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Thread: Bike Size

  1. #1
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    Bike Size

    I am 5'7" tall and 29-30" inseam.
    I always marvel at the length of the exposed seat post on bikes that gives people room to put a tent/sleeping bag/pad on the rack.
    Somehow, I am unable to handle the elongated seat post.

    I have a MTB with 18" frame and a Trek 700 with 21" frame and 700c wheels, that I am equipping as a touring bike.
    The stand over height is OK.
    May be I could pull out the seat post but then I will not be able to touch the ground with my toes when standing still.
    I don't think I can use something like this http://www.wiggle.com/carradice-bagm...ort-bag-mount/with the seat post just 1-2" out.

    Am I using bikes too large for my height or am I incorrect in keeping the seat post exposed only 1-2"?

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    Quote Originally Posted by ak08820 View Post
    I am 5'7" tall and 29-30" inseam.
    I always marvel at the length of the exposed seat post on bikes that gives people room to put a tent/sleeping bag/pad on the rack.
    I'm 5'9 with a 32" inseam. I use a Carradice Nelson Longflap bag and Bagman support and don't have a ton of clearance between the bag and the rear tire; if I hit a big bump or pothole I occasionally feel the bag make contact with the rear tire.

    May be I could pull out the seat post but then I will not be able to touch the ground with my toes when standing still.
    The seat post should be in a position that gives you proper leg extension when pedaling. If you're sitting on the saddle and you're able to put your fee on the ground, your saddle is likely way too low!

    Am I using bikes too large for my height or am I incorrect in keeping the seat post exposed only 1-2"?
    A smaller frame will require more seat post extension in order to put the saddle at the correct height. At the same time, the top tube will be shorter which will lead to a more upright seating position... but there's only so far you can go: at some point the top tube will get short enough that you'll start to feel too cramped on the bike.

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    Quote Originally Posted by sstorkel View Post
    The seat post should be in a position that gives you proper leg extension when pedaling. If you're sitting on the saddle and you're able to put your fee on the ground, your saddle is likely way too low!
    +1.

    OP: Get fit at a shop.

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    ak-

    I'm about your size, 5' 6.5", with a 31" inseam to ground. After confirming your optimum saddle/pedal distance as suggested above consider a frame with a more steeply sloped top tube. I used to ride a conventional touring bike with a level top tube. It was close to your Trek at 20.5" (52 cm). That resulted in about 2-3" of exposed seat post. I also felt too close to the top tube. I now ride a Bruce Gordon Rock'n Road with a steeply sloped top tube. It's seat tube is about 16" (41 cm) and I have 6"+ of exposed seat post. That's much better crotch and luggage clearance. If I hold a level from head tube back to seat post it shows that I'm riding the equivalent of the 20.5" frame that I used too.

    All measurements above are center to center. My toes are maybe 1-2" off the ground straddling the saddle. Happy Holidays!

    edit#2- I've retracted part of this post at my post #10 below
    Last edited by BobG; 12-29-13 at 06:46 AM. Reason: number corrections

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    coprolite fietsbob's Avatar
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    Stand over the top tube, ahead of the saddle. flat footed, how much clearance is there?

    The stand over height is OK.
    ,,

    just no idea what OK is translated in terms of inches or centimeters .

    so can't say without being there.. which I'm Not.

    +1, go consult at a Bike Shop , where they can See you ..
    Last edited by fietsbob; 12-25-13 at 11:31 AM.

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    I agree with the person who said if your feet reach the ground while sitting on your bike's saddle, it's too low.

    Set your saddle at a height that requires a slight stretch in your ankle/foot to pedal and/or causes you to rock back and forth while pedaling because it's so high. Have a friend watch you from behind as you pedal. Lower the saddle in as small increments as you can manage....a few mm only.....and have the friend watch you again. Keep repeating and when you are no longer rocking back and forth and there is only a very slight bend in your knee when the pedal is at the bottom position with the ball of your foot on it....the saddle height is correct or very close to it. You'll also experience a LOT more power to the pedals for your efforts.

