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Discussion Starter #1
Hello,

My name is Dan, I'm a disabled/retired mechanical engineer

Last year I built an electric go kart to autocross using a Rotax RM1 kart chassis with 7, 20 AH lead acid batteies, a D&D SepEx 32A-50 motor and a 425 amp SevCon controller.

I was competitive with the 2 stroke karts even though I ran 100 lbs over the minimum class weight. I pulled very close to 400 amps at 84 volts and topped out over 55 mph

\I'm now building a reverse trike for the street from the ground up. It uses 1 inch 16 ga tubing triangulated with .050 aluminum sheet bonded to and riveted. (Think Lotus 7 construction) The front suspension is custom made with Fiero uprights and brakes, fiero steering rack, and custom made 4130 tube unequal length A arms, Carrera coil over shocks.

I'm using seven 185AH lead acid batteries. five of the batteries run down the cockpit's tunnel, between the seats. One is in front of the cockpit, the other behind. Bolted behind this cockpit is a 1983 Kawasaki GPZ 750 frame, swingarm and suspension.

I'm working on the body now, it is foam core with fiberglass and epoxy resin.

It's registered and insured but not inspected. The local bike shops are unsure what to do with it here in Maine. I have driven it a bit nd it will cruise at 55 mph. Based on my cycle analyst gage etc.. it looks like 50 miles will be a usuable range on secondary roads.

The aluminum clad chassis is very noisy since the motor etc... doesn't make much noise. I've got tons of looks wherever I go with it. I'll be adding an MP3 stereo soon.

It weighs 1105 lbs empty, I'm trying to work out the spring rates etc...
I could use narrower front tires, the 195-60-14 Falken azenas have too much drag. The std motorcycle rear tire holds the road very well.

I'll get some photo links soon
 

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Sounds awesome I'll look forward to some pics. How about some pics of your kart, too?
Hello,

My name is Dan, I'm a disabled/retired mechanical engineer

Last year I built an electric go kart to autocross using a Rotax RM1 kart chassis with 7, 20 AH lead acid batteies, a D&D SepEx 32A-50 motor and a 425 amp SevCon controller.

I was competitive with the 2 stroke karts even though I ran 100 lbs over the minimum class weight. I pulled very close to 400 amps at 84 volts and topped out over 55 mph

\I'm now building a reverse trike for the street from the ground up. It uses 1 inch 16 ga tubing triangulated with .050 aluminum sheet bonded to and riveted. (Think Lotus 7 construction) The front suspension is custom made with Fiero uprights and brakes, fiero steering rack, and custom made 4130 tube unequal length A arms, Carrera coil over shocks.

I'm using seven 185AH lead acid batteries. five of the batteries run down the cockpit's tunnel, between the seats. One is in front of the cockpit, the other behind. Bolted behind this cockpit is a 1983 Kawasaki GPZ 750 frame, swingarm and suspension.

I'm working on the body now, it is foam core with fiberglass and epoxy resin.

It's registered and insured but not inspected. The local bike shops are unsure what to do with it here in Maine. I have driven it a bit nd it will cruise at 55 mph. Based on my cycle analyst gage etc.. it looks like 50 miles will be a usuable range on secondary roads.

The aluminum clad chassis is very noisy since the motor etc... doesn't make much noise. I've got tons of looks wherever I go with it. I'll be adding an MP3 stereo soon.

It weighs 1105 lbs empty, I'm trying to work out the spring rates etc...
I could use narrower front tires, the 195-60-14 Falken azenas have too much drag. The std motorcycle rear tire holds the road very well.

I'll get some photo links soon
 

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Discussion Starter #5
I need to bring it to the local CanAm dealer... problem is I can't drive it there and drive home, It's marginal range wise! They are prepared to check the front end etc.. although it's all new race car capable parts for much heavier vehicles etc...

I do have access to an enclosed trailer to bring it there...

I'm not happy with the suspension of the trike as it sits... hard cornering can cause slight rubbing of the front tires vs the bodywork. I ended up using heavier batteries than I originally intended and did the first few runs with a 72 volt pack vs the 84 volt pack.

I've ordered heavier rate springs and should be in a better position with it late next week, I've also started designing a sway bar for it

I've added some foam seal material to the aluminum inner fenders too to get another 3/4 inch clearance and if need be I'll go to slightly smaller tires and gain another 1/2 inch

I hope to mold up the suicide scissor doors this winter. Think lambo door pivoting at the roll bar behind the seats. I'll also add lightweight body panels to complete the teardrop shape later.
 

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I'm not happy with the suspension of the trike as it sits... hard cornering can cause slight rubbing of the front tires vs the bodywork.
I'm glad you brought that up.
I noticed in your photos that the top and bottom mounts of your coil over dampers are very close to aligning with the inner pivot of the upper wishbone and the outer ball joint of the lower wishbone.
That sort of set up tends to result in an overall reducing spring rate as the wishbone moves upwards. As the suspension is compressed it gets progressively softer, or fails to get progressively firmer.

If you move the top mount further outwards so the spring is more upright then that will help to stiffen it up.

Try that, even with a temporary, but good, mount and see before you try harder springs and get into the antiroll bar fabrication.
 

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Discussion Starter #7
They are not as close as they appear but yes the angle does increase several degrees casuing a slight reduction of spring rate...

My problem is that I bought the springs and shocks 20 years ago when I started the project. It used the V65 Magna that is seen behind the earlier shots of the frame with my teenage son in them.... The bike powered version will have a huge difference in weight and distribution of the weight. I mocked it up to try with what I had...

I was diagnosed with MS in July of 1991, I have a bunch of neurological issues and didn't take up the project again until my teenage son had interest. He worked on the bodywork as his senior project in HS. Now he is in his 1st year of college for biomedical engineering.

Seven 12v, 185 amp hour pb batteries are very heavy, they make up almost 1/2 the weight of the trike. (500 lbs) Also the reverse trike arrangement has less roll resistnce than a normal car because resistance to roll is performed by only the front wheels, the trike rotates around the rear wheel.
\
Hopefully I'll get it stickered this fall. It's getting pretty cold up here and it's hunting season so I have limited time to work on it
 
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