A little help please - Cargo Hub Motor

[NPC Brown Cow]

Those structural deficiencies may not exist in the rotovelo, and should be readily addressable if they do exist. The chain problem should be solvable as well. Go to a bigger low gear cassette, and use a stronger (less speeds) chain and cassette. 8 speed might be a sweet spot. Any chain strength issues with a BBSHD have been addressed by the hotrodder MTB crowd, I am sure.

The Jouta was using 7.3mm (KMC z50), 7 speed chain. The only thing below that (in bicycle chain) is single speed.

 

[amberwolf]

I tried a BBS02 on my Quad, which is about the same weight as the Rotovelo. On those slopes it either winches it's self up the chain, collapsing/telescoping in the front boom, or snaps chain. This is the general problem with a mid-drive solution.

As I noted previously, there are a number of types of middrive, and they don't have to mount on the boom, or even at the front end of the trike at all, and could still use the pedal chain system and gearing at the rear wheel.

If chain snapping is still found to be a problem even with a separate shorter rear chain section, then the rear wheel can be changed for one with an IGH capable of the torque levels required, and the single-sprocket input to it (and the one on the motor output) can be changed to one that fits a higher-torque-capable chain size. The lighter bicycle chain can still be used for the longer front run.

As for reverse, I can always use a small dedicated motor and a disc brake cog, like these https://www.unicycle.com/nimbus-club-giraffe-plate-sprocket-for-wheel/, for that since the back wheel doesn't have a break (but the hub is made for disc brakes).

That's a fairly easy thing to do; as long as it will only be used on flat ground at very low speed, you can use a very small brushed motor with a gearbox, similar to a window-crank motor from a car but probably capable of more torque. A simple reverse button can be used to control a simple high-current relay to apply power directly to the motor from the main battery, no controller needed. Would require a clutch or freewheel of some type at either the motor or wheel end so you are not backdriving the motor when going forward.

Essentially the same as the various very-low-power left-side "middrives" posted around ES and elsewhere over the years, except designed to run only in reverse.

 

[Chalo]

The Jouta was using 7.3mm (KMC z50), 7 speed chain. The only thing below that (in bicycle chain) is single speed.

Z50 is lightly riveted, so it can be pinned back together without the use of a snap link. That makes it more likely to pull apart in a condition that exerts a spreading force on the side plates. Z72 is a similarly priced chain that is much more heavily riveted.

Getting a good join with a pinned chain like Z50 is up to the skill of the installer. Hint: if you get a tiny sliver of metal after pinning the chain, you screwed up. (But that's not the only way to screw it up.) Moral: use chains that come with a snap link. They're better.

 

[NPC Brown Cow]

Z50 is lightly riveted, so it can be pinned back together without the use of a snap link. That makes it more likely to pull apart in a condition that exerts a spreading force on the side plates. Z72 is a similarly priced chain that is much more heavily riveted.

Getting a good join with a pinned chain like Z50 is up to the skill of the installer. Hint: if you get a tiny sliver of metal after pinning the chain, you screwed up. (But that's not the only way to screw it up.) Moral: use chains that come with a snap link. They're better.

I wondered about the Z50, it's what shipped on the Jouta and it was one long piece (and twisted as heck). I had to break it and insert a master-link to straighten it out before I could even finish assembling the quad.