Originally Posted by
bykemike
That is a great looking drive you have there, it looks as if the chain ends up being almost the same in the inverse position. Very cool!
It is practically the same (there is a 1T difference total between the two sets) which was necessary for the vertical dropout because I could not tension the chain.
First I found a magic gear combo for my low range, and then swapped some cogs until I found a magic gear combo for the high range. I forget the T counts (at work presently) but can look them up later.
I racked my brains for a bit trying to come up with a SS system for mtbing hills that would allow reasonable up and down performance and this is the most practical solution to give a wide enough range choice without requiring tools to swap.
The trick is to determine which direction is most important (up or down hill) and choose the gear combo that meets the need. Then mess with the inverse gearing to maintain the T count and give the best opposing performance. That allows the widest range possible.
A road "pass hunter" bike could do the same if the hills are long and sustained in a way that makes the 30 second swap at the top and bottom worthwhile.