Originally Posted by
phughes
Okay, Surly never made a 64cm frame in the old LHT, and that is the frame I am referring to. So if you have thee new Disc Trucker, none of this applies. It was made to address the smaller frame buying public. And even if you have the old frame, as long as you are happy with the fit, that is all that matters. My comments were based on Surly's reasoning for designing the frame the way they did, they said they saw so many LHT owners with ridiculously high stacks of spacers. That is true, I see that too. Had they bought the next frame size up, they would not have had to have such a high stack. That is basic.
Surly did indeed make the old LHT in size 64cm but dropped the size at some point. The old DT was made in size 64cm till the very end before the new DT.
people chose the too low frames because the lht and dt were too long. They would have been too stretched with the larger frame sizes. Surly has had a tendency to make incredibly aggressive frames. For example at some point the straggler was more aggressive (lower and longer) than the specialized venge. I think the old lht/dt used to be the longest touring frame on the market. Anyhoo the LHT is too long for me and I have to use a 70mm spacer stack. Which brings me to the next paragraph.
As for the new Disc Trucker, it doesn't have weird geometry for a touring bike, it has basically standard geometry for touring bikes from the past. The difference in effective top tube length between the 62cm frame and the 64cm frame is 15mm, and the difference in reach is 10.5mm, so the difference in stem length between the two bikes would be inconsequential to handling and weight distribution. You would be off by all of 1cm, maybe 2cm. There is no way you would have to jump from 90-100mm down to 50-70mm stems to make up for 1.5cm.
here's the deal. A higher spacer stack moves the handlebar back. So top tube length or reach aren't the only defining factors. So if you have two frames with equal reach numbers but different stack numbers, the frame with a lower stack will have a shorter effective handlebar reach if you lift the handlebar to the same level as with the higher stack frame. So when the old or new LHT 64cm frame has more reach than the 62cm frame it moves handlebar reach. But the different stack also moves the handlebar reach. It's double trouble so to speak.