BBSHD gearing range for velo with cargo trailer?

[ToxicFox]

So I currently have an on road bike, and an offroad bike. I’ve been eyeing the mid drive Baofang kits for my offroad, and adding a small trailer behind it to pull my canoe. In diving down this rabbit hole, I have went off on the tangent of velomobiles, and am now considering building a custom velo & trailer combo. To meet some secondary needs that will come into play later, but not immediately, I decided to go with the 750 W version of the BBSHD. I’m leaning towards a tadpole trike design, full suspension(non negotiable), possibly leaning capabilities for steering advantages.

My question is what is an appropriate gear set to attempt to achieve? I’m going to lean on the conservative side and assume heavy. I weigh roughly 200 lbs give or take 20 lbs depending on weight cycling. It's an aluminum canoe so assume another 150-250 lbs for canoe and gear that will be on a trailer. I live in an area that is mostly flat, but canyons make for some rather steep hills getting to/from some locations. I would like to have a reasonable cruising speed so I don’t take forever to get places, but at the same time I don’t want to grenade my drivetrain trying to get up a hill at full weight. Any recommendations based on experience for a solid gear set? My offroad has a shimano trigger shift, and I really prefer that over my road bike’s lever shift(hate those things, but the bike was free). I have no personal frame of reference for recumbent/velomobile gear ranges, or what they feel like under load, so any decent advice on how to spec out a gear range would be greatly appreciated.

 

[amberwolf]

I'd recommend going to one of hte various simulators (like the trip or motor ones at ebikes.ca) and using the real conditions you're going to need to operate under, use the middrive option and setup a system that emulates the middrive and battery you're going to use in power capability and limits. It doesn't have to be exact, just usefully close. The idea is to experiment with the gear ratios vs the various sets of conditions (flat, uphill, windy, no windy, etc etc) to get the most efficient result in each gear, or at least to not approach / exceed any limits in the highest and lowest gears.

Then you can look for drivetrains that will either work with the shifter you have / like, or can be bought with that shifter. (even if you have to buy an old bike with it all on there already to get it, and move it to the bike youw ant it on).

Keep in mind that your crank length will also factor into this for your pedal-power when the system is not working or battery is out of juice, etc., and it's not uncommon to use shorter cranks for a 'bent than you mgiht use on an upright.

You're pedalling in a different way with different muscle groups used differently, from a different position, than you would on an upright. You're not using your weight and gravity to help; you're using your back and thighs, etc., so it's usualy easier to use a higher cadence so you don't have to push so hard, and so shorter cranks spinning faster.

Since your motor will use the same gears your pedals do, you'll probably end up with a compromise to make them both work ok...making one work perfectly may make the other work terrible, depending on exactly how you choose to setup the drive system.

The gearing also depends on your wheelsize and actual speed required, and actual torque required.