1. The most important thing about buying a new bike is to make sure it fits. The only way you'll know if the bike is right for you is to size up the bike and make sure that the bike's geometry matches your body's geometry. Ask questions and do some research.
mtn. biking 101
2. If possible, try to find a shop that will let you demo the bike on real dirt. Five minutes in a parking lot won't cut it. You wouldn't buy a car without a real world test drive, and a bike should be no different.
3. Don't belive the hype. Just because your favorite rider or best friend rides a certain bike, that doesn't mean that's the best one for you. Have an open mind and be realistic about your needs and ability.
Results 1 to 17 of 17
  1. #1
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    How do I determine bike size for me: 6"2, 36.5 inseam.....21" or 23" frame size?

    I have a huge dilemma determining the size of my bike and though I'd look here for expert's advice (the bike store's staff, basically didn't advise me anything but "what feels better")

    I have my eye on "Specialized Stumpjumper 29'er" 2011

    Here are my specs: I am 6"2 tall, and my inseam is 36.5"
    In the past I rode 22" low end (cheap) bike and was happy with it except one issue: I could never lift seat high enough to feel comfortable. Otherwise the bike was OK.

    Now I am on the verge of a big investment and I found following:
    23" bike (see link above) feels comfortable regarding seat size and armlength BUT the only problem is when I barefoot stand over the middle portion of the tube, the tube just about touches my groin....I've read on few websites that this is NOT supposed to happen.

    I tried today 21" frame bike (Specialized Stumpjumper) 29'er and I found myself again lifting seat to extreme highs just to feel comfortable (and it still wasn't high enough"), the front bar was switched from 110 to 120mm and it felt ok. The bike felt a bit small but good navigation. the middle portion of the top bar was about 2 inches (barefoot) over my groin.

    I am almost sold to go for a larger bike (23") but I saw that almost EVERY website that I visited suggests that if I am in between the sizes, I should size DOWN, rather than up.


    Can anyone provide thoughts on above? Which frame size for my size/height?

  2. #2
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    I am 6'3" and have a 21" 29er, fits me good. Never been on a 23" but I would say whatever feels best for you is what you should get.

  3. #3
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    where are you located?
    '98 GT Backwoods

  4. #4
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    Quote Originally Posted by adrianm1188 View Post
    where are you located?
    Chicago

  5. #5
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    Quote Originally Posted by ccs1676 View Post
    I am 6'3" and have a 21" 29er, fits me good. Never been on a 23" but I would say whatever feels best for you is what you should get.
    I forgot to say it's a MOUNTAIN bike, not a road bike.

    I feel like I have better control on 21"...it feels smaller, but I feel I can maneuver on city streets very well. The 23" feels big, and I it feels as if I didn't have entire control over it.

    I have read that the frame size best for me is 21" based on my height and inseam, and general recommendation is if one is in between frame sizes to go with a smaller frame size , and that if it's a mountain bike (like mine), the top tube should be 3-4 inches above the groin joint point.

  6. #6
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    Quote Originally Posted by ccs1676 View Post
    I am 6'3" and have a 21" 29er, fits me good. Never been on a 23" but I would say whatever feels best for you is what you should get.
    do you have a road bike or mountain bike?

  7. #7
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    Quote Originally Posted by anukto View Post
    do you have a road bike or mountain bike?
    Most likely he's talking about a mtn bike, normally the size on a road bike would be listed in cm instead of inches. One exception would be hybrids, many are listed in inches but they'll list the wheels/tires as 700c instead of 29".

    There isn't really a hard rule to say that if you're "x" tall you need "y" sized bike, The closest you'll get is to find a range of possible bikes to try. I'm just a hair under 6'4" with 34" inseam and fit great on my 19" Hardrock 29er with a 10mm longer stem (100mm) and a low rise (10mm rise, 6 degree sweep) handlebar, if you take into account the difference in top tube length, stem length and handlebar the effective reach would be comparable to a stock 19" Stumpjumper. A 21" Hardrock felt a bit too large for me, the top tube is 30mm longer. I was OK with the reach to the bars but it just felt a bit too large. Going with the 19" but getting my bar a bit lower and 10mm further out feels "just right". I read one thing recently that's very unscientific but can tell you if a bike is likely too small: Sit on the bike in a normal riding position and look down at the handlebar in relation to the front hub. The handlebar should be about 1" in front of the invisible centerline of the hub. If the handlebar is covering up the hub it's too small, if there's a large gap the bike is likely too large. The only real downside I see with this is that there's a lot of margin for error and only works well if a bike is maybe 2 sizes too large or small.

