Electric chopper trike build journal

[teklektik]

...Kelly Controllers ... provided me with software to configure the controllers into "pure current mode" (aka torque mode) rather than the "speed mode" which is how they come from the factory.
...
Some are under the impression they are "torque mode" ... [What Kelly calls Pure Current Mode]
...
if I had know ahead of time, to have had these controllers programmed at the factory for torque mode. [Pure Current Mode]

An important note about nomenclature:
Kelly uses different terminology for modes (at least for this controller) than is commonly used here on ES. This is a source of great confusion not only here but in communications with Kelly and perhaps their vendors (QS Motors in this case). For instance, in the OP's account above the term 'torque mode' can convey something entirely different depending on who is listening.

From the OP's other thread on Bad Controller Behavior:

...the KLS-S can be ordered with one of three control modes. The Kelly mode names in bold/undeline are slightly different than commonly used here on ES:

1. Torque Mode - this is open loop PWM mode - fast response, no feedback loop, rpm+torque not directly related to throttle setting
2. Pure Current Mode - closed loop mode where the phase current is directly proportional to throttle voltage. This is the same as a Phaserunner and is often referred to as 'Torque' mode because torque is directly proportion to phase current and so the throttle directly controls torque.
3. Speed Mode - a closed loop mode where rpm is proportional to throttle voltage.

So - just to be clear for folks pursuing similar builds - the proper controller mode to order is "Pure Current Mode" not "Torque Mode". This is using Kelly's nomenclature and will get you what you need to replicate this project.

Anyhow - closeups of the interesting build details have been great, but hoping for some shots of the whole trike - quite an inventive and impressive project!

 

[cboy]

Some photos of the finished trike, running and on the road.

 

[cboy]

And a video showing the Cliff Notes version of the build and the chopper trike out for a spin.

https://www.youtube.com/watch?v=QwWzzDFrNT8

 

[teklektik]

Good video and photos!
This looks like it's working pretty slick.

How's the handling and suspension working out? There were posts at the beginning about the relatively short swing arms and the rearward center of mass. I'm curious also about the front suspension stiffness without the engine weight.

 

[cboy]

How's the handling and suspension working out? There were posts at the beginning about the relatively short swing arms and the rearward center of mass. I'm curious also about the front suspension stiffness without the engine weight.

The rearward center of mass now has some actual numbers attached. I put the finished trike on a scale and the weight on the rear wheels is 706 lbs. and the weight on the front wheel is 117 lbs. That means the front springs and shocks are carrying about 266 lbs LESS than they did with the stock Voyager bike (Voyager curb weight is 765 lbs and I'm estimating a 50/50 weight distribution). This also means the rear springs and shocks off the Voyager are carrying 324 lbs MORE than they were on the Voyager...not including a rider or passenger.

Ride wise, the rear feels very good. The rear sits on Progressive coil over shock which are after-market units which came with the donor bike. I currently have them set at their softest spring tension rate so I have room to stiffen the rear up if the extra weight seems to be a problem, which thus far it has not. One thing that may be helping me out is that I am a relatively light weight rider (160 lbs) and the trike is not equipped to carry a passenger. The Voyager, on the other hand, is fully capable of carrying a 250 lbs rider as well as a good sized passenger. So my curb weight on the rear is much higher but my "fully loaded" weight is probably about the same as what the Voyager is expected to carry while maintaining a comfortable ride.

The front end was a totally different story. The stock configuration of the front fork was far too stiff with so much less weight on it. In addition, the original Voyager shocks/springs seemed to be hanging up a bit (like crud had built up inside them) and the ride was far from ideal. Fortunately, the donor bike came with a rebuilt set of fork tubes. The other fortunate thing is that Voyagers came from the factory with "air-ride" adjustable front springs/shocks. So I have now put on the rebuild set of fork tubes and I have replaced all the Voyager air hoses and apparatus (a LOT of extraneous stuff) with a simple 8M x 1 Shrader valve screwed directly into the "fill collar" at the top of the fork. I also replaced the oil in the shocks with 5W and purposely did not completely fill the oil to its normal level. At the moment I am running no air at all in the shocks and they are responding far better than the original units. I still need to get some additional test miles under different road conditions and head for some streets where I know I'll encounter potholes and rough going. But I think the front is now getting close and I have the ability to fine tune from here on out by just adjusting the pressures in the air ride system.

