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  1. #1
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    Confused about sizing.

    Las week, I was sized at a local LBS, and was told that a 21" frame was for me. I am 6'-2" with a long torso, and "short" legs. ( I am also way overwieght)

    The bike felt fine, but when I straddled the frame, it did "touch". When I rode the bike after adjusting seat hieght, and handlebars, it felt good to me.
    I havent been on a bike for 40+ years, so Im not real sure HOW it should feel to me so I pretty much trusted the sales person.

    Today, I had a "confrontation" with that shop ( a story for another post) and decided to visit the other LBS in town.

    2 Different sales guys fitted me with 19" frames!!!!
    I mentioned that I had been fitted with a 21" frame at another shop.

    They stood by thier assesment.

    So......now I am wondering.................

    1) does frame size REALLY matter ? Once seat hieght and handlebar hieght are set, what difference does frame size matter?

    2) Do the sales people tend to simply fit you to what is on the floor?

    3) In both shops, the employees are YOUNG people. I wonder just how much they really know about sizing.

    I would like to hear some opinions from you guys on how important frame size is.
    It was quite a bit easier to mount the smaller frame, but the bike felt the same to me one seat and handlebars were set?

    puzzles me.....


    phil

  2. #2
    Senior Member late's Avatar
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    1) Fit is the single most important thing to get right
    2) Yes. But there are also differing ideas as to what is a good fit.
    3) I also have a problem with short legs. My feeling is that you should worry less about how the bike is standing still (ie, straddling) and more about how it feels when you are riding it. I suspect you will want the larger frame.
    4)What bikes were you looking at?

  3. #3
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    Exactly. If your seat and bars are in the right place relative to the pedals, what's happening between these points is not very important. Many long time knowledgeable bikers have trouble w this, not just pimpley shop kids.

    Get the smaller frame if the saddle can be set "too high" ie. higher than you now think feels right, as you get more experienced in riding you probably will be comfortable on a saddle that seemed too high at first.

    The main problem w undersized frame especially w less experienced riders is getting the handlebar high enough. Remember, if you decide to raise the saddle, the handlebar is going to become lower relative to the saddle.

    19in is small for 6ft2in rider usually, standover height is less important than how if fits when your riding. Maybe get a 20-21 with sloping top tube so you can stand over the bike while waiting for light to change, etc. A 21in frame with sloping top tube usually has a 19in seat tube. The nominal size based on level top tube bike for comparison purposes. In other words, the top tube is lower but the size is still "21" because if the top tube was level to the ground, the frame would in fact measure at 21in.

    Short version, if your legs are near full extended at bottom of pedal stroke and hbars about the same height as the saddle or higher, lower per your preference then the bike fits.
    Last edited by qmsdc15; 09-04-04 at 01:57 PM.

  4. #4
    Humvee of bikes =Worksman Nightshade's Avatar
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    Yes mate, frame "size" if VERY important for saftey, for
    comfort , for ease of riding, for control of the bike.

    Correct sizing is roughly based on your inseam length.
    Measure your inseam in your underwear to get your true inseam
    then subtract a bit if you wear jeans riding. This number
    will be the safe size to buy so you don't get tangled on &
    off the bike in jeans as opposed to shorts.

    To find the correct bike size measure from the center of the
    pedal crank to the top of the seat post tube. This number is
    the bikes frame size. Match as close as you can to YOUR
    personal inseam measument to find a bike that will be your
    correct size. This can be plus or minus a bit but not much.
    Try to match within one inch. Check this measurement by
    the "stand over" height while stradaling the top bar. You
    want three fingers between your goodies and the top bar in
    jeans for a good frame fit. If it's close you can get by
    with two fingers just don't "rest" on the bar with zero finger
    space!!!

    Adjust your seat so that your knees are slightly bent at the
    bottom of each pedal stroke & your feet can reach the ground
    safely (you might not be quite flat footed but if your knees
    bend a little pedaling you're ok. Just don't be tippy toe.)

    Now go for a ride noting ALL the hand,seat, and pedal positions
    that you find not quite right. Bars & stems can be changed or
    adjuted to you body as can the seat but the frame can't so
    get it right first. Oh yes, Start this process with the
    seat all the way down so as not to confuse the frame issue.
    Last edited by Nightshade; 09-04-04 at 02:09 PM.

  5. #5
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    Subtract 12inches from inseam length as a rule of thumb. don't buy a 31in frame! Don't buy a frame that you can comfortably ride w seat all the way down!

  6. #6
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    and don't ride in jeans, mate!

  7. #7
    Chi
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    Quote Originally Posted by qmsdc15
    and don't ride in jeans, mate!

  8. #8
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    1) does frame size REALLY matter ? Once seat hieght and handlebar hieght are set, what difference does frame size matter?

    Yes it matters. Why? YOu can end up with a top tube that starts to bisect you. Also you can always raise the seat and bars but this leads to back trouble etc.

    2) Do the sales people tend to simply fit you to what is on the floor? In some cases, yes.
    3) In both shops, the employees are YOUNG people. I wonder just how much they really know about sizing.

    That is hard to say

    I am 6'2" w/ 34" inseam. I ride a 19.5". You don't say what type of bike you were being measured for but i will assume a Mountain Bike. I doubt if you will go too wrong with either bike unless your legs are really short or if your crotch is really on the top tube.

    That is a bad deal if you are talking about a Mountain Bike.

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