Originally Posted by
TandemGeek
Belts also seem to lock tandem builders into a fixed stoker compartment length, that is unless there will be a range of belt lengths and/or different size splined gears to allow for shorter or longer boom tubes.
Belt molds are available in a limited number of teeth. As the belts get longer, the jumps in length get bigger. A belt mold can be custom made to any integer number of teeth but the larger the mold, the higher the cost. So, it would be cheaper if tandem makers could agree on a limited number of lengths to amortize the cost of the mold.
How about belt drive for both sides with an internally geared hub? A couple we met were touring with internal hub transmissions. He said that high gear was about 10:1. I think these are 5 or 8 speed hubs. If these hubs could take tandem loads, this could make for a pretty low maintenance drivetrain.