Question on Bike Frame Sizing

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2005-05-13 1:04 PM

New user
6

Massachusetts
Subject: Question on Bike Frame Sizing
I'm in the market for a cheap entry level bike and have come across what seems to be a good deal on a Giant TCR 1 (2000), Size Large (compact frame). I can't test ride the bike before I buy it (needs tubes and tires). I am 5' 9" and have a 32" inseam (actual, not pants). I went to the Giant website and according to the charts I should be on a Small frame.

Here's the Giant sizing chart.
http://www.giantbicycle.com/us/000.000.000/000.000.000.asp?sPageID=...

Now I know I'm not very tall, but I would have guessed I would be Medium. So, my question is, can somebody my size fit on a Giant Large frame (maybe with the seat all the way down)?

Thanks,
Cesar




2005-05-13 1:29 PM
in reply to: #157188

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Pro
4228
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Broomfield, Colorado
Subject: RE: Question on Bike Frame Sizing
with a bike that's too big, yeah you can put the seat down, but the bigger concern is going to be the length of the top tube....you will likely have to reach too far and can have back pain, etc.  Good deals are great, but make sure it's for a bike that fits!  I made that mistake myself....lesson learned....   Take your time in bike shopping, be particular!
2005-05-13 1:35 PM
in reply to: #157188

Champion
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Subject: RE: Question on Bike Frame Sizing
The problem with trying to fit on a large frame and just lowering the seat, is that it will probably not suit you in other areas as well. The top tube will surely be longer, and combined with a longer stem that is normally used on larger frames, it may make it uncomfortable to reach the handlebars, and it'll affect the efficiency of your pedaling. I'm not sure how their generic sizing correlates to actual metric measurements, but as a guess I'd say you should be riding on something in the 54-56 cm frame size. The trouble today with frame measurements is that things like sloping top tubes have opened up a can of worms as to how the sizes are actually measured, but in general, the 54 cm is a measurement from the centerpoint intersection of a horizontal top tube and the seat tube to the center of the crank.
2005-05-13 1:39 PM
in reply to: #157188

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Member
86
252525
Austin, Texas
Subject: RE: Question on Bike Frame Sizing

I'm 5'11" and would find a large TCR way too big for me.  If I'm not mistaken, it has a 58cm top tube.  My road bike and tri bike have  56cm top tubes.  You can change stems to compensate for minor differences in tt length, but running a really short or really long stem will negatively impact handling - and those issues will be even more pronounced if you throw a set of aerobars on the bike.

Keep in mind that no matter how much it costs, if it doesn't fit, it isn't a good deal.  Wait for something that fits. It's also a good idea to pay for a professional fitting and then you'll know exactly what size you need and can compare geometry charts on different bikes to see which ones will work for you.

2005-05-13 1:57 PM
in reply to: #157188

New user
6

Massachusetts
Subject: RE: Question on Bike Frame Sizing
Wow, that was quick! I'll take your collective advice and keep looking.
Thanks,
Cesar
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