Workman side by side trike motor upgrade?

[Dave P.]

Hello my name is Dave, I am here to find information for my brother who has a sight problem (not blind) long story.
He has a Workman Trike [https//www.worksmancycle.com/sbst-3cb.html] total weight of him his lady friend battery pack
and trike is about 520 lbs. The front hub motor is gutless, struggle's going up a small incline. I would like to know where
I can find in the United States a dealer that sells Cromotors. He would like to price out a 60A rear hub motor laced to a
26 inch wheel to accommodate a motorcycle type tire (left rear right rear). Keeping the wimpy front motor so the rear
motor will have a side mounted seat throttle.
(If I lost ya'll to the point that it's clear as mud with the improper lingo, please ask questions so we can be on the same page)

this is not a joke, it's a real project, I need a little guidance with
Thanks for any input
Dave



[moderator edit to format pic]

 

[Hwy89]

Yes you "lost" me.
Why not just install a stronger front hub motor or a mid motor that would drive both rear wheels through the gears?
I don't know what you mean by "side mounted seat throttle" but any throttle that requires the rider to take his hand off the bars would be dangerous.
Powering one rear wheel on a trike would really create strange handling characteristics. Trikes are hard enough to handle without adding power to the left rear wheel which will constantly make it want to steer right.

 

[Dave P.]

Yes you "lost" me.
Why not just install a stronger front hub motor or a mid motor that would drive both rear wheels through the gears?
I don't know what you mean by "side mounted seat throttle" but any throttle that requires the rider to take his hand off the bars would be dangerous.
Powering one rear wheel on a trike would really create strange handling characteristics. Trikes are hard enough to handle without adding power to the left rear wheel which will constantly make it want to steer right.

Valid point Hwy89
But adding more power up front won't work... front is too light.
Design positraction unit ??? that might get a little testy.
A tadpole trike might be the answer. Then another idea
he might be money ahead to buy a prepaid Uber card.

 

[Chalo]

The trike's rear wheels are single sided and fit on special drive axles. There's no kind of hub motor that will go there. Even the few stub axle hub motors I've seen are designed for a fixed stub, not a free rotating axle.

They need a more powerful, high torque front hub motor. Maybe a 12t MAC with a 50A controller? Not too much voltage, either, because faster than jogging speed with two fatties on one of those deathtrap trikes would not be a good idea.

But adding more power up front won't work... front is too light.

Less weight than what's on the rear axle is not the same as "light". It would probably be fine. If not, mount the battery on a front rack.

The other alternative is to use something like 2-4kW Cyclone motor to drive the rear axle. That would result in one-wheel drive with the drawbacks that have already been discussed.

 

[Dave P.]

Thanks for the replies... assessing the issues with this trike, I think it would be like putting good money on bad idea.
Further ahead to pay the price of a well engineered trike. And roll with the idea of "Stock Is Best By Test"

 

[Rassy]

I have a BBS02 on a delta trike which drives just the left rear wheel. I don't experience any "pull" to the right, at least not noticeable. I do have the top speed
of the BBS02 limited to 20 MPH.

I did have a brake issue on one of the rear disc brakes, (They are both activated by a single brake lever with a balancing mechanism built in), which resulted in the left rear brake engaging before the right one, which caused a definite pull to the left. But a brake is a lot stronger than the acceleration provided by the BBS02.

On the other hand, I had another delta trike with just the right rear wheel driven by the pedals, and when going too slow up a 20% grade (my driveway) the front wheel would slide to the left with each pedal stroke, and no chance of moving forward from a full stop. So I do agree it can be an issue, depending on your use.

 

[ddk]

according to what info I could source about this trike is the motor supplied by workman is a Direct-Drive (DD) hub motor.
From my own experience with a 500# trike, a DD hub motor can sometimes be "gutless" on any grade.
A geared-hub motor in the front wheel would be the better choice, as Chalo suggested.

The trike uses Ashtabula cranks-
To Rassy: does this preclude the use of a BBS02 or equivalent? I'm clueless. (as usual)

Note : I've added a rear motor to a number of delta trikes with 'one wheel only' driven (as most delta trikes use) and have never felt the trikes pull to one side or another.

Because of it's gear setup this model of trike would be very easy to add a 'DIY' rear motor should one be slightly mechanical-minded.

 

[Chalo]

The trike uses Ashtabula cranks-
To Rassy: does this preclude the use of a BBS02 or equivalent?

A BBS02 can be fitted, but only if eccentric adapter cups are used. Luna Cycle has some for that purpose. A normal concentric American-to-British bottom bracket adapter doesn't leave enough clearance for the motor.

 

[ddk]

Hello my name is Dave...

Hi Dave... Noting that a hub motor mounted in a wheel would not work at all, IMO the best solution would be adding a Bafang BBS02 -or- BBSHD kit, including those adapter thingies Chalo just pointed out and an additional battery specifically for the kit's power because I doubt the battery the trike currently has can source as much current as a two motor system would require.
Install the kit as if the other motor didn't exist and the trike will go much gooder. esp. with both motors engaged.
I'm not too thrilled about the three speed transmission but the trikes' geared for low enough speeds that it shouldn't be an issue.
And I do suggest using two motors in loo of "one really big one" for the front wheel as this avoids lots of issues like, motor heat, weak forks, blah blah blah and all the rest of the technical jargon.
...again, IMO

 

[Rassy]

I recently helped a friend install a BBS02A on a bike that had a one piece crank (had to look up what an Ashtabula crank is). We just installed a standard bottom bracket adapter, after checking clearance, and there was enough clearance for the BBS02. Probably could have been a problem if the bottom bracket housing was thicker, such as might be found on an aluminum frame bike.

I can contact him and find out just which adapter he purchased and any issues that might be important, but I know it was not offset like some have recommended was necessary.

 

[Chalo]

[...]after checking clearance, and there was enough clearance for the BBS02. Probably could have been a problem if the bottom bracket housing was thicker, such as might be found on an aluminum frame bike.

Worksman cycles have been made in Manhattan for millions of years from melted down steam engines or something along those lines, and I would not count on that kind of lucky break.

It's good to know that it's sometimes possible to use a more widely available concentric BB adapter.

 

[profe]

Old thread, but I just ran across it while researching my own side by side project. Did anything ever come of this? I'm planning on building one with a torque sensing mid mount motor to aid my 80 year old mother who has difficulty with the seating position. I figure this will help her keep smoother cadence.

My plan is to use the TongShen TSDZ2 with just the torque sensor, no throttle nor brake sensor. According to auto-ebike https://www.amazon.com/TongSheng-Ve...coaster&qid=1557594084&s=gateway&sr=8-2-fkmr0, they have a version that works with coaster brakes like the Worksman has.

Am I crazy, or would this work? And what other issues might I run into? I need to source parts online, and then build while visiting her this summer, so I have a limited time period and would like to have everything available at once.