1. The most important thing about buying a new bike is to make sure it fits. The only way you'll know if the bike is right for you is to size up the bike and make sure that the bike's geometry matches your body's geometry. Ask questions and do some research.
mtn. biking 101
2. If possible, try to find a shop that will let you demo the bike on real dirt. Five minutes in a parking lot won't cut it. You wouldn't buy a car without a real world test drive, and a bike should be no different.
3. Don't belive the hype. Just because your favorite rider or best friend rides a certain bike, that doesn't mean that's the best one for you. Have an open mind and be realistic about your needs and ability.
Results 1 to 6 of 6

Thread: Bike Sizing

  1. #1
    mtbr member
    Reputation:
    Join Date
    Nov 2013
    Posts
    3

    Bike Sizing

    Im a little confused on the sizing aspect to bike frames. I have a 2013 CAAD8 road bike currently. It's a 54cm frame. I am 5'11" with a 34" inseam. Doesn't that seem like it might be a bit small? I bought it at my local LBS, but anyway.

    Now i'm looking to buy a MTB for the winter and i'm not sure if I should go with a 17" or a 19" frame.

    Any suggestions?

  2. #2
    mtbr member
    Reputation:
    Join Date
    Oct 2013
    Posts
    46
    Quote Originally Posted by yoshisakan View Post
    I have a 2013 CAAD8 road bike currently. It's a 54cm frame. I am 5'11" with a 34" inseam. Doesn't that seem like it might be a bit small? I bought it at my local LBS, but anyway.
    Sounds about right to me. Your inseam is proportionately long compared to your height, which means your torso is probably short, so a smaller frame with a shorter top tube makes sense. More important is how you feel on the bike.

    Can't give much advice regarding mtb sizing, but I'm sure others will chime in.

  3. #3
    Fat-tired Roadie
    Reputation: AndrwSwitch's Avatar
    Join Date
    Nov 2007
    Posts
    13,523
    Does the road bike feel like it's the wrong size?

    Try both 17" and 19" mountain bikes. It's actually not to dissimilar from road sizing - you don't want too much weight on your hands, it shouldn't maul your back, it shouldn't nosedive when you ride off a curb, and the front wheel shouldn't wander all over the place when you ride up a hill.

    That's assuming you're looking at a XC or trail bike. For more downhill or stunts oriented types of riding, people often make a different set of compromises.
    "Don't buy upgrades; ride up grades." -Eddy Merckx

  4. #4
    mtbr member
    Reputation:
    Join Date
    Nov 2013
    Posts
    3
    Maybe I'm over thinking it. I don't really get any back pains or anything until the 20 mile mark, but that's probably from lack of experience rather than fitment. What do you think would be the mtb equivalent of a 54cm road bike?

    This bike will be used for winter travel and exercise. I live in Cleveland so we get our fair share of snow on the lake. That being said, I think I want a 29er. I feel like they will be better in the snow.

  5. #5
    Fat-tired Roadie
    Reputation: AndrwSwitch's Avatar
    Join Date
    Nov 2007
    Posts
    13,523
    I think it's hard to draw a good equivalency between mountain bikes and road bikes. Drop bars muck things up.

    For myself, I ride a 52 cm road bike and ride a 17" mountain bike. Give or take. A less "squishy" way to express it would be to say that my road bike has a 535 mm top tube and my mountain bike has a 597 mm top tube, though my old one has a 590 mm top tube; I think differences in seat tube angle account for that. Anyway, by this comparison, one might say that a mountain bike should have about 60 mm more top tube than a road bike. If you look at how much further forward of the handlebar clamp you put your hands on a road bike by riding in the brake hoods, you'll see where this idea comes from.

    The problem is that mountain biking and road cycling aren't quite the same thing. I ride in a pretty racy position on my mountain bike, but I still sit a little higher than I do on my road bike. The difference was a little greater on my previous mountain bike. So while I'd be surprised if a rider rode a big mountain bike but preferred little road bikes, or vice versa, for someone to come in and contradict my statement about 52 cm road bikes and 17" mountain bikes wouldn't surprise me, and I wouldn't really even be able to disagree - I think it's not a very reliable statement, just a starting point.

    Another problem, and one that you're probably already aware of, is that not all 52 cm road bikes are the same. Not all 17" mountain bikes are the same either. There're probably some road bikes out there that I'd want in a 54, and some I'd want in a 50. By the numbers, I expected to want my new mountain bike in a 16, but have ended up with an 18 (Kona skips 17" in their nominal sizing for this model.)

    I guess about the best I can really tell you is to start with 19" bikes and try a size up and a size down.

    Are you going to be doing any mountain biking?
    "Don't buy upgrades; ride up grades." -Eddy Merckx

  6. #6
    mtbr member
    Reputation:
    Join Date
    Nov 2013
    Posts
    3
    Well, after looking extensively for a week, I managed to find a really good deal on a 2013 Trek Cobia 29er 19". It's a little more than $600 and I can pick it up locally. After reading reviews, it seems to have a really nice air fork and sram components.

    I'm not planning to do any mountain biking, but i'm not going to rule it out either. I like to stay active in the summer between road biking and kayaking, so i'll probably look into mountain biking too. To be honest though, I don't know too much about it.

Similar Threads

  1. Not sure of my bike sizing
    By trek88 in forum General Discussion
    Replies: 4
    Last Post: 05-05-2013, 05:29 AM
  2. DJ bike sizing?
    By Whip Chop! in forum Urban/DJ/Park
    Replies: 5
    Last Post: 01-14-2013, 07:12 PM
  3. Bike sizing?
    By Eyetattoo in forum Beginner's Corner
    Replies: 23
    Last Post: 08-23-2012, 10:31 PM
  4. DH Bike sizing
    By HelloMyNameIsSean in forum Downhill - Freeride
    Replies: 15
    Last Post: 11-20-2011, 02:33 PM
  5. DH bike sizing
    By manamana in forum Downhill - Freeride
    Replies: 8
    Last Post: 02-20-2011, 01:52 PM

Posting Permissions

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