Mid drive recumbent fuel efficiency considerations.

[BCBeaver]

I have an HP Velotechnic Street Machine GTE. It's a sweet full suspension recumbent suited to long distance tours. To that end I'm looking for a very fuel efficient mid drive to mount up and tour on. I'm thinking 2 chain rings up front and a wide range 9 speed on the back and I should be able to climb steep backroads and fly on the downhills even with the smallest of motors.

My thought is that a Tongsheng TSDZ with torque sensing would be most efficient because you can't get lazy as with a Cadence sensing drive.

What are you running and what kind of fuel efficiency are you getting out of your mid drives?


https://www.btn-ebike.com/product/E...W_48V500W_TONGSHENG_TSDZ2_Mid_Drive_kits.html

 

[fooferdoggie]

sadly the only really efficient guys are the big guys. only 36v and a lot or range but you cant add one to your bike. my Bosch going at 20 to 22 at the next lowest level I get about 38 and lower I get maybe 50 but those higher speeds eat a battery up.

 

[BCBeaver]

The big guys? Like Bafang? I never really thought of Bosch as "the big guys," Bafang is bigger in every way other than price.

Your mileage numbers are unimpressive you might want to see if you've got a brake dragging or some other issue. If I hop on a Bulls with a Bosch Cx and 500wh battery I can get 120 to 150 km out of it riding about 30kph.

 

[fooferdoggie]

The big guys? Like Bafang? I never really thought of Bosch as "the big guys," Bafang is bigger in every way other than price.

Your mileage numbers are unimpressive you might want to see if you've got a brake dragging or some other issue. If I hop on a Bulls with a Bosch Cx and 500wh battery I can get 120 to 150 km out of it riding about 30kph.

volume yes but they are not bosh or Shimano . they are not dialed in and as efficient. you just use a bigger battery instead of making the system more efficient. going over 20 really eats into the battery. but my bike is only rated at 60miles on eco mode and that would be below 20. plus my energy levels still have ways to go to get more efficient.

 

[BCBeaver]

Volume of sales they stomp Shimano and Bosch. There is this little country with a small population called China where Bosch and Shimano hardly exist, perhaps in N America and Europe, Bosch reigns supreme but worldwide it's Bafang all day.

On a recumbent, 30kph (~20mph) is easily achievable with no electric because you present a small wall to the wind, so I'm looking for something with no speed restrictions. I don't need tons power, I've got that on my commuters. My Bafang Ultra is a pig but nice when I want to climb hills fast, I burn about 12Wh/km,commuting at 40-50kph on the flat and 25 up the hill to my house, it would be horrible for a touring setup. My BBS02 used to burn about 6Wh/km about 6-7kph slower over the same commute, then I upped the amperage so now it's thirstier. The increase in power is negatively disproportionate to the increase in speed and climbing ability.

I have no experience with the Tongsheng torque sensing mid drive but i suspect it might have decent efficiency. I'd ask in the Tongsheng forum but there isn't one.