps with then feel free to say hello if you see a white Fetish Cycles bike, white fork, basically everything else black.
    90 Miyata 914 with full Dura-Ace
    74 Ellis-Briggs, full butted 531
    80s Cierra Professional 5000, Tange Champion 2 and Shimano 600
    2011 New Belgium Cruiser
    Fetish Cycles "Discipline" built up with DJ2 fork and Shimano XTR, LX, Avid BB7.

    Quote Originally Posted by scyclops View Post
    Oh yeah, sure, what if everyone thought that way? Then internet forums would merely be places where rational people exchange useful information and ideas - instead of the chaotic, emotionally-charged circuses that they are.

  5. #5
    Trail Blazing NoTrail's Avatar
    Join Date
    Sep 2008
    Location
    Louisville, KY
    My Bikes
    Roubaix, Epic, Source 11, Stumpjumper, Cannondale Tandem
    Posts
    232
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    I ride 175mm on my road bike, commuter bike, and tandem ... but I have 180mm on my mountain bike. Course, I'm 6'4" so it's not really an issue for me. The good part of longer cranks is better leverage. The bad part is less clearance when going over obstacles.
    Specialized S-Works Roubaix | Specialized Epic Expert | Specialized Source Eleven | Cannondale Road Tandem 2
    Watch the video of my West Coast Tour | Quest For Payne Website

    LIVESTRONG THINKSTRONG BESTRONG

  6. #6
    Pint-Sized Gnar Shredder Zephyr11's Avatar
    Join Date
    Nov 2007
    Location
    Somewhere between heaven and hell
    My Bikes
    '09 Jamis Komodo, '09 Mirraco Blend One, '08 Cervelo P2C, '08 Specialized Ruby Elite, '07 Yeti AS-R SL, '07 DMR Drone
    Posts
    3,498
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Hm. I don't know what causes this, but I've noticed it too. I have 165s on my road bike, which are fine. I have 175s on my mountain bike, which are also fine. And then I have 170s that came with my BMX bike and they are freaking tiny, and if I rode the bike more often I'd change them. I'm 5'3, forget inseam.

  7. #7
    Bike Junkie roccobike's Avatar
    Join Date
    Jun 2005
    Location
    South of Raleigh, North of New Hill, East of Harris Lake, NC
    My Bikes
    Giant OCR-C, Specialized Tarmac, Specialized Stumpjumper FSR, Stumpjumper Comp, 05 Rockhopper, 88 & 92Nishiki Ariel, 01 Bianchi Campione, 87 Centurion Ironman, 92 Paramount, 97 Lemond
    Posts
    9,001
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    I moved our Rockhopper to 170's from 175. On a fast course with no roots and only a few obsticles to deal with, its great and I hardly noticed the difference except the bike seemed more responsive. On a slower, more technical course with lots of roots, it was a pain. The comment about clearance is a good one cause I did notice that difference.
    Roccobike BF Official Thread Terminator

Posting Permissions

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