    Even on a properly sized bike it'll look like you have a mile of seat post sticking out since you're long legged, as long as the seatpost is long enough it's a non issue. I think I'm a good 2.5" from getting to the "minimum insertion point" on my stock seatpost so you shouldn't have any issues on a 19" and larger Stumpjumper. With your inseam you'll probably need to be more concerned with proper leg/saddle position rather than the reach to the bars. You may have about 1/4" of safe adjustment with the factory saddle/post so you may still be able to easily choose between 2 different sizes and be close to a perfect fit but it will take a bit of help from the LBS you're looking to buy from. You'll need the saddle set at the correct height for your legs and your kneecap should be above the centerline of the crank while you're at the 3 o'clock position. If you were test riding bikes with the saddle set too low they'll probably feel too small since you're a bit closer to the bars and sitting more upright. If the seat is a few inches too low I could see a 21" feeling as small if not even smaller than a 19" with proper height.

    As for standover, it's nice if you do have a little "breathing" room but it's not the be all end all that some make it out to be. The only time I've ever heard anyone say it's important is when they're a new rider, it's not really very common to straddle the bike with both feet on the ground for most riders. Usually if you come up to a stopping point you'll put one foot down but keep the other on the pedal, if needed you could lean the bike a little to the side to get enough clearance to safely put both feet on the ground.

    If you ask 10 different people you'll likely get 7-8 different opinions on what size you should go with, I think you may be well suited for either a 19" or 21" but would expect the 23" to be too large. The 19 vs 21 would likely be decided by which one goes best with your leg length, you can easily move the bars 20mm or so towards/away from you to suit you.

    Larry

  8. #8
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    I'm 6'3" and ride a 20" (L) mountain bike. But my road bike is a 58 cm (XL). It's all about how you feel on the bike, your best bet would be to go to you LBS and try out a couple different sizes.
    -Nick

  9. #9
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    The sizing method of using the sight line to the front hub and seeing if the bars are in front of or behind the hub is an old way. From what I recall the proper size was if the bars, cover the front hub. Anyway, I've heard its out-dated. The head tube angle, fork length, and wheel size (26 vs 29) would really mess this sizing method up.

    I'm similiar to Larry in that I'm about 6'4" and ride a large. 9 out of 10 would probably say its too small for me. I still have 2+ inches of seat post beyond the minimum mark. Raising the seat post equals a longer reach because the seat goes back a bit as it goes up. I ride with the stock stem of 100mm although I might go longer to a 110 to get more weight on the front wheel for climbing.

    Spend time at your bike shop. What do they recomend? Try a second bike shop just to see what they say for a size. 2 bike shops fit me to a large.

    Get what you like the best and have fun riding.

  10. #10
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    Quote Originally Posted by qa_bugfinder View Post
    The sizing method of using the sight line to the front hub and seeing if the bars are in front of or behind the hub is an old way. From what I recall the proper size was if the bars, cover the front hub. Anyway, I've heard its out-dated. The head tube angle, fork length, and wheel size (26 vs 29) would really mess this sizing method up.
    It sounded like a good idea (although lots of room for interpretation) until I thought about your last sentence and I can see that it's "the old way" for good reasons. Especially if you're looking at the Fisher bikes with the G2 offset.

    One thing worth noting, I know you mentioned the Stumpjumper 29er but don't totally discount other brands while you're looking and don't get too caught up in the actual "size" of the bike. A 21" from one brand might have the same effective top tube length as a 19" from another. The components are very similiar if you're at a comparable pricepoint (as the price goes up there's more variance though) so if you find 2-3 bikes that feel perfect for you won't go wrong with picking your favorite color or buying from the shop with the best service. If from the same shop and you can't pick a favorite I'd probably have to go with a coin toss.

    Larry

  11. #11
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    I'm also 6'4" and 36" pants, I just bought a trek 4300 21" last night, fits me great w/o too much seat height. My last bike was a trek 830 from 10 years ago, lets just say I grew out of the 19.5 frame. I would suggest test driving a couple different sizes from your lbs.

