# Lightweight Commuter Trike



## Inquisitor720 (Aug 15, 2012)

Hi all. This is my first post. On other forums, senior posters tend to get a little peeved with new timers like myself, but seriously, I’ve tried searching around on the forum for the things I want. I’ve also searched the Internet and eBay profusely. And I’m having troubles finding the next component in my project. I’ve been skimming my way through the “Custom monocoque trike” project, but my project is a little different. I also don’t know if this forum frowns on side questions (hijacking) to someone else’s thread, so I’ve started this one.

Basically, I’m working on a tricycle design that is more closely in concept to the bugev.net trike. I want mine to be in the same weight class as it. It only has to have about a 15 mile range with a top speed of around 45 mph and an average usually far less. I plan on making it more streamlined than the Bug-E and hope that I can achieve these goals with a small motor. Now, for the first question. 

*Wheels and Drive Train*
I want to do a chain drive to the single rear wheel. I’m sure that bicycle wheels can’t handle the lateral loads. And, I really don’t want to go all the way to car tires. By the time I get hubs and brakes and some gear train, I’d be looking at over a hundred pounds. Even motorcycle type wheels, hubs, brakes, sprockets and chains seems way overkill and too heavy. So I started looking at the small (12”) gas scooter wheels. Something like this…









But this seems too light weight. The thin wheel webs aren't designed to take lateral loads and they don't seem like they would stand up to the loads over time. Am I being too conservative or does someone have any recommendations for products and/or vendors for basically the pieces (wheel, tire, axle, bearing, sprocket and possibly brakes) in a size that seems appropriate? Also, what gage of sprockets and chain should I be using for an ~4hp motor (#25, #35 or #40)?


Thanks for your help.


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## MalcolmB (Jun 10, 2008)

Hi Inquisitor

I've thought about building something along the same lines, though a little more powerful. Finding suitable wheels isn't easy and I've looked at all the options you mentioned. Have you looked at spoked supermotard wheels? They're lightweight and well built for off-road use, so should have ample strength for the lateral loads you would get at your low speeds.

If low weight is a high priority I'd suggest 219 chain. It's widely used for karts, so there's a good selection of sprockets available. If you want to go stronger or low-maintenance, 420 or 428 chain and sprockets are widely available.


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## mizlplix (May 1, 2011)

In something this light weight, I would consider a motor/hub/wheel combo. Saves space & weight as well as looking good.

Get at least a 48 volt 800Watt unit.

Are you using a body? Premade or custom?

Miz


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## Duncan (Dec 8, 2008)

Hi Inquisitor

Have you looked at HPV type trikes?

How much weight will you have on the rear wheel?

How about a tandem wheel?

Or a mountain bike wheel that is symmetrically built - not dished 

If you look at the loads on a mountain bike wheel - with a heavy guy off road
I think a light weight trike will be OK


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## Salty9 (Jul 13, 2009)

Have you checked Endless Sphere? http://endless-sphere.com/forums/index.php?sid=f118e9ce37923b3b7ce2e570468844ae


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## Inquisitor720 (Aug 15, 2012)

*Hi All,*

Thank you guys for helping out. I think I should have added that I’m on a relatively tight budget. Also, as I was going over some of your all’s suggestions, I stumbled (and I mean… luckily fell into… the error of my ways). Every search I have done on the forum, on eBay and on the Internet, I used the word scooter, car, bike or motorcycle AND the word *wheel*. I stumbled over the word *rim* instead and a whole new world was presented to me. 

*MalcomB*,
I looked over Google searches with _supermotard wheels_. I found a lot of wheels starting out at $500 and some really cool, lightweight ones at $2600. These were just the rims. The tires start out over $100. The rig in the original posting is $60 which includes the wheel, tire, bearings, sprocket, brake and axle and mounting nuts. If I could get comfortable with its lateral strength, and the strength of the #25 chain it uses, it fits the bill and budget. Also, I would like something that I could mount a car tire with its better contact patch. Kind of like the size tires on your Mini. BTW, I was reading through your project for inspiration and I must say your work is very logical, clean and just plain feels right. How did you work out the issue with the mirrored motors and one having to run reversed? I always thought motors that large could only be run in one direction. Looking at the brushes in one of your pictures, I noticed that they are off centerline. I can imagine that running it backwards might chip the pointy edge of the brush or cause some un desirable behavior.

