Touring Equipment

The Salsa have a slightly relaxed seat tube on the 54cm (700c), so theoretically the reach is similar with an in-line seatpost instead of a setback.

Your Surly top tube is around 53cm, seat angle is 74.5 degree which you end up having a setback seatpost to compensate.

Salsa's top tube is 54cm, but with a 73.5 degree seat angle, mean you can get an in-line seatpost and the reach will be similar*, the only concern is whether the 150mm headtube might be too long, but idea for slammin' it, but considering you have more spacers on your bikes than I ever have in my lifetime, I think it'll be fine.

*think -1 degree = +1cm on top tube

will take a look at that then. I'll get the LHT out on the weekend and take a tape measure to it and see how it compares