Road Cycling - Frame Size

Can someone please tell me how to choose the right frame size? I'm new at road biking and want to make sure I'm getting the right size frame before I buy a new bike.
thanks
Matt

Really you need someone who is experienced in fitting bikes to tell you what size you need... the best way is to try a variety of bikes at a reputable shop and see what they recommend.

test ride locally to see what feels best and try using a fit calculator like this one just to get some more useful info.
http://www.competitivecyclist.com/za/CCY?PAGE=FIT_CALCULATOR_INTRO

Go to my website http://www.ProdigalChild.net Click on Bicycles. Go to Page 6; Bike Tech. There is a sizing chart there you might find useful.
By the way I’m no longer in the bike biz, so I’m not trying to sell you anything.

Peter White Cycles has a very good guide to fitting a bike.
The consensus optinion is that length is more significant the height, esp with modern style frames (which have generous clearance).

By the way, how do you measure an existing frame to see what it is?

Patriot

Do some research. There are many different theories about sizing. Plus, different uses, ages and fitness levels influence ideal frame measurements. Long distance tourers, for example, need a more upright, less aerodynamic seating position than racers which may mean a larger frame with higher handlebars.

At the risk of aggravating Seely again, I'll say that sometimes salespeople at bike shops don't take all of these things into consideration when fitting a new rider and the rider ends up with a bad fitting. (I have four bikes. The only one that was fitted by a bike shop is 6cm smaller than the others and it is the worst fit.) That said, unless you =really= know what you're doing, you'll do better with a LBS than by guessing on the internet because you can at least do a test ride. Unfortunately, new riders don't often know how a road bike =should= feel and test rides can be too short. That's why you should ride several and when you narrow your choices down, try to get an extended ride.

The size of the frame is determined by measuring the seat tube from the center of the bottom braket to the top of the tube. Some manufacturers measure to the center point of the top tube. This size is only the beginning, though. The top tube length per each size varies by manufacturer and model as do the head and seat tube angles. Compact geometry further muddies the picture. That's why bikes that are ostensibly the same size can have very different fits. So you still need to test ride, even if you think you know your size.

test ride locally to see what feels best and try using a fit calculator like this one just to get some more useful info.
http://www.competitivecyclist.com/za/CCY?PAGE=FIT_CALCULATOR_INTRO

This is a great site, you've just gotta make sure you get the crucial measurement of your inseam correct.
Do it a few times to make sure you've got it right

In answer to Patriot's question, "How do you measure an existing frame to see what it is?


I always measured my frames from the center of the bottom bracket to the top of the seat lug because this is standard practice with English builders. Italian builders and most others measure center of BB to the center of the top tube.

You need to be aware of this especially if you are buying a used bike unseen on ebay for example. If the person selling has a 56cm. frame and is measuring center to top. If you assume he is measureing center to center and you buy it you end up with a frame 2cm. smaller than you expected. (A 56cm. center to top is roughly a 54cm. center to center.)

Either way is correct; just make sure the buyer and seller are on the same page.

Thanks for the info guys!
Matt

At the risk of aggravating Seely again, I'll say that sometimes salespeople at bike shops don't take all of these things into consideration when fitting a new rider and the rider ends up with a bad fitting..


I'm keeping an eye on you... ;)