25 or 35 chain?

[Alan Ing]

Hi all, this is the fourth year for our team and every year the same questions comes up. We have always used 35 chain and corresponding sprockets, but I can't help but feel they are oversized for the job. Last year we had the drill and atwoods coupled driving 8" wheels at 5-6 FPS not the fastest, but definitely not the slowest. With the wheels we had we got about 160#s of thrust to the carpet.

So, what do you all think? Has anyone had trouble with 25 chain and small sprockets?

What would be the smallest number of teeth that we could run safely? 12, 15, 18?????

Were planning to use both drill and atwoods again with a shifting gear box.

Our transmission spins quite a bit faster this year and one of the problems with the 35 chain is that we really need to use at least a 4:1 reduction with the chain which would mean a running a 10 tooth sprocket (sort of small in the past we have been using 12s ) and I am a bit concerned that there would be more chance for the chain to skip.

Your thoughts would greatly be appreciated.