  12. #12
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    It seems to me you don't want anything so high that when you hit a root & you get thrown forward off the saddle your first impact is cross bar to family jewels. For this reason alone, I wouldn't even consider getting a bike that's larger if I'm inbetween sizes, even if it's just a little. You only need an inch or less of standover clearance but I definitely wouldn't want to ride without it. Gotta protect my boys!

  13. #13
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    I'm 6'2" and i ride a 19" specialized Rockhopper and it feels great to me

  14. #14
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    Quote Originally Posted by Nick_Good View Post
    I'm 6'3" and ride a 20" (L) mountain bike. But my road bike is a 58 cm (XL). It's all about how you feel on the bike, your best bet would be to go to you LBS and try out a couple different sizes.
    -Nick
    I'm not surprised. I've heard and read that road bikes should be 2-3 inches larger than mountain bikes. Thanks for sharing your experience!

  15. #15
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    Quote Originally Posted by Larry_K View Post
    Most likely he's talking about a mtn bike, normally the size on a road bike would be listed in cm instead of inches. One exception would be hybrids, many are listed in inches but they'll list the wheels/tires as 700c instead of 29".

    There isn't really a hard rule to say that if you're "x" tall you need "y" sized bike, The closest you'll get is to find a range of possible bikes to try. I'm just a hair under 6'4" with 34" inseam and fit great on my 19" Hardrock 29er with a 10mm longer stem (100mm) and a low rise (10mm rise, 6 degree sweep) handlebar, if you take into account the difference in top tube length, stem length and handlebar the effective reach would be comparable to a stock 19" Stumpjumper. A 21" Hardrock felt a bit too large for me, the top tube is 30mm longer. I was OK with the reach to the bars but it just felt a bit too large. Going with the 19" but getting my bar a bit lower and 10mm further out feels "just right". I read one thing recently that's very unscientific but can tell you if a bike is likely too small: Sit on the bike in a normal riding position and look down at the handlebar in relation to the front hub. The handlebar should be about 1" in front of the invisible centerline of the hub. If the handlebar is covering up the hub it's too small, if there's a large gap the bike is likely too large. The only real downside I see with this is that there's a lot of margin for error and only works well if a bike is maybe 2 sizes too large or small.

    Even on a properly sized bike it'll look like you have a mile of seat post sticking out since you're long legged, as long as the seatpost is long enough it's a non issue. I think I'm a good 2.5" from getting to the "minimum insertion point" on my stock seatpost so you shouldn't have any issues on a 19" and larger Stumpjumper. With your inseam you'll probably need to be more concerned with proper leg/saddle position rather than the reach to the bars. You may have about 1/4" of safe adjustment with the factory saddle/post so you may still be able to easily choose between 2 different sizes and be close to a perfect fit but it will take a bit of help from the LBS you're looking to buy from. You'll need the saddle set at the correct height for your legs and your kneecap should be above the centerline of the crank while you're at the 3 o'clock position. If you were test riding bikes with the saddle set too low they'll probably feel too small since you're a bit closer to the bars and sitting more upright. If the seat is a few inches too low I could see a 21" feeling as small if not even smaller than a 19" with proper height.

    As for standover, it's nice if you do have a little "breathing" room but it's not the be all end all that some make it out to be. The only time I've ever heard anyone say it's important is when they're a new rider, it's not really very common to straddle the bike with both feet on the ground for most riders. Usually if you come up to a stopping point you'll put one foot down but keep the other on the pedal, if needed you could lean the bike a little to the side to get enough clearance to safely put both feet on the ground.

    If you ask 10 different people you'll likely get 7-8 different opinions on what size you should go with, I think you may be well suited for either a 19" or 21" but would expect the 23" to be too large. The 19 vs 21 would likely be decided by which one goes best with your leg length, you can easily move the bars 20mm or so towards/away from you to suit you.

    Larry
    Larry,

    Your response was probably the most informative and most elaborated that I've seen so far. It is exactly what I was looking for!


    Thank you so much!
    Phil

  16. #16
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    Im 6'4 with a 37" inseam, would I be good with a XL or XXL? (XXL being 24.5 top tube length)
    '98 GT Backwoods

  17. #17
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    Double check the top tube lengths. My 19" Large has a 24.5 top tube length. I'm 6'4"ish but 34" inseam and have a strong preference to smaller frames.
    Most XXL would have a top tube closer to the 26" length. Given your long inseam a XL at least, but stop at a local bike shop and try some out and get their opinion.

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