Compact Frame

[geekgirl]

I also ride compact or semi-compact frames -- a Salsa Casseroll as a daily commuter and a Klein Quantum as a go-fast fun bike. I have a bit of a longer torso (at least compared to most women, I guess) and short legs, so I feel more comfortable on compact frames.

You just have to be careful if your proportions are different, though, and pay attention to the "effective top tube" measurement. People get into trouble on compact frames when they think that just because they can stand over the top tube with clearance, then the bike will fit -- often times I think the reach will be too long, unless you have a longer torso.

The only way to really find out what fits is to go and try out a whole bunch of different bikes -- you'll figure out which brand's geometry works for you, and which ones don't.

[7rider]

My bike has - I think - 12 degrees of slope to the top tube. It's very compact - looks tiny...feels big. I love it. It's very sure-footed, tracks like it's on rails, and fits me like a glove.

Here's Seven's take on sloping top tubes/compact frames from their Custom Kit booklet:
http://www.sevencycles.com/buildingb.../customkit.php
(see page 6 of the pdf on that page for a graphic illustration of the benes of it).

Why Incorporate a Sloping Top Tube?
About 85% of the road frames Seven builds have some degree of slope to their top tube. We incorporate top tube slope into most designs for one primary reason: Optimal fit.
A sloping top tube allows us to accomplish three goals:
1. Top tube slope allows us to properly set the handlebar height relative to the saddle height—we call this dimension the "Handlebar Differential"—to provide optimal comfort and proper weight distribution on the front wheel for ideal handling. As we increase the length of the head tube, the bar height begins at a greater height relative to the saddle top.
2. With a taller head tube length, top tube slope allows us to provide an optimal Handlebar Differential without the use of excess spacers under the stem. This in turn allows for greater bar height adjustability in the future.
3. Finally, with a taller head tube, sloping the top tube allows for sufficient standover clearance at the mid-point of the effective top tube.

[Zen]

Exactly what qualifies a frame as compact?

[geekgirl]

Compact geometry means the bike has a sloping top tube, whereas a traditional geomety bike has a completely level top tube. I believe Giant may have been the first to come out with compact frames for road bikes -- here is a link to the Giant website with more info.

[Zen]

Heh.
I've just always called it "a sloping top tube"