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 12 of 12

Thread: Bicycle sizing

  1. #1
    no trees are safe
    Reputation: Millfox's Avatar
    Join Date
    Jun 2012
    Posts
    490

    Bicycle sizing

    Hey guys.

    Due to my lower back spine disc problems I'm searching for a full susp. bike for XC rides and perhaps low level competitive marathon races. Unfortunately I'm a student so I can't quite afford a shining new ride. I Did run into a stock equipped 2011 Trek Fuel EX 8 which I could probably get down to about 900 EUR. But it's an 18,5" frame and I'm over 180cm tall. I do not know precisely how tall I am, but my older 17,5" HT bike barely fits with the saddle tube at max height.

    So the question is... is it a good size for me, and is it a good bike for general XC and Trail riding/racing? I know the info is quite vague, but I should be able to add more over time. Just ask what would you like to know and I'll do my best.

    Thanks!

  2. #2
    mtbr member
    Reputation: MSU Alum's Avatar
    Join Date
    Aug 2009
    Posts
    1,030
    Sizing: Fit Calculator - Competitive Cyclist
    Measure, insert, it'll spit out sizing info.

  3. #3
    mtbr member
    Reputation:
    Join Date
    Jun 2013
    Posts
    19
    Hey MSU alum you wouldn't happen to still be in the EL area would you?

  4. #4
    R.I.P. DogFriend
    Reputation: jeffj's Avatar
    Join Date
    Jan 2004
    Posts
    5,768
    Unfortunately, bicycles are usually sized by the length of the seat tube. One of the issues with this is that the total length, of the connection of the bottom bracket to the saddle, can be adjusted (with relatively few other side effects) by simply extending the seatpost. On the other hand, the top tube length cannot be extended with so few side effects. Yes, you can get a longer or shorter stem, but there are noticeable tradeoffs for doing so. And, you can move the saddle fore and aft, but there are also more side effects for doing this than there are for simply extending the seatpost.

    Also, with today's modern geometry, where a more sloping top tube is the norm which yields a wider range of riders that can comfortably use that frame, a given seat tube length is not IMHO as critical as the top tube length when sizing a bike to a rider. Further, a given size bike, even different models from the same manufacturer, can have top tube lengths that can vary as much as a couple of inches, and that is a HUGE difference that can make or break the fit to an individual rider.

    My advice would be to figure out what range of top tube length will work best FOR YOU, and start with those numbers as the start of whether a bike will work for you. After that, there are other considerations, but for me, that is the cornerstone of where to begin when determining whether or not a bike will fit me for it's intended use.

  5. #5
    mtbr member
    Reputation: HighFivenWhiteGuy's Avatar
    Join Date
    Apr 2011
    Posts
    129
    I am glad to see this thread as I had a few questions about sizing, and potential signs of a bad fit. I ride a 2012 Slash 9, size 21.5" virtual 20" actual. according to the size calculator that was linked to this bike is right on the money. However, about and hour and a half to two hours in my lower back starts aching fairly bad, mainly on descents. Does this seem like a sign of a bad fit? What about putting on riser bars to put me in a more upright position? Any tips or advice is greatly appreciated, thanks!
    Gotta love that government cheese...

  6. #6
    R.I.P. DogFriend
    Reputation: jeffj's Avatar
    Join Date
    Jan 2004
    Posts
    5,768
    Quote Originally Posted by HighFivenWhiteGuy View Post
    I am glad to see this thread as I had a few questions about sizing, and potential signs of a bad fit. I ride a 2012 Slash 9, size 21.5" virtual 20" actual. according to the size calculator that was linked to this bike is right on the money. However, about and hour and a half to two hours in my lower back starts aching fairly bad, mainly on descents. Does this seem like a sign of a bad fit? What about putting on riser bars to put me in a more upright position? Any tips or advice is greatly appreciated, thanks!
    Q: "Does this seem like a sign of a bad fit?"

