Results 1 to 24 of 24

Thread: Frame size

  1. #1
    mtbr member
    Reputation:
    Join Date
    Nov 2013
    Posts
    8

    Idea! Frame size

    Hi dear

    i am from Cambodia , nice to be part of mtbr forum . Today I have a doubt and hope everyone could help .

    I am 172cm , inside leg is 78cm
    My bike is scott scale 20 , frame size 400mm ( s ) .
    Is it too small ? Or is it just small but usable ?

    Thanks for information in advanced .

  2. #2
    Sergeant Spandex
    Reputation: lewisfoto's Avatar
    Join Date
    Nov 2013
    Posts
    550
    If I am doing the math correctly then this bike should be good for you.

  3. #3
    mtbr member
    Reputation:
    Join Date
    Apr 2011
    Posts
    2,094
    So 5.5 ft tall and riding a small? Sounds right.

  4. #4
    mtbr member
    Reputation:
    Join Date
    Oct 2013
    Posts
    41
    5'7"

  5. #5
    mtbr member
    Reputation:
    Join Date
    Apr 2011
    Posts
    2,094
    Quote Originally Posted by Coverdog View Post
    5'7"
    5.5 ft is approx. 5' 7".

  6. #6
    mtbr member
    Reputation:
    Join Date
    Nov 2013
    Posts
    8
    Quote Originally Posted by phsycle View Post
    So 5.5 ft tall and riding a small? Sounds right.
    So the right size is little bigger ? Or I could still use my current MTB ?

    Thanks

  7. #7
    mtbr member
    Reputation:
    Join Date
    Nov 2013
    Posts
    8
    Quote Originally Posted by lewisfoto View Post
    If I am doing the math correctly then this bike should be good for you.
    But I have to up the seat posts to hight , right ?

  8. #8
    Sergeant Spandex
    Reputation: lewisfoto's Avatar
    Join Date
    Nov 2013
    Posts
    550
    Quote Originally Posted by Reaksmeybora View Post
    But I have to up the seat posts to hight , right ?
    Maybe a quick pic of your set up would help

  9. #9
    mtbr member
    Reputation:
    Join Date
    Nov 2013
    Posts
    8
    This is picture of MTB
    Attached Thumbnails Attached Thumbnails Frame size-image.jpg  

    Attached Images Attached Images  
    Last edited by Reaksmeybora; 11-21-2013 at 03:35 PM.

  10. #10
    Sergeant Spandex
    Reputation: lewisfoto's Avatar
    Join Date
    Nov 2013
    Posts
    550
    That frame looks smaller than you originally posted, 400mm equals about 15.75 inches, that looks like a 13inch frame to me. However based on the picture alone I would say you need a bigger frame.

  11. #11
    mtbr member
    Reputation:
    Join Date
    Nov 2013
    Posts
    8
    This is 400mm as shown on frame

  12. #12
    Sergeant Spandex
    Reputation: lewisfoto's Avatar
    Join Date
    Nov 2013
    Posts
    550
    Quote Originally Posted by Reaksmeybora View Post
    This is 400mm as shown on frame
    Ok fine, but based on how much seat post you have showing you will need a bigger bike.

  13. #13
    mtbr member
    Reputation:
    Join Date
    Oct 2013
    Posts
    41
    Quote Originally Posted by phsycle View Post
    5.5 ft is approx. 5' 7".
    I guess if you don't count the other inch

  14. #14
    Happy Trails
    Reputation: Scott In MD's Avatar
    Join Date
    Sep 2008
    Posts
    947

    Frame size

    I'm not a bike fitter but maybe this helps: A reasonable thumb rule is that the distance from center of bottom bracket (also the center of crank) to top of your saddle should be 85% of your cycling inseam. Cycling inseam is defined as the distance from floor to your crotch, measure up up snug like a bike saddle would sit. Cycling inseam is not the inseam of your jeans .... It is a little longer.) If your saddle is set to the correct height, then your bike could be a little small, but could be fine and is certainly rideable. Many people, including me, prefer a smaller bike versus a larger bike since it is more agile and lighter. Many amateur riders like me, also prefer their handlebar grips adjusted to level with or slightly above saddle height (flat level to about 25mm higher) so you may want to swap your flat bar for a riser bar to raise your handlebars up a little, or else use a different stem to raise your bars a little. I would not be worried about the size as set up in that photo, however, as long as your saddle is raised to the correct level. It would be easier for us to give you some better advice if you could snap a photo of you on the bike, but my bike is set up similar to yours, only I have even more seat post showing than you, and I also have riser bars to raise my grips about 20mm above saddle.

  15. #15
    Happy Trails
    Reputation: Scott In MD's Avatar
    Join Date
    Sep 2008
    Posts
    947

    Frame size

    Quote Originally Posted by lewisfoto View Post
    Ok fine, but based on how much seat post you have showing you will need a bigger bike.
    I think this not a valid comment. As long as the seat post is below the minimum insertion point, the seat post is fine, and the bike, set up exactly like this, would fit riders of a certain size. Lots of riders ride hard tails set up EXACTLY like this, with bars slightly lower than saddle top to get a good balanced position. I need my bars a little higher ... But this is right where a lot of flexible riders like to be. Happy trails.
    Last edited by Scott In MD; 11-23-2013 at 05:25 AM.

