Singlespeed & Fixed Gear - Frame Size and Measurement.

This is an issue that has confused me, since I always thought a frame was measured by standover height.

I have a 29 inch inseam/stand over. My Raleigh has a 55.8 TT and 48 ST. I feel that I need to stretch forward a little more since my stem is short.

I want to buy an IRO but the smallest, which I thought would fit, judging from my current road frame measurements, the smallest won't fit.

Is there a fee to be measured at an LBS with the fitting gear?

This is not IRO specific. I want to learn about this for knowledge's sake.

Can someone really break this down in lay-terms?

find somebody with an IRO and test ride it.

http://www.sheldonbrown.com/frame-sizing.html

Are you sure you know your true inseam? I'm not trying to patronize you, so don't get mad. I just thought this might be useful.

Inseam Measurement

Materials:

A friend (makes things easier)
Book with a broad spine such as a small dictionary or textbook
Measuring tape
Flexible pants (sweatpants, pajama pants, even no pants)

1.) Stand up straight with your back against a wall and your feet flat. Your feet should be a shoulder under your shoulders.

2.) Take a large book and seat it firmly against the wall so that the spine is facing up and perpendicular to the wall.

3.) Pull the book snugly up under your crotch until you can't pull it up any further, but don't hurt yourself.

4.) Measure from spine of the book straight down to the floor to get your inseam.

I did that for my hand-made frame(hopefully coming soon). It came to 31 inches. I guess it is good for me, then. But I still want to know what this means for everyone else. Like I said, this is not for or because of any specific frame I am getting. I just want to be informed.

I have a 29 inch inseam/stand over. My Raleigh has a 55.8 TT and 48 ST. I feel that I need to stretch forward a little more since my stem is short.

I want to buy an IRO but the smallest, which I thought would fit, judging from my current road frame measurements, the smallest won't fit.
That bolded part is what has me scratching my head. Most frames have the top tube and seat tube at damn near the same lengths. Maybe a picture would help?

Aside from that, I usually size a frame by the top-tube length and that's it. Standover doesn't really come into play unless you're talking about mountain/CX bikes, IMHO.

there are a couple different fit calculators available online. i recommend using them (they give pretty much the same directions as ken wind, and then you put the numbers in, and you get a result) in combination with what you are and are not comfortable riding (based on experience) as well as the experiences of other people your height. maybe other people can chime in with links to fit calculators?

re: IRO, tho' your question wasn't aimed at it. how tall are you? maybe the 53 is a good option, since you're riding 56cm tt, short stem, and feel stretched out.

That bolded part is what has me scratching my head. Most frames have the top tube and seat tube at damn near the same lengths. Maybe a picture would help?

Aside from that, I usually size a frame by the top-tube length and that's it. Standover doesn't really come into play unless you're talking about mountain/CX bikes, IMHO.

Some of the new "ralieghs" (the brand has outlived the manufacturer) have semi-compact geo that would give numbers like this if you didn't do a "virtual" ST measurement.

Some of the new "ralieghs" (the brand has outlived the manufacturer) have semi-compact geo that would give numbers like this if you didn't do a "virtual" ST measurement.

This is an old Raleigh. It is a Nottingham made TI Raleigh. I have no idea of its actual age but when I bought it, it had never been built up. The LBS owner here confirmed that as he was installing the BB.

My measuements might be a little off but its about right - 22 inches C to C = 55.8 TT, 19 inches C to C = 48.2 ST