Framebuilders - Frame sizing w.r.t. handlebar choice

Hi!

I'm trying to decide on a size for a new frame. Salsa Casseroll, most likely.

The thing is, I have a Raleigh Sports (555mm top tube, 72.5 degree seat tube as far as I can measure) whose fit I adore. But it has swept-back North Road handlebars, and I want drop bars on my new road bike.

My question: how does handlebar choice affect frame sizing? Not at all? Should I order up or down? Is this not enough information?

Thanks much.

Well, forget it...I found a shop that stocks the complete bikes, so I'll get to try them on.

I'll report back.

I tried on a 51 cm Salsa Casseroll last evening, and it fit very well. It has a 545 mm top tube/73.5 degree seat tube angle, which corresponds with the Raleigh frame (Sheldon Brown's rule of thumb is that for each extra degree of ST angle you can take off 1 cm of TT).

So I'd conjecture that handlebar choice doesn't affect frame sizing.

That's all well and good in practice...but how does it work in theory???

LOL

You don't pick a frame on the basis of what handlebar you want to use. You pick the frame on the basis of your body, and then the stuff you want to hang on it comes after. Your choice of handlebar style (shallow drop, deep drop, long ramp to the hood or curve down more quickly) may affect what length of stem you end up needing though, if you're into very precise fitting.

Since this is the framebuilding forum, and not say, the comercial bike fitting forum, I would say that handlebar choice does affect frame choice.

For the kind of frames I build I don't really vary the seat pedals relationship, though I'm sure somewhere along the line that would happen with some bike types. I might vary seat tube angle depending or stay length, but the seat in relationship to the BB or cranks would be the same.

What changes relative to the handle bars is going to depend on my posture. In my case I build mostly touring bikes and my position on the bars is a little higher that I would like, and probably averages between the tops and the drops, I ride both, and have several positions in-between. Overall that might not be all that different in frame terms than some upright handlebars. Of course there are bike with drops that are very low in the front, and bikes with upright handlebars that have completely different geometry like comfort bikes, or short top tube MTBs. But as has been observed in some catagories thesame frame can be used for both handlebar types, or within a stems' wisker.

For the kind of frames I build I don't really vary the seat pedals relationship, though I'm sure somewhere along the line that would happen with some bike types. I might vary seat tube angle depending or stay length, but the seat in relationship to the BB or cranks would be the same.

...

But as has been observed in some catagories thesame frame can be used for both handlebar types, or within a stems' wisker.

Awesome. Just the insight I was looking for!