Buying online by numbers only?

dosthecat

I want to buy a new carbon frame that fits the set up on my current steel frame but I'm a bit worried about choosing the correct size as unfortunately I'll have to buy online.

My current frame 57cm frame has a Top Tube measurement of 55cm (horizontal) of which 40cm is reach and my saddle setback is about 8.5cm. Can I confidently buy any frame with similar reach (or less)? The stem I have is 90mm.

If I buy a frame with a longer T.T but lesser reach is it simply a case of moving the saddle forward to achieve a similar position to the one I currently have or am I missing something?

I would greatly appreciate any opinions folk have to offer.

Thanks

anto164

Saddle position needs to be done so that you're pedalling correctly. Stem length effects reach. So if the frame has a lesser reach, you may need a longer stem.

dosthecat

Yes, of course, thanks for that.