100 tooth transmission vs chain 3 to 1

[jimst1]

I couldn't find much searching, so.. I will be putting a 49cc Hungsang on a near heavy trike. Any one know the reduction of the 100 tooth transmission? I am facing some 20% hills and want to make it with a little help from me. Wish I'd bought a 5/8" shaft motor. pics at http://www.pbase.com/llmjls/inbox&page=18