*Mizlplix*,
Yeah, those units look pretty cool. I’d imagine they’d be quieter than a chain. But again cost is a big issue and I’m not sure the weight would be much lighter. Also, I’m looking at a little more power than they seem to offer. I’ve purchased two motors off eBay. One was $17. Its label indicates that its continuous rating is 1.5 Hp at 95 volts and its peak is 2.65 Hp at 21.4 amps. The second cost me $30 and states it continuous rating is 2.5 Hp at 130 volts and 10 amps. I’m hoping I can get 4Hp or better for short bursts of acceleration. Once I get enough batteries to test them out, I’ll see what they really can deliver. 
As far as a body – it’ll be custom, welded tubular frame with a male molded fiberglass body. 

*Duncan*,
I haven’t in a while, but that’s about the level of framing I’ll be using. But you’re right, they must be able to take some lateral loads and a mountain bike must take a lot of punishment with a 200+ pound guy on it. I plan on making it a two seater (side by side). So I’m guessing around 200 pounds on the rear wheel. I’ve still got batteries to study and do some FEA on the tubular frame so 200’s a real WAG.

*Salty9*
I haven’t but I will now. Thanks.


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## Woodsmith (Jun 5, 2008)

How light weight do you want?
I am trying to figure if you want something that is a heavier and powered version of a HPV (Human Powered Vehicle) or a light weight motorbike based reverse trike.

Have you looked at this hub motor from EnerTrac?

I started off looking at scooter front wheels, like those from the Peugeot Speedflight that are single sided, for the front of my trike but decided to 'go large' and have opted for MGB wire wheels on the front and a Morgan wire wheel on the rear.

I reckon the wheel alone might weigh more then your trike!


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## MalcolmB (Jun 10, 2008)

Yes the supermoto gear is expensive, though you might be able to pick up wheels and tyres on ebay or the like, depending on where you are.

Here's a link to an interesting design by Stuart Mills, a prolific British kit car designer. It uses wheels and tyres from a Suzuki Burgman scooter: http://www.eco-exo.com/eco-exo_kit_2.html I can dig out some more links and photos if you're interested. I think he used small trailer wheels for the prototype, and also made a version with the Peugeot scooter wheels that Woody mentioned.

Thanks for the comments on my Mini, though I think a few people might disagree with you about the logicality of it... I've been told by a couple of people who know their motors that there should be no problem running one of the motors in reverse. The angling of the brushes is simply to increase brush contact area. They run fine on the bench like this and both draw the same current.


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## Inquisitor720 (Aug 15, 2012)

*Woodsmith*,
Light weight – I going as light weight as I can for the price. Meaning I’m not going to go all carbon/epoxy just to save weight. Obviously, most of the weight is going to be the batteries and until I get these motors tested, I can’t really size that for my distance. But I’m taking a WAG here and I’m being way optimistic.
· ~150 lbs for the drive train including batteries
· ~300 lbs for two people
· ~50 lbs for frame
· ~50 lbs for body
· ~100 lbs for 3 wheel/tire/brakes
· ~50 lbs for misc.
So… I'm guessing the wheels and frame can be closer to an HPV than to a motorcycle. 
I checked out the EnerTrac and didn’t know they made hub motors that powerful. But if they don’t show the price on the web site, I’m sure it’s over my budget. 

*MalcolmB*,
The eco-exo link… That’s about *dead-on* for the sizing of the frame components, and wheels I was imagining I would need. The only difference would be a slight stretch and widening for two people… but otherwise that’s it.
On your mini – I’m definitely no expert or well versed in what everyone is doing… but it seems like most designs are hell bent on using 1 motor and wasting tons of energy to turn all that friction of a standard gearbox and/or differential. You’ll have limp home redundancy and probably far better acceleration than the original car.


