joeyjindan

I am considering buying a quality road bike off of ebay or possibly mail ordering a frame from Europe. I need to know the correct size frame before I buy. I am 6 foot 1 inch tall and have a 32 inch inseam. I was told that I should convert my inseam size to cm then multiply it by 67%. Using this method, the correct size frame for me should be 56cm. The bike shops that I visited recommended a 58cm frame size---they made no measurements just visually sized me up. How big of a difference would it be if I bought a 56cm, 57cm, or 58cm frame?? Could I make any of them work by adjusting the seat height, saddle position, and stem height????

WorldIRC

if urr 6'1 then chances are you have longer arms. you may want a 57 or 58 then.. this way the top tube will be longer therfore letting you spread out your arms father.

KennethToronto

They "visually sized you up"??? Oh geez..what kind of bike shop is that?!

You can try an online bike fit program at www.wrenchscience.com

Good luck

joeyjindan

thanks for the info guys

hey ken, I used that program at wrench science. It recommended a 56 cm frame.

The question is how much difference does a cm or 2 make??? Will I be completely messed up if I go for a 58cm???Moreover, --say I go for a 54cm frame---it's 2cm's less than the wrench science program suggested, is that ok?? My instinct tells me it's better to go for a 58 than a 54. But I'm a newbie, I really don't know much about sizing.

bill_me_l8r

Did you use your pants inseam or did you take the measurement as shown. It can make a difference of 1 1/2 to 2 inches. That migt make the difference between the 56 and 58.

Have fun shopping. You may want to look at an LBS or two and test ride some bikes. You may also want to buy from an LBS instead of the internet for the customer support that an LBS will provide you.

Bill

pokey

You are kidding yourself.2cm makes a big difference.Do you even know the different ways frames are measured and the effect of seat angle and toptube length? Good luck!

bac

There is one component on your bike that is the single most important piece ... fit. If you are going to buy over the net, be darn sure that you get the correct size, or you may be setting yourself up for a serious disapointment.

FYI, I'm 5' 8", and I ride a 54cm frame. Good luck!

Argonne

"I am 6 foot 1 inch tall and have a 32 inch inseam..."

I find this very hard to believe, unless your knuckles drag on the ground when you walk.

A bicycle "inseam" is measured from the bottom of your pelvic bone to the ground.

A tailor's "inseam" is measured from a point just below the bottom of your scrotum, to a point just on top of your shoes.

If you're just going by the inseam of your pants, you'll be on a bike several sizes too small for you. E.g., I am 5'10.5" tall with 32" inseam pants, but for bike sizing my inseam is 34.25".

There are several bike sizing guides out there (wrenchscience, colorado cyclist, rivendell, etc.) but basically to measure your inseam you need to stand straight up against a wall with bare feet a few inches apart, clear any tender tissues out of the way, and the shove a good solid book up between your legs as hard as you can without lifting your feet off the ground. Then mark the top edge of the book on the wall with a pencil and measure to the ground. Books are good because you can lay the edge flat against the wall to make sure you're measuring on the horizontal. It helps to have someone else assist you with this or you're going to have a hard time marking the top of the book without letting it slide down a little.

I'd be surprised if you took anything smaller than a 59 or 60, barring any really bizarre body configuration.

pokey

HaHaHaHaHaHaHa.....and when your scrotum drags the ground you REALLY have a fit problem.

velocipedio

Joey, there's a lot more to bike fit that seattube height. It's the kind of thing you really have to have done properly by a conscientious bike shop -- and not the yahoos who just visually sized you up. Remember. you're spending a whole lot of money here. An ill-fitting bike is worse than useless, it can also injure you.

The inseam X 0.67 formula is only good for seat tube height, it doesn't tell you anything about the top tube length, or wheher you'll actually find the angles of the bike comfortable. Besides, there's an inseam X 0.65 formula that gets quoted almost as often and gives a different seat-tube height. MOreover, you'll find that different manufacturers measure seattube height differently -- some measure from the centre of the BB to the centre of the top tube, other measure from the BB to the top of the TT, others measure to the top of the seatpost.

Take a look at Wrench Science. That's give you an idea of the range of sizes you should be looking in, but to know for sure, you really have to have a proper fitting done.

gabiker

I am 6'2" and ride a 57cm Lemond, however I would be on a 59 or 60 with some mfg, because Lemond measures for the center of the BB to the center of the TT. Lemonds also have a longer TT than most bikes so if I went to the next size up the TT would be to long.

I first questioned the size of the bike when I was being fitted because I thought I would at least need a 58, however after riding for awhile my bike fits me like a glove.

Take the advice you get here and find an LBS to fit you properly and go ahead and do the wrenchscience fit so you will have a little knowledge going end. I did the wrenchscience after I purchased my bike but it all matched.

Good Luck...