I was looking at the drive-belts on a neighbor's Harley yesterday.
I did not take any measurements, but the "gear"-ratio looked about what a rotary engine could use.
And the power through the belt on this Harley chopper must be comparable to that of a minimally powered rotary.
So I would like your thoughts on:
   Reliability of belt-speed-reducers
   Weight of a typical installation.

As I mentioned in an email a month or two ago... I keep thinking of the day when I might want to register my airplane-in-progress as an LSA, just in case the years on this old body start to take their toll.,

I am building a Bearhawk Patrol, which is supposed to be about 950# dry with an O-320.
So far I have not been nibbling away too much extra aluminum in an effort to keep it light. I would rather skimp on power than in structure.

Robin Berglund

Belts are possible but don't expect much savings on weight if any.
The belt requires periodic replacement.
Cowl packaging would be more difficult as well. I recommend sticking
with Tracy's 2.85:1 planetary gear box. Figure 40 pounds for Tracy's GB.

Paul Lamar