    A: Not necessarily.

    For starters, I'd like to see a pic of your bike from the side and to know how tall you are.

    Interesting that you feel more back pain while descending than climbing (that's when I am most vulnerable to lower back pain if my saddle is too far back 1) relative to the bottom bracket 2) relative to the handlebar.

    Are you mainly standing while descending?

  7. #7
    mtbr member
    Reputation: MSU Alum's Avatar
    Join Date
    Aug 2009
    Posts
    1,030
    Quote Originally Posted by Borjawil View Post
    Hey MSU alum you wouldn't happen to still be in the EL area would you?
    The EL area? I'm a Utahrd...lots of wives and watered down beer.
    Last edited by MSU Alum; 06-23-2013 at 03:26 PM.

  8. #8
    mtbr member
    Reputation: HighFivenWhiteGuy's Avatar
    Join Date
    Apr 2011
    Posts
    129
    I am 6'2". While descending I am usually behind the saddle and low, standing with my knees bent. Here is a side shot.

    Bicycle sizing-2013-04-24_14-43-47_652.jpg
    Gotta love that government cheese...

  9. #9
    mtbr member
    Reputation: HighFivenWhiteGuy's Avatar
    Join Date
    Apr 2011
    Posts
    129
    And a pic while descending...
    Bicycle sizing-untitled.jpg

    Oh and Millfox...

    Treks are nice bikes. The fuel should be a good choice based on the type of riding you described. However you might want to try and find the next next level up travel-wise, the Remedy. The more travel your bike has the less shock your body will receive from obstacles on the trail. You might want to try a 29er as well. The big wheels should make for a smoother ride and less vibration on your back.

    Take your time and test ride every bike you can! As others have pointed out just going by size can be a bit misleading, see what feels right by riding it. I say this because I may have made that very mistake lol. Cheers and good hunting!
    Gotta love that government cheese...

  10. #10
    I like pie.
    Reputation: Mr5150's Avatar
    Join Date
    Dec 2011
    Posts
    434
    If fit is really important then go to reputable LBS where they do bike fitting and pay the fee.

    I had some issues with knee pain and low back issues. For $50 they found the problem. Money well spent. Price reflects the going rate 10 years ago in the SF Bay area.

    Advice on this fine forum is OK and worth every penny you paid.

  11. #11
    mtbr member
    Reputation: HighFivenWhiteGuy's Avatar
    Join Date
    Apr 2011
    Posts
    129
    What was the problem?
    Gotta love that government cheese...

  12. #12
    no trees are safe
    Reputation: Millfox's Avatar
    Join Date
    Jun 2012
    Posts
    490
    Thanks for the info guys. Unfortunately in my area there aren't that many mtn bikers and most bikes even when older are offered for 70-80% of their original price. Simply put... f*** that! Not worth it. This Trek bike has a very good price, unfortunately the person who sells it lives about 200 km away, which is quite a distance if you don't have a drivers license. I'll try to work this out with the owner and possibly LBS.

    Thanks for the info.

    And I did try a 29'' but it seemed large and clumsy for my trails, perhas it's about habbits but I'd rather stick to a size that is compatibe with my tire collection.

    I'll post progress info on the way.

Similar Threads

  1. Replies: 1
    Last Post: 06-21-2013, 04:09 PM
  2. OK, It's Not Really a Bicycle...
    By mtbxplorer in forum Commuting
    Replies: 10
    Last Post: 05-24-2013, 06:25 AM
  3. New Bicycle
    By MarcusSommers in forum North & South Carolina
    Replies: 0
    Last Post: 01-29-2013, 06:12 PM
  4. Zen Bicycle Fab???
    By TIMBERRR in forum Turner
    Replies: 1
    Last Post: 01-18-2012, 06:42 AM
  5. My Bicycle Art.
    By rideit in forum Passion
    Replies: 46
    Last Post: 08-08-2011, 11:23 AM

Posting Permissions

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