Leaning E-Delta Trike Idea

[LI-ghtcycle]

Ok, so I have an idea that just occurred to me when seeing someone else's pursuit of a design in which to build a leaning delta trike.

The biggest objection I have for most delta style trikes, is they either have one rear wheel powering them, or the front wheel, neither are ideal.

I have come upon a solution in my mind to this issue, and I want to brain storm with you all, please feel free to poke holes in my plan.

To avoid the problem of one rear wheel powering the vehicle, and an overly complex rear differential like you have in a car, I propose 2 rear hub motors in 20" wheels in a similar style leaning mechanism to this Varna bicycle:

(Video download second from top)

http://www.varnahandcycles.com/video.htm#hc16

The pros are pretty obvious to me, simple construction, uses a snowmobile style torsion bar in the middle "boom" section so that the front half of the bicycle leans letting the rear wheels stay in contact with the ground.

Cons? Perhaps in my incarnation the extra weight and known disadvantages of hub motors in general, however, I would propose to use two of John in CR's scooter hub motor's in 20" mag wheels (scooter/motorcycle wheels that will bolt to the flanges of the motors as they are designed) thus eliminating some of the potential down sides of heavier hub motors when using bicycle wheels & spokes (sure this will weigh more, but no issues with spoke maintenance and limitless cargo capacity compared to bicycle components).

I would have my design perhaps a little lower to the ground, more in-line with the height of my Vision R-40's seat hight, so it will be a bit lower than the design of the Varna that seems to be build more with ease of riding and use than aerodynamics.

This would allow for a higher seat position and less compromise needed to get much the same aero advantages when covered with a Velomobile shell with out the lower seat that you have to slip into, instead it can be a flip-up style monocoque shell much like the popular Lietra Velos:

And I would design the shell closer to the style of this other leaning trike, but with a roof with maximum visibility and maybe a very narrow windshield instead of a bubble:

(this is the style of roof I would want on top)

In fact, here is a Delta Velo from Velomobiles.ca that is very close to how I would design the shell:

Might adjust it a bit since mine wouldn't be so low to the ground.

Thoughts?

Thanks!

 

[John in CR]

You don't know how many time I've thought of doing almost exactly that, though my thought process is why stop and 2 and not go AWD.

I've also got a differential that includes the axle and is beefy enough to be almost the entire structure for the rear, since one of my larger motors is plenty to give such a light vehicle real press you into your seat acceleration.

I'm not 100% sure about any hubmotor meant for a 2 wheeler being used on a non-leaner. I worry about the side loads on bearings not meant to take side loads. The bearings on the MiniMonster may be large enough that there's a tapered bearing that's a drop in fit, and make the motor capable of side loads.

John

 

[LI-ghtcycle]

You don't know how many time I've thought of doing almost exactly that, though my thought process is why stop and 2 and not go AWD.

I've also got a differential that includes the axle and is beefy enough to be almost the entire structure for the rear, since one of my larger motors is plenty to give such a light vehicle real press you into your seat acceleration.

I'm not 100% sure about any hubmotor meant for a 2 wheeler being used on a non-leaner. I worry about the side loads on bearings not meant to take side loads. The bearings on the MiniMonster may be large enough that there's a tapered bearing that's a drop in fit, and make the motor capable of side loads.

John

I like the AWD idea too! And I agree, Why not!

Good point, I haven't thought of that, but what about if you had a slight camber on the rear wheels so they aren't taking side loads?

Here in the video the video below you can see what I mean:

[youtube]eeFUvBDNhRw[/youtube]

 

[Sancho's Horse]

I learned a few things about trike strategies. 1. Don't tell people in a motorcylce forum that you are building an electric trike 2. A live axle is much cheaper, is nearly indestructable, and works fine (not as good as the IRS they all use now, and less low speed fine control)...but there is a much greater premium on front end geometry

Ok, I guess I learned two things.

Not a lot of experience in this area, but love to hear opinions.

*Glad I spend more time on this forum.

I think the tilting mechanism on the varna is a good one, and seems eminently replicable. I wish I had the time and technical expertise to do it.

I saw your other thread on velos, and I especially like the use of a convertible fabric top. I don't particularly like working with fiberglass, but getting the right seating position, and the flip-up shell seems like it would be worth it. Plus the aero...you could either save batteries, go faster, or a bit of both. Huge time commital, but getting the frame right seems like it could have paybacks long after the batteries are toast.

 

[LI-ghtcycle]

I learned a few things about trike strategies. 1. Don't tell people in a motorcylce forum that you are building an electric trike 2. A live axle is much cheaper, is nearly indestructable, and works fine (not as good as the IRS they all use now, and less low speed fine control)...but there is a much greater premium on front end geometry

Ok, I guess I learned two things.

Not a lot of experience in this area, but love to hear opinions.

Live axle's only issues are going to be when cornering, and two rear hub motors will have the same problems I suppose, since both will want to go the same speed in a turn when the outside wheel will cover more ground than the inside wheel, thus causing the wheel on the inside to "chirp" since it needs to loose traction to make up for this, so maybe I should look at this lightweight high-strength rear diff that you're talking about John, I'm guessing it's more than the typical one you see listed as an add-on to rear drop-outs of a standard 26in MTB?