I'll report back more on the suspension and performance as I gather some useful numbers.

 

[teklektik]

Interesting stuff.
Thanks for the continuing story and evaluation...

BTW - how's the body roll. Normally not a queston, but your battery pack doesn't seem to have a lot of ground clearance.... This may not be an issue at all, but if so, perhaps a sway bar would be helpful. Sort of an odd thought for a trike, but...

 

[amberwolf]

How is the trike working out now?

 

[cboy]

How is the trike working out now?

The only tinkering I'm still not completely satisfied with is the front suspension. The rear seems fine to me...little if any body roll (although I'm not doing any dare-devil cornering) and the progressive coil over shocks take bumps and potholes with ease. The front fork, however, is a different story. This is a fork designed to handle a curb weight in the neighborhood of 400 - 425 lbs (from a Kawasaki Voyager 1200) and it is currently carrying well under 200 lbs. Even with the 5W oil I'm using, the front doesn't not seem soft enough for me. Ironically, Voyager owners usually hate this front suspension because it is TOO soft. As a result there are no aftermarket springs which are softer, only stiffer. About the only other alternative I can see is to try to find softer springs from another, lighter weight bike which would fit in the Voyager fork tubes. But that may prove to be a difficult search.

At the moment, however, we are into the cold and rainy season here in the Central Valley so less riding time over the next couple months (you can count me in as a fair weather rider). In addition, I'm currently in the middle of my next project...a "scrap parts" go cart (ICE motor so a no-no for this forum) I'm building with and for my 10 year old granddaughter as a Christmas present. This thing is sort of like Frankenstein's monster...made up from a variety of parts and pieces from an old 5 horse Murray snow blower, a couple of junked bicycles and a discarded mobility scooter. I've already built her an electric trike (500 watt mid-mount) but childhood wouldn't be complete without a quick and loud go cart.

 

[SlowCo]

Great to read that the trike is doing well.
Regarding the front fork being too stiff for this application. You could try and run only one spring and leave out the second one. And also only fill one (the other side) fork tube with oil for the damping. Many bicycle MTB forks work like that. And also some motorcycle forks:
https://www.showa1.com/en/product/motorcycle/detail_shock_absorber_f_sff.html?width=740&height=530
Then you are able by increasing oil thickness and level to increase the damping to the desired amount. And by using spacers on the spring to give it the correct preload. If the spring rate is too low you could try and find one uprated stiffer spring made for that fork. Good luck improving the trike and enjoy building the go cart (some photo's of that smuggled into this thread are appreciated... :wink: )

 

[cboy]

You could try and run only one spring and leave out the second one. And also only fill one (the other side) fork tube with oil for the damping. Many bicycle MTB forks work like that. And also some motorcycle forks:

Thanks a heap SlowCo. Sounds like a great option to try out. And I would have never thought of it on my own. Just another tribute to sites like E-S that allow us all to become a little smarter just by just listening to one another. One added benefit to this potential solution is that the Voyager fork has air ride...so I might be able to balance things out by adjusting the air pressure, oil weight and/or oil fill levels.

 

[SlowCo]

:thumb:
I love simple, cheap and effective solutions so I hope it will work out for you!
And as I wrote: try to sneak a few pictures of the loud gasser go kart into this thread when its finished.

 

[cboy]

... try to sneak a few pictures of the loud gasser go kart into this thread when its finished.

I'll probably post a short build journal of the gasser go kart on my web site and also do an Instructable for it. A couple of those photos could mistakenly get posted up here.