  16. #16
    mtbr member
    Reputation:
    Join Date
    Nov 2013
    Posts
    8
    Quote Originally Posted by Scott In MD View Post
    I'm not a bike fitter but maybe this helps: A reasonable thumb rule is that the distance from center of bottom bracket (also the center of crank) to top of your saddle should be 85% of your cycling inseam. Cycling inseam is defined as the distance from floor to your crotch, measure up up snug like a bike saddle would sit. Cycling inseam is not the inseam of your jeans .... It is a little longer.) If your saddle is set to the correct height, then your bike could be a little small, but could be fine and is certainly rideable. Many people, including me, prefer a smaller bike versus a larger bike since it is more agile and lighter. Many amateur riders like me, also prefer their handlebar grips adjusted to level with or slightly above saddle height (flat level to about 25mm higher) so you may want to swap your flat bar for a riser bar to raise your handlebars up a little, or else use a different stem to raise your bars a little. I would not be worried about the size as set up in that photo, however, as long as your saddle is raised to the correct level. It would be easier for us to give you some better advice if you could snap a photo of you on the bike, but my bike is set up similar to yours, only I have even more seat post showing than you, and I also have riser bars to raise my grips about 20mm above saddle.
    Thanks you very much for sharing .......

  17. #17
    It's about showing up.
    Reputation: Berkeley Mike's Avatar
    Join Date
    Jan 2004
    Posts
    11,277
    You are fine. The "how much seat post is showing", especially considering the way the top tube slopes down, doesn't apply here.
    Attached Thumbnails Attached Thumbnails Frame size-bontia.jpg  

    I don't rattle.

  18. #18
    mtbr member
    Reputation:
    Join Date
    Nov 2013
    Posts
    8
    Quote Originally Posted by Berkeley Mike View Post
    You are fine. The "how much seat post is showing", especially considering the way the top tube slopes down, doesn't apply here.
    Thanks you sir,
    The seat post is longer , ( as shown in picture , )
    So I could up the seat post as long , By No need to change to the bigger Fram ?
    Attached Thumbnails Attached Thumbnails Frame size-image.jpg  

    Frame size-image.jpg  


  19. #19
    Sergeant Spandex
    Reputation: lewisfoto's Avatar
    Join Date
    Nov 2013
    Posts
    550
    Quote Originally Posted by Berkeley Mike View Post
    You are fine. The "how much seat post is showing", especially considering the way the top tube slopes down, doesn't apply here.
    Maybe but a long seatpost works as a lever so having a lot of post out will increase lateral stress which can lead to frame failure at the top of the seat tube particularly if there is only a few inches of post in the frame.

  20. #20
    Happy Trails
    Reputation: Scott In MD's Avatar
    Join Date
    Sep 2008
    Posts
    947

    Frame size

    Quote Originally Posted by lewisfoto View Post
    Maybe but a long seatpost works as a lever so having a lot of post out will increase lateral stress which can lead to frame failure at the top of the seat tube particularly if there is only a few inches of post in the frame.
    Lewis - I edited my earlier reply to your post above ... At first I said your comment was stupid, but I changed it to "not valid" to give you benefit of doubt. That was a mistake ... Your comment was stupid, but this comment is almost as stupid. Actually, it's a toss-up which is more stupid.

    As long as the post is inserted past the minimum insertion line marked on the post about four inches from the bottom, the stress on the post and bike will be fine. OP is not going to crack his aluminum bike, and seat posts have massive design margin against failure. I realize you are trying to be helpful, but keep your day job, bro. If you don't believe me, ask Jaroslav....



  21. #21
    Sergeant Spandex
    Reputation: lewisfoto's Avatar
    Join Date
    Nov 2013
    Posts
    550
    You make a valid point about the minimum insertion line but by calling me, or anybody, "stupid" then you just make yourself look stupid. Long posts cause stress at the top of the seat tube, that is not opinion it's physics. In some causes this will cause frame failure.

  22. #22
    Happy Trails
    Reputation: Scott In MD's Avatar
    Join Date
    Sep 2008
    Posts
    947

    Frame size

    Lewis, peace. (Besides I didn't call you stupid. I called your post stupid.)



  23. #23
    Sergeant Spandex
    Reputation: lewisfoto's Avatar
    Join Date
    Nov 2013
    Posts
    550
    Quote Originally Posted by Scott In MD View Post
    Lewis, peace. (Besides I didn't call you stupid. I called your post stupid.)



    That is one of the most gracious things I have read on any forum in a while, so peace to you too and have a good night.

  24. #24
    Happy Trails
    Reputation: Scott In MD's Avatar
    Join Date
    Sep 2008
    Posts
    947
    Posrep fo' you, bro. See you out there. (Karma's probably gonna crack my post this weekend….)

Similar Threads

  1. Broke my frame today, new bike or frame? What size?
    By JFD27 in forum Bike and Frame discussion
    Replies: 3
    Last Post: 11-08-2013, 10:05 AM
  2. Replies: 0
    Last Post: 03-06-2013, 02:22 PM
  3. wheel size and frame size
    By tosa in forum 29er Bikes
    Replies: 2
    Last Post: 01-19-2013, 03:23 PM
  4. Replies: 5
    Last Post: 09-08-2012, 07:40 AM
  5. Wheel size follows frame size
    By JonathanGennick in forum 29er Bikes
    Replies: 12
    Last Post: 09-09-2011, 02:40 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
  •