Can a tall guy ride small?

Discussion in 'Mountain Bikes' started by Piccolo, Dec 26, 2008.

  1. Piccolo

    Piccolo New Member

    May 26, 2005
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    I'm in the market to buy a FS mountain bike. Recently a friend of mine offered to sell me his 2007 Stumpjumper Pro for what I believe is a screaming good deal. Only problem is he is a bit shorter than me and I'm afraid the frame will be too small. I remain optimistic though. Here is a little about myself:

    I used to compute these measurements.
    My measurements:
    Height: 76.00in (6'4")
    Sternum Notch: 62.75in
    Inseam Length: 36.5in
    Arm length: 26.25in
    WS Recommended Sizes:
    Frame Size c-c: 20in
    Frame Size c-t: 21in
    Overall Reach: 70.68cm
    Saddle Height: 81.86cm

    Here's a little about the bike i want to buy. It's a large.
    The geometry of the 2007 Stumpjumper Pro can be viewed here:

    I'm a tall guy (6'4"). I have very long legs (36.5in inseem), however, I have a short torso relative to my height and my neck is really long compared to others. Based on what I can see in the geometry and considering my overall reach(70cm) I have the right torso to fit the cockpit of a Large Stumpjumper but my legs are a bit too long.

    1. I've been told to ride the smallest frame that I can get away with because this lends to greater maneuverability. On the downside it makes going downhill more perilous because I'll be sitting higher up on the bike. Is this true?

    2. Can I raise the seatpost length and handlebar height? Will this have any sort of negative effect?

    3. I've gone on a few test-rides with this bike and haven't felt any major aches or pains afterward. Climbing STEEP terrain was difficult and I fell over the handlebars once on a downhill section. I chalk this up to having no experience though.

    4. Am I rationalizing? [​IMG]

  2. alfeng

    alfeng Well-Known Member

    Jul 23, 2005
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    I don't know if you are rationalizing, or not ... and, I'm not sure what the Wrench Science recommendations actually mean ... but, if the cockpit on a "large" frame fits you, then that is how I would size the frame.

    If the WS 'reach' is the distance between the seatpost & handlebars, then you are well within the correct size with the "large" Specialized frame whose top tube (virtual) is 60cm ... add a ~10cm stem (without taking into account the ACTUAL variation that may result from the offset of the seatpost), and you're good to go. The x-large Specialized frame is shipped with a 120mm stem + the 20mm additional top tube length, so (by theoretical comparison if you were getting the same bike in an XL from a shop), the off-the-peg reach would be 40mm (~1.5") longer ...

    You will not be sitting any higher on a large or x-large frame since the bottom bracket heights are the same on the two frame sizes for that particular frame model ...

    BUT, the x-large frame's heatube is 30mm longer (just over an inch) ... that is-and-isn't a lot ... it depends how many spacers are currently on the steerer -- compare the difference in height of the grips to the saddle (adjusted for you) with the current difference in height with the grips & saddle on your current bike [I'm presuming you currently have a MTB]. Who knows? You may prefer the lower bar position OR you may eventually decide that you need to buy a handlebar (or, stem) with more rise ... and, in the case of the stem, one with more-or-less length.

    FWIW. By my reckoning, and I could have made an error in calculation, a person with almost a 40 inch inseam could adjust the HEIGHT of the saddle with a 400mm seatpost (the standard length which Specialized ships the frame with) on a 'Large' frame without any problem ... figure, 300mm of maximum useable seatpost + 483mm of seat tube lenght + 50.8mm for the saddle + 175mm for the crank arm == more than 1000mm (39").

    Regardless of whether the frame with its 400mm seatpost is long enough, I think you should probably install a set of 180mm cranks (or, longer ... ZINN has longer cranks ... but, they are REALLY EXPENSIVE) at some point.

    I'm not sure what the bike listed for OR what you consider to be a 'screaming good deal' ... but, if a 2007 NOS bike were available from a shop then it should sell for only about 65% (or, less because the bike is theoretically 2 years old) of the original, suggested retail price ... if the bike listed at $2400 (for example -- I am clueless as to how much that bike originally retailed for), and is in close-to GREAT cosmetic condition (frame, crank, derailleurs) & he is offering to sell it to you for $1000, then I'd agree it is a 'screaming good deal' ... $1200 may still be a really good deal ... but, not necessarily a 'screaming good deal' ... if he wants more (again, presuming it listed at around $2400 ... adjust dollar amounts, accordingly), then either haggle with him OR look on-line.

    IMO, a reason I would shy away from the Specialized (and, this may be a really poor reason ... and, I am NOT the arbiter of what is the best suspension design) is because I'm not sure that it is the best rear suspension design ... or, even one of the better designs.

    Another reason is because at your height, you should possibly be looking at a 29er ... maybe, not.

    Finally, despite what I've just said, if YOU think it is a 'screaming good deal' regardless of how much your friend is asking, then I would say that the frame WILL definitely fit you & you should give serious consideration to buying it AFTER you ask him what he is replacing it with & why.
  3. K50

    K50 New Member

    Oct 7, 2005
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    regardless of how tall or short one is, my advice is to never ride 'small'. Buy the frame that fits the best. If you'd like to ride 'small', you may be able to ride a frame that feels slightly smaller, like the difference between a road frame and a cyclocross frame, but never go overboard and try to compensate by using a huge seatpost and stem length. The frame itself should still be within the right range based on your height/measurements. Using myself as an example, I struggle with mountain bike frame sizes because often I'm too short to be tall, and too tall to be short, and my ideal frame size is a ML. This doesn't work well with most manufacturers as most offer a medium or a large, but not a medium large like some of the more large-scale companies offer. When it comes to deciding which one to go for, the last couple years I've been opting for the larger size frame. When I first got into competetive cycling, I used the smaller size frame because it IS a lot more maneuverable and lighter and easier to handle and faster through switchbacks, but it ended up being uncomfortable in the long run and I struggled a lot with lengthening the cockpit and attaining a proper 50/50 weight balance. The larger frame ended up being a much wiser choice. It gave me more options, more room to move around and it actually ended up being easier to get proper weight balance for climbing and descending. I didn't feel squished and never suffered any discomfort from having my seat too far forward or back like I did on the old medium size frame I rode before. To give you an idea, the difference in TTT of the two bikes was a 595mm vs a 585mm. The 595mm fit much better, even though theoretically I could have ridden either one. My seat height stayed the same on both bikes, but on the larger frame because I was more stretched out it allowed me to lower the handlebars a bit if I wanted, which I couldn't do on the smaller frame because it would have been too cramped. Hope this helps if you're still kicking around.
  4. peet9471

    peet9471 New Member

    Dec 11, 2004
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    Look at distance between your knees and the stem. Larger bikes have a longer top tube. I like to be stretched out rather than cramped up in a ball. Most bikes today don't have a problem with stand over clearence since the top tube is slanted.