Perhaps I will get away with it with 2 hub motors since they aren't exactly linked together like a live axle, or maybe I would be better off with just one hub in the back one in the front and let one rear wheel freewheel?

Not ideal, but certainly less issues I imagine, less to worry about making work properly.

 

[ddk]

of the two delta trikes I own, both with front/rear drive (but one uses a limited-slip differential while the other uses a live axle) handling is about the same as is power/acceleration.

Neither trike tilts and I actually see no need for that feature, as they are both semi-recumbent and both handle turns much better than any sit-up-high delta trike.
Just a thought...

 

[John in CR]

w Hubmotors will act like a perfect limited slip differential and nothing like a fixed axle with one wheel chirping.

 

[amberwolf]

I doubt there'd be much problem with two hubs in the rear. Perhaps any problems with differential issues could be solved if you use geared hubs that freewheel internally. (though I am not sure that would matter).


I think it's in my Delta Tripper thread, or the similarly-dated CrazyBike2 posts, but I had a pondering about tliting just the front of the trike from teh seat forward. It'd have a pivot plate between the regular "bike like" front half and the trike kit rear section, and probably use some pneumatic lifters I have between the trike kit sides and the bike stays or seatpost so that it would help re-self-center the front upright, but allow me to force it over with my weigth as I lean in turns.

The main problem I foresaw was chain twist between pedals and input to the trike section, and pondered using a driveshaft centered on the pivot to transmit from front to back of trike, and chains from pedals to shaft and shaft to axle/wheel.

Like usual I got pulled away from the project so I havent' ever tested the theory,b ut I would definitely like to.

Recently I had gotten the trike bits out while searching for otehr things, and have been considering putting it together at least as a basic trike, using the newer Fusin geared hub on the rear, but I have not had time tod o anythng with it yet. I am off for the second week in January and hope to at least touch it a bti after I get done with other things I already promised people would be done long before now. :/


My plan ahd originally been to use two of the older small Fusin geared hubs--one in the rear rigth on the "undriven" wheel in my trike kit, and one in the chainline from the pedals that could drive the bike thru the 3speed IGH in the left wheel. The one in the wheel itself would only be used for extra power and for backup in cse of drivetrain failure, and the one in chainline used to ekep efficency higher.

 

[Sancho's Horse]

ddk - did you watch the varna video...especially going up the uneven hill. I really don't think a non-leaning trike could have such a small turning radius...or, notice how the leaning mechanism acts as a suspension on uneven ground. Going over that would be a tipping nightmare ona trike with my geometry.

I don't think I would notice wheel chirping, because turning at wheel chirping speeds means I would be more focused on tipping. My trike is a bit more like a rocket than a fighter jet.

There is a fairly cheap go-kart differential I considered using. I may still try it in the future. My set-up will go hub motor...to nuvinci n171...to jackshaft, and I was thinking freewheels to either side of the differential possibly in the future. I am leaving the bottom jackshaft extra wide just for this purpose. My cranks are going to bypass the nuvinci and go straight to the rear axle. I feel like I can supply power where it is needed, more intelligently than the nuvinci, and at faster speeds my pedalling will be less effective anyways. This will allow me to remove the drivetrain and just use it as a regular pedal powered trike when the need strikes.

 

[LI-ghtcycle]

of the two delta trikes I own, both with front/rear drive (but one uses a limited-slip differential while the other uses a live axle) handling is about the same as is power/acceleration.

Neither trike tilts and I actually see no need for that feature, as they are both semi-recumbent and both handle turns much better than any sit-up-high delta trike.
Just a thought...

Yeah, the main reason is I want my cake and eat it too!

I want a more up-right trike that handles corners at faster speeds, not wanting to be as up-right as say a Schwinn Meridian, but somewhere in between, the Varna appears to have the height I am looking for.

 

[LI-ghtcycle]

w Hubmotors will act like a perfect limited slip differential and nothing like a fixed axle with one wheel chirping.

Kewl, I was hoping this would be the case!

 

[amberwolf]

It's not leanign (yet) but this is the thread for delta tripper, latest post.
http://www.endless-sphere.com/forums/viewtopic.php?p=681469#p681469

 

[ddk]

Yeah, the main reason is I want my cake and eat it too!

I want a more up-right trike that handles corners at faster speeds, not wanting to be as up-right as say a Schwinn Meridian, but somewhere in between, the Varna appears to have the height I am looking for.

my trikes sit me up at the same height as a passenger car.
However, I do note your interest in having a full fairing and in that case a leaning trike would be the better choice.
By habit, not necessarily need, I always lean my upper body into curves above 10mph and have taken road (lane) curves greater than 90 degrees at my full speed of 20mph without tipping.
I know the point(s) where the trikes tip (By stupid testing) (stupid because I could have hurt myself badly)

@Sancho's Horse... I've no doubt a tilting trike would perform better than my trikes, but I don't require that level of performance where the suspension systems I do have perform adequately at the speeds I usually travel (which is slower than the average ES board member)