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The difference an inch can make.(8 posts)

The difference an inch can make.okie_rider
Apr 4, 2002 10:33 PM
I am new to riding, and I just can't seem to get fit for a bike. Help...I need some advice.

How much of a difference does an inch make on top-tube length?

I have good standover clearance on a 52cm frame, but I've been told (LBS) my optimal top-tube length is b/w 54 & 54.5 cm, which I can get on a 54cm frame.

Should a person ride the smallest bike that fits, or the
largest bike that fits?

Should I get the correct standover height or correct top-tube length?
re: The difference an inch can make.Akirasho
Apr 4, 2002 11:25 PM
... you'll need a better set of variables to make an accurate assessment.

Fit requires all variables to work in concert... and they vary from person to person (even if they have the same overall height... or the same inseam measurment).

To a degree, the top tube length, while varible by a practical stem length, is a static measurment... I like to buy based on top tube length. While standover height has it's place, chances are, all other things being taken into account, you'll have proper clearances (after all, said height only becomes an issue on a proper sized frame when you're dismounting (either intentionally or accidentally)).

If you received a fitment from your LBS, review the numbers with the shop or compile your on measurments from these links...

http://www.psycle-therapy.great-ride.com/fit_links.htm

All of these offer a variation on a theme... and allow for personal differences (sizing may vary on folks with the same overall height or inseam measurment).

If you have not received a complete fit, again, use the above links or find a shop that will do said.

FWIW, I can ride frames between 58cm to 60cm depending on top tube length with little difference in handling.
re: The difference an inch can make.feathers mcgraw
Apr 5, 2002 5:39 AM
Lemond favors smaller bikes 'cause they're lighter and stiffer. Top tube length is more important to fit than seat tube length, which only affects standover. Standover is much more important on mountain bikes. What length stem does your LBS recommend with that top tube length? What about a sloping top tube frame? That would give you more clearance for a larger size. Finally, geometry varies from maker to maker, you might be able to find one that favors longer TT's.
re: Ride the bike that fits best.dzrider
Apr 5, 2002 5:45 AM
Seatposts, seat rails and stems allow most of us to use a range of sizes without fit problems. That being said, I find that some bikes allow me to feel much more centered and balanced than others. If possible, try a few bikes and a few sizes looking for one that puts your body in the sweet spot.
An inch in TT length is a lot of distance...DINOSAUR
Apr 5, 2002 7:54 AM
As previously mentioned TT length is the most important measurement. You can adjust the ST height by raising or lowering the saddle. You can lengthen or shorten the TT by changing stems, but you can only adjust so far without effecting the balance of your bike. For instance, I could never ride a LeMond as the TT's are way too long for my short upper body torso. You should find out what TT works for you. If you long onto WrenchScience they have an online fit system, but you will need someone to help you take your mesurements. Colorado Cyclist has the same type of system. Take each measurement several times. I used the system on WrenchScience just for the heck of it and it was on the money accept for the stem length.

I've ridden bikes from 57-61cm. I found the larger bikes are easier to compensate for as I just learn to ride in a more stretched out position. With the smaller bikes, I could just compensate so much. They say smaller bikes are lighter. I'd say if you are mulling over two different sizes, you don't have the right bike.

Fit is paramount over anything else (been there, done that).
Know your fit then start looking at those bikes which dial in with your anatomy. It would be really helpful if you located an LBS (local bike shop) that did a fitting for you. A lot of LBS's don't do any type of fitting at all, and a lot of folks are out there riding bikes that don't fit.

Reading you post over again, you are confusing seat tube height (ST) with top tube (TT), or maybe it was just a typo.
Sounds like you have the ST size narrowed down, now find out what your TT should be and you'll have your size..
my wife sure appreciated it (nm)climbo
Apr 5, 2002 9:25 AM
nm
You don't have to thank me. ;-) (nm)grzy
Apr 5, 2002 9:33 AM
LOL (nm)Chen2
Apr 5, 2002 10:21 AM