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## MalcolmB (Jun 10, 2008)

Here are some better photos of the eco-exo frame and front suspension: http://www.locostbuilders.co.uk/viewthread.php?tid=163440


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## Inquisitor720 (Aug 15, 2012)

Interesting!... using the cross over bar to pick up the other end of the bike axle. 

I was hoping to find a real light-weight car's double wishbone suspension. At least the upright, knuckles, disk brakes and axle and weld up my own wishbones if necessary.


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## MalcolmB (Jun 10, 2008)

[


Inquisitor720 said:


> I was hoping to find a real light-weight car's double wishbone suspension. At least the upright, knuckles, disk brakes and axle and weld up my own wishbones if necessary.


Let me know if you find any  I've been looking for something similar for some time. I'd like to have a go at building a tilting trike one day.


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## Inquisitor720 (Aug 15, 2012)

MalcolmB said:


> [
> Let me know if you find any  I've been looking for something similar for some time. I'd like to have a go at building a tilting trike one day.


Well, I'm not sure how heavy you were thinking... but I stumbled over ATV's. They'll be overkill for what I need, but close enough. Some are quite heavy and they take far more abuse than a street car ever will. And there are plenty of people wrecking or getting bored with them. They're getting pretty sophisticated so getting light weight, fully independent suspensions looks pretty easy also. Just doing a search "ATV spindle" on eBay got several hundred hits.


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## TomA (Mar 26, 2009)

You might want to take a look at Doug Malewicki's California Commuter for inspiration. Its still the high water mark for efficient road trikes, 40 years on...

http://www.canosoarus.com/03CalifCommuter/CalCom01.htm

Could be enlarged into a two seater maybe, but either way, its a sound design.


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## sunworksco (Sep 8, 2008)

If you are on a budget , I would buy a tandem bicycle and use an Astroflight.com brushless DC motor with a Castle electronic speed controller.
If your heart is set on a reverse trike, look at the CatTrikes bicycles.
If you can afford to build a heavier trike, you can machine Ducati 1098 design wire wheel Hub centers, use stainless steel spokes with aluminum rims.
I have the Ducati hub design drawings if you can build these wheels. The great thing about these custom wheels is that they can take the lateral forces and also use automotive tires and inexpensive compared to the stock Ducati 1098 wheels.
The wheels are also pin-drive center-lock, nothing better than that.
Denis Palotov can machine the axles, uprights and wheel hubs.


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## Inquisitor720 (Aug 15, 2012)

sunworksco said:


> If you are on a budget , I would buy a tandem bicycle and use an Astrolight brushless DC motor with a Castle electronic speed controller.


Although I already have the motor and controller parts, I am interested in looking at your references. I found the Castle speed controller, but am having troubles finding the Astrolight brushless DC motor. Do you have a link handy?

I have the motor: 2.5 Hp continuous at 130Volts, 10 Amps. I’m hoping to get close to 4.0Hp for short durations. It cost $29 on eBay.

The speed controller, I plan to make my own. I’m going to use either a Netduino or Arduino micro controller for the brains. These can be purchased for as low as $18. And for the power handling, I have the Mosfet capable of handling 200 Volts and 30 Amps for $2. Throw in a few nickels for miscellaneous hardware pieces and a little software programming and I’ll have a power controller. 

If all goes well, using the same microcontroller, I can add
· speedometer and odometer functionality
· engine and battery temperature sensors
· brake regeneration
· pulse battery charging capability
· diagnostics and history data


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## hmincr (Jan 20, 2012)

I am slowly gathering parts for a tilting reverse trike. I find Motorcycle (Ninja) wheels on ebay. Just paid $8.19 for one. No tire, no brake rotor. I HAVE paid as little as $10.00 for 1 with tire and brake rotor. Average prices are around $20.00 across the board.

I also buy Moped wheels and put new tires on, for my E Bicycle-scooter I'm starting. I live on top of a hill, that's an average of 15% incline in 2 miles of distance. 

Down here, in Costa Rica, rules are very lax. We don't even need pedals on an e Bicycle, yet 

Controllers can be found for around $110.00 - $150.00 for high power hub motors from BIG scooters. Again, check E-S forum. 

