frame size

Martin

I'm also looking to buy a new road bike after 20 years with my trusty old 531 tubed tourer and a more recent mtb that is seeing a lot of road use. I found this page whilst surfing and don't know if it will help, you'll have to be a dab hand with the tape measure

http://www.bsn.com/Cycling/ergobike.html

All the best
Sean

Greetings Gymbob!

I am by no means the authority on bike sizing, but one thing that I wanted to pass on only because I just went thru the months and months period of research and info gathering prior to buying my road bike.

When a bike frame is labelled 56 or 68 or 60 etc, find out if that measurement is what they call CtC or CtT (Center to Center) (Center to Top) because that effects the seat tube length and a variety of other points in the bikes geometry as well.

Trek, for example is a flyer in the group because even though they are labelled as Center to Top for frame size, they actually measure from Bottom Bracket center to the very top of the seat collar (not the seat tube) and that adds a centimeter or so to the distance...

A Frame measured CtC will be slightly smaller than one measured CtT SO in the case of Trek (5000 series specifically) what is marked as 58cm (CtT) might be closer to another brand marked 56cm (CtC)

It was all very confusing to me and in the end because every bike manufacture appeared to use a slightly different method, I think the best course of action is what I did. To simply head down to a reputable LBS and have a trained expert measure you on a fitkit device and actually watch you ride... Never rely on something as arbitrary as just standover height. I learned that in many cases that is FAR down on the list of important sizing considerations...

Good luck in your search and purchase!

Feanor

Quoted post said:

Originally posted by Feanor
Greetings Gymbob!

I am by no means the authority on bike sizing, but one thing that I wanted to pass on only because I just went thru the months and months period of research and info gathering prior to buying my road bike.

When a bike frame is labelled 56 or 68 or 60 etc, find out if that measurement is what they call CtC or CtT (Center to Center) (Center to Top) because that effects the seat tube length and a variety of other points in the bikes geometry as well.

Trek, for example is a flyer in the group because even though they are labelled as Center to Top for frame size, they actually measure from Bottom Bracket center to the very top of the seat collar (not the seat tube) and that adds a centimeter or so to the distance...

A Frame measured CtC will be slightly smaller than one measured CtT SO in the case of Trek (5000 series specifically) what is marked as 58cm (CtT) might be closer to another brand marked 56cm (CtC)

It was all very confusing to me and in the end because every bike manufacture appeared to use a slightly different method, I think the best course of action is what I did. To simply head down to a reputable LBS and have a trained expert measure you on a fitkit device and actually watch you ride... Never rely on something as arbitrary as just standover height. I learned that in many cases that is FAR down on the list of important sizing considerations...

Good luck in your search and purchase!

Feanor

Most use one method.Wrench science should figure it out for ya.