Frame sizing question...

Discussion in 'Bike buying advice' started by thegnome, Mar 21, 2011.

  1. thegnome

    thegnome New Member

    Joined:
    Mar 21, 2011
    Messages:
    4
    Likes Received:
    1
    So I bought a Giant Defy in size M, and I think It's too big (lbs sizing was just standover, and it seemed right from a background with traditional frames, but now I'm starting to feel as though it's too long), so I'm considering selling it and buying a different bike.

    I am 5'6" with a 30" cycling inseam... should I have gone with a S? XS? and should I go through the trouble of buying a new bike, or should I just get this one more fitted to my physique?
     
    Tags:
    Pax likes this.


  2. alfeng

    alfeng Well-Known Member

    Joined:
    Jul 23, 2005
    Messages:
    6,723
    Likes Received:
    126
    FWIW. With the understanding that you may be more flexible than I am, or vice versa, I would guess that a person (e.g., YOU) who is 5'6" tall would want a frame with a combined top tube (real or virtual) + stem length of about 63cm ... I'm 5'9" tall & I am basing that 63cm dimension on MY frame & stem whose combined length equals 66cm.

    Handlebar reach AND seatpost setback need to be factored in, too; but, use that 63cm dimension as a starting point WITH a normal seatpost which has more than a zero setback ...

    • So, presuming that the virtual top tube on your current frame is about 54cm-to-55cm, then you'll probably want an 80mm or 90mm stem as a starting point to adjust your current bike so that it fits you better ...

    Most shops will exchange some components like stems during the first two-or-three months to ensure that what they sell you fits ... if not, then you'll have to buy a stem off of eBay (why pay more?) and you'll know that any future purchases of more than a few dollars should be spent at a different bike shop OR online.
     
  3. thegnome

    thegnome New Member

    Joined:
    Mar 21, 2011
    Messages:
    4
    Likes Received:
    1
    I understand that fit can be adjusted with seatpost and handlebar stem replacement. My question is, would that be a better use of resources than just buying a new bike (assuming cost isn't a factor)? If the frame is in-fact the wrong size, and I'm not just being overly cautious, would it be "better" to get a different frame that fits better as stock and then fine-tune as opposed to changing components on the current frame?
     
  4. swampy1970

    swampy1970 Well-Known Member

    Joined:
    Feb 3, 2008
    Messages:
    10,057
    Likes Received:
    185
    Is it a case where it really is the wrong size or is it actually the right size but you're just that you're not used to it?

    A picture is worth a thousand words...
    ... or something like that.
     
  5. thegnome

    thegnome New Member

    Joined:
    Mar 21, 2011
    Messages:
    4
    Likes Received:
    1
    Tried posting pics, but I got a notice about my post requiring moderation... and it hasn't posted yet.
     
  6. DAL1955

    DAL1955 New Member

    Joined:
    Jan 20, 2011
    Messages:
    115
    Likes Received:
    4
    Given you user name and the 30" inseam at 5'6", I'm assuming that you are what would be called short waisted. Basically you have a short torso. So also assuming that you don't have exceptionally long arms, you probably are reaching a bit, but probably not overly so, on the medium with the standard 100mm stem. I have the Defy Advanced in the same size, but I am 5'10 and have the same 30" inseam and am somewhat longer in the torso. Before you scrap the bike you have and move on, I would get properly fitted on your bike by someone who knows what they are doing. Between a shorter stem, and moving the saddle forward a little you will very likely find the sweet spot that fits you. Also, I would ride it for 30-60 days and then go to a fitter and tell him what you find uncomfortable and go from there. The Defy line is a nice comfortable bike when fitted properly. Give a good shop the chance before you move on.

    DAL
     
  7. davereo

    davereo Well-Known Member

    Joined:
    Jun 17, 2010
    Messages:
    1,639
    Likes Received:
    70
    Are you sure you have a 30" inseam? If you are wearing a 30 X 30 pair of Levi's your inseam for cycling purpose's is around 34'. Just Saying.
     
  8. davereo

    davereo Well-Known Member

    Joined:
    Jun 17, 2010
    Messages:
    1,639
    Likes Received:
    70
    I ride Cannondale bikes and comfortably fit 56 and 54 CM models. On the 56's I change out the stem to 90CM and my reach is perfect. With that said I would follow Alfengs advice and try swapping the stem. Very easy to do and a hell of a lot cheaper than getting another bike.
     
  9. davereo

    davereo Well-Known Member

    Joined:
    Jun 17, 2010
    Messages:
    1,639
    Likes Received:
    70
    I just checked your profile and you have two pics in your default album. I looked at your pics and think that your bike size is fine. As you get in better shape you will be more flexible. You look like you are trying to hold yourself up. As your trunk becomes a little stronger you will be able to lower yourself into your bike in a more areo position.
     
  10. thegnome

    thegnome New Member

    Joined:
    Mar 21, 2011
    Messages:
    4
    Likes Received:
    1



    Not consciously holding myself upright, just have to extend the arms fully to reach the hoods without leaning forward quite a bit, and my understanding is that the hoods should leave your trunk at ~45 degrees. I could use more development in my core muscles, but I'm not feeling difficulty in maintaining position without aid of my arms.

    I do plan to get a scheduled fitting session in, I just don't want to start off wearing dad's pants and trying to get the tailor to hem them for me, when a new pair would be a better choice (if slightly more expensive).
     
  11. davereo

    davereo Well-Known Member

    Joined:
    Jun 17, 2010
    Messages:
    1,639
    Likes Received:
    70
    I like the analogy of the Tailor. Like buying a new suit all the sizes on the rack are rough. They dont fit well until a Tailor custom fits them.
    Same thing goes when buying a new bike. Follow through on that fitting you will be very happy with the end result.
     
  12. DAL1955

    DAL1955 New Member

    Joined:
    Jan 20, 2011
    Messages:
    115
    Likes Received:
    4
    You're probably right, I didn't pickup the cycling part of the inseam in the original post. My Giant Defy measures exactly 30" from floor to top tube and when I stand over the top tube, it just brushes the twins. My MTN bike is larger, measures 33" floor to top tube and I can still stand over it, though somewhat more carefully./img/vbsmilies/smilies/smile.gif Looking as you did at his profile pics, I too think he is on the right size bike, and his issues are fitting related not frame size related IMO.
     
Loading...
Loading...