As stated, there is a LOT of good info on the E-S forum, same as here.


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## Inquisitor720 (Aug 15, 2012)

hmincr said:


> ... I'm starting. I live on top of a hill, that's an average of 15% incline in 2 miles of distance.


 If anyone is in need of regenerative braking... you're it!


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## Salty9 (Jul 13, 2009)

Malcolm's link to Stuart Mills did not work for me. I did find this which might be the same. http://www.vehicle-designer.co.uk/etrike.htm


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## john818 (Aug 1, 2008)

Inquisitor720 said:


> *Woodsmith*
> Light weight – I going as light weight as I can for the price. Meaning I’m not going to go all carbon/epoxy just to save weight. Obviously, most of the weight is going to be the batteries and until I get these motors tested, I can’t really size that for my distance. But I’m taking a WAG here and I’m being way optimistic.
> ~150 lbs for the drive train including batteries
> ~300 lbs for two people
> ...


400 lbs is going to be tough for a 2-seater, especially on a budget. I think the BugE is around there, but it's a single-seater. Looking forward to seeing how this turns out! I'm thinking about doing a trike build myself. Took some time off my planning, but I'm looking into it again.

Don't know how much you know about reverse trike design, but I assume you'll do your research. From what I've heard, a good rule of thumb is to distribute weight so that it's equal on all three tires. Don't know what you're thinking of doing for steering and suspension, but you might want to learn about Ackerman angles and bump steer, although if you don't have significant suspension travel, bump steer probably won't be a problem.

In case you haven't taken Salty9's suggestion yet and checked out Endless Sphere, you'll find lots of info there, although much of it won't be applicable to your build. Most of the info is for bicycles, but they have plenty of pedal/electric hybrid tadpole trikes capable of 40mph or so. They're not legal, since most parts of the US would require that something that fast be registered, and registration would require brake lights, turn signals, DOT tires and such, but you might get some ideas.

By the way, the Enertrac price IS listed. It's $1295. Mark, the owner, doesn't recommend it for non-leaning trike use, but I'm looking into it anyway.


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## Inquisitor (Jun 21, 2008)

john818 said:


> 400 lbs is going to be tough for a 2-seater, especially on a budget. I think the BugE is around there, but it's a single-seater. Looking forward to seeing how this turns out! I'm thinking about doing a trike build myself. Took some time off my planning, but I'm looking into it again.
> 
> Don't know how much you know about reverse trike design, but I assume you'll do your research. From what I've heard, a good rule of thumb is to distribute weight so that it's equal on all three tires. Don't know what you're thinking of doing for steering and suspension, but you might want to learn about Ackerman angles and bump steer, although if you don't have significant suspension travel, bump steer probably won't be a problem.
> 
> ...


Hi John,

My *current* WAG on my budget stands at less than $1295. So… although that Enertrac is real sweet, it would blow out my budget and then the batteries to feed it would double again and then the weight would go up and it would just spiral out of control. I’m getting some of the pieces in here next week and I’ll have a little more meat in my estimate. 

I don’t know anything “specifically” about reverse trike design, but I’ve done a little suspension design and vehicle dynamics in college. No real world so this is a fun science project. That was decades ago. As a baseline, I was planning on getting the CG around 33%, but I have several reasons for going even further forward.

As far as Ackerman and bump steer, I am familiar with those and although I will be double checking them, I suspect the Honda ATV front end, that I have coming has been analyzed to Japan and back a hundred times by experts on bump steer. They probably aren’t quite as worried about Ackerman as I’ll need, so I pay particular attention to their geometry as it effects that.

I plan on opening a new thread to introduce the project, once I get those pieces together and re-work some weight and cost numbers. I’ve started looking through Endless Sphere and most of their design principles are closer to what I’ll be needing for this project. I’ll probably open a project thread there also to get feedback from their members.

Thanks.


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## Inquisitor (Jun 21, 2008)

BTW - I found, I was already a member here  and won't be using this Inquisitor720 login any more.


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## jddcircuit (Mar 18, 2010)

I am not sure if this was already mentioned

http://switchvehicles.com/


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