    You also need to get the front-back dimension for the saddle on the rails dialed in where it's most comfortable for how you pedal. Then you can start thinking about stems and reach to the handlebar. You may find that neither bike is the right size for you and it might be N+ 1 time. That's where I'm at right now.

    I'm 5'11" with a PBH (inseam measured to pubic bone) of about 33.5" and I have a 21" Trek 730 and I have a LOT of seatpost showing......probably 8-10 inches from the top of the seat tube to the clamp, then add the height of the clamp and the saddle. It's actually a too small frame for me.

    Here's a photo of my 21" Trek 730 with the saddle at the correct height.

    IMG_1114_zps8b772a9d.jpg
    Last edited by corwin1968; 12-25-13 at 12:08 PM.
    Currently riding a 2013 Handsome Devil custom build and an 80's Takara Highlander (MTB built in the style of an 82-84 Stumpjumper).

  7. #7
    coprolite fietsbob's Avatar
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    when its right , I can look straight thru the steering axis of the fork.
    [in the position i use most on that bike ]


    +x The saddle height is in relation to leg extension pedaling the bike, not stopping.



    if you really need the flat footed stop to feel secure .

    get a crank-forward frame bike, or a recumbent.
    Last edited by fietsbob; 12-25-13 at 12:59 PM.

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    Quote Originally Posted by ak08820 View Post
    I
    May be I could pull out the seat post but then I will not be able to touch the ground with my toes when standing still."?
    When you are standing still there is no need to have both feet on the pedals and butt on the saddle. So set the seat height for pedaling and get off the saddle when you need to stand.

  9. #9
    Senior Member Jim Kukula's Avatar
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    I'm pretty comfortable set up like this:


  10. #10
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    Quote Originally Posted by BobG View Post
    After confirming your optimum saddle/pedal distance as suggested above consider a frame with a more steeply sloped top tube.
    Correction. Now that I think about it, I'm wrong here. A rack is attached to seat stays at a prescribed height above the wheel. Saddle-pedal distance is constant regardless of frame design. A frame with a sloped top tube simply has it's rack attached higher on its shorter seat stays but at the same height above the wheel as one with a level TT. A sloped TT will definitely provide more standover height but will not give more baggage room in the rear.

    The same holds true for a seat mounted bag or rack as the OP is interested in. The saddle and wheel/fender heights are pre-determined. The space between the two will be the same with whatever seat tube/seat post combination is chosen.

    We short guys just have to ride closer to the rear wheel than the tall guys do.
    Last edited by BobG; 12-29-13 at 06:44 AM.

  11. #11
    coprolite fietsbob's Avatar
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    I have room for more stuff within the main triangle if it does not slope so much..

    2 bottles over 1 under the down tube, and another on the seat tube, a long frame fit pump,
    and a coiled up lock ..
    It: [Specialized sold a Kevlar cable lock with steel segmented armor sleeves,over the cable ]

    it rolled up to hang in the space above the bottles , under the down tube, nicely ..
    Last edited by fietsbob; 12-26-13 at 01:54 PM.

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    I rode bike too big for me for about a year (a hybrid). I had about an inch clearance between the saddle and the rack. I had to move the saddle forward because of the length between seat post and handle bars. I used to have to lean the bike to one side to place my foot flat on the ground; and this was off the saddle. I felt that I rode it well enough, as long as I had the saddle to peddle set right for my leg length. My opinion is that riding a bike to big may take getting used to but once you adjust it to your comfort and get used to the little things like leaning to the side at stop lights, you can successfully ride it without too many problems. There could be some safety concerns about riding a large bike: emergency stops and the such. I never experienced knee, leg, or back pain riding in the year I used it to ride to work, about twice a week, 13 miles each way.

  13. #13
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    What the OP is thinking of is a 26" wheel bike like Jim K's. They are often touted for tour bikes anyway.
    The solution is N-1+1.

  14. #14
    coprolite fietsbob's Avatar
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    FWIW my Koga WTR is also a 26" wheel , R is for Rohloff, WT is for World Tour, which many owners have done with theirs .

    Happens to have a level top tube.. It's A NL company, where as Thorn is a UK company ..

    the one I mentioned above (with 700c wheels) above has some top tube slope..

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