Originally Posted by
Ghrumpy
About.
7 speed is all narrow or "ultra" spaced, that's why it will fit in basically the same space as a standard 6. But there are a few differences between 7s.
The overall widths are about the same. Shimano/Sachs has the same spacing all the way across. Suntour's outer two spacers are thicker than the inner four though. This makes it tough to dial in the shifting across systems.
But that doesn't mean that Suntour 7 is narrower in any important way - uses the same width chain as all the other 7 speed systems. Which is not what your earlier comment made it sound like - it is no more "ultra" than the rest.