I need to buy a bike for my wife, she currently rides a C'Dale 54cm top tube with a 80mm stem, and 4cm of spacers (get the picture?). I think that ideally if we could find her a 53cm or so t-t with a longer head tube we could use a longer stem that will improve steering. Any ideas?

spv

Trek Pilots and similar bikes are more upright.

To get an accurate recommendation, you really need to post the actual HT length, with the headset and spacers. These days it makes a difference if the frame uses a conventional threadless or integrated headset.

Also, from typical C'dale geometry charts, the only frame with a 54cm TT is a non-stock 53cm frame. The 54cm frames have a 54.5cm TT.

The frame reach, that affects the stem length required, is determined by both the TT length and the seat tube angle. If you have both, or the frame model, I can probably find the dimensions.

Offhand, frames to consider are the Specialized Roubaix and Allez or Trek Pilot series.

I assume that in additional to the 4cm of spacers, you're also using a high rise stem? If not, flipping a stem will raise the bars anywhere from 1.5 to 4cm, depending on the angle.

You probably won't gain more than 10mm in stem length, since most frames just don't vary much when a proper reach calculation is made. It won't make much difference in the handling. Differences in the steering trail will have a greater affect.

She is coming off a C'dale R600 (roughly 54cm tt)

4cm spacer with a high rise stem is correct, can't remember the angle 24 degreeish?

Slacker angles would probably suit her well.

Steering trail? Can you expand please.

Wife has great form, very strong probably rides 3-5 hours a week spring through early fall. My impression of her fit has always been, that it's damn near perfect other than the 80mm stem which made me wonder if the bike was a little twitchy. BTW C'dale had a Ouzo Pro fork.

Thanks for all your help!

A stem difference of a few cm will make no difference in the feel of a bike, all things being equal. (That is, the contact points are the same)

http://www.kreuzotter.de/english/elenk.htm

If you measure the height of the handlebars, vertically, from the floor to top or the bars, I can tell you what head tube length, spacers and stem angle are needed.

I'll assume that you now have a 54cm frame with a 54.5cm TT and 74 degree seat tube angle.

Why not custom? She's not putting in a whole lot of hours, but that doesn't mean you can't love her enough to deem her worth a real bike.:D