Yes, the only limit on exposed steerer on Surly frames is aesthetic. This may not be the case for other manufacturers.
I don't have an encyclopedic knowledge of top-tube lengths, but that info is available on the Internet for anyone to compare. But yes, since bar height doesn't have to be a variable on the LHT, top tube length is the most useful sizing parameter. Very often people who want to buy a Surly will use Riv's sizing scheme. But like someone above said, the Surly 58 cm is more like a 60-61 cm if you measure center bb to top of the seat tube. And the top tube in most sizes of LHT or Cross-check is very close to nominal frame size (i.e. 58 c-c on a 58 frame). I have no idea if this makes the frame more suitable for drop bars or for porteur bars, but for most people who go with Riv's PBH-based sizing guideline and drop bars, it results in a stem that's sub-90mm (short) and tightish stand over. Twice I've had LHT customers who couldn't let go of the Riv size recommendation despite my having explained this ad nauseum...and then a week after the purchase ask to do a frame swap for a smaller size. The customer is always right! -- You received this message because you are subscribed to the Google Groups "RBW Owners Bunch" group. To view this discussion on the web visit https://groups.google.com/d/msg/rbw-owners-bunch/-/s-hjcjTjoaYJ. To post to this group, send email to rbw-owners-bunch@googlegroups.com. To unsubscribe from this group, send email to rbw-owners-bunch+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/rbw-owners-bunch?hl=en.