The MOTIVE 70CC WHEELCHAIR
FAST AND FURIOUS
By Matt Cuddy
For some of us, a spinal cord injury has taken away our ability to walk, and without extreme modifications, our ability to ride a motorcycle. After the major trauma of a spinal cord injury, riding a motorcycle is usually not very high on the list of things to shoot for, and soon the idea’s forgotten about, and more pressing things like figuring out how to work the stove again, or put on your pants takes up most of your spare time.
But there is hope for the obsessed downed biker, who misses the wind in his hair, the smell of the exhaust, and the freedom a bike once gave him.
And it’s called the Motive Wheelchair kit.
WHAT IS IT?
The Motive kit is the brainchild of Chris, Cary & Craig of Motive Transportation LLC, based in Wisconsin, and is sold in kit form to fit on the Invacare A4 lightweight rigid frame wheelchair. All the parts in the kit allow you to transform a regular hand-powered wheelchair, into a controllable, stable and fun machine that allows the wheelchair bound operator to get “in the wind” again. The only things missing in the kit are the motor, a few ignition parts, the battery and the ability to assemble one.
The chair in a hoist so I can work on it...
You can choose a fifty cc motor, a seventy cc one, or a one hundred ten cc motor all clone Honda designs, manufactured by several companies in China. All the motors posses an electric start and the rugged build quality of an older Honda motor, which makes them pretty indestructible, if you get a good one. Mine had a few “quirks” that had to be addressed before any real riding could be accomplished. For instance:
The motor started leaking oil out of the dry case on the alternator side, so I ordered a new crank seal, and was about to yank the motor out, when I decided to check the crankcase breather tube, just for the heck of it, to see if it was kinked or pinched. What I found was a No.2 pencil stuffed into the breather tube, effectively causing the crankcase to build up enough pressure to cause the crank seal to pop out, and blow oil everywhere. Upon removing the pencil, the oil leak lessened, and now I have to take it apart and put the seal back in. Clever those Chinese and their little jokes on us occidentals. Must have been that Boxer rebellion thing or something. And yes, it was a Chinese pencil.
Rotten excuse for a carburetor...the venturi is a joke.
Then there is the carburetor. A Kehin knock-off, it worked just fine for a few weeks, then the float started sticking, and it started peeing gas out the overflow line, making me a candidate for the Buddhist self-immolation club. After taking the damn thing apart about fifteen times, I bent the float tab down to super-lean, and turned the wire needle holder around. That didn’t do a damn thing, so I ordered a new carb, a Japanese Kehin this time. The Chinese one makes a worn-out Spanish Amal look like a rocket science. Crap city. I received and installed the replacement 17mm Kehin, and it made a big different in performance and starting. The exhaust system is noting to write home about, so again, it’s getting replaced with dual 28 inch fish tail units from a Sportster. Won ‘em on ebay for twenty five bucks. Love that ebay.
Booo, bad carb...
With the standard ¼ gallon gas tank, the Motive 70cc has a range of about twenty miles. And I must point out yet another potential for trouble. The gas line and flimsy gas petcock aren’t hose-clamped to the tank or the gas line, and more than a few times when turning off the gas, I removed the entire gas line from the tank and valve, and had gas shoot out like from a fire hose on the garage floor. One spark and we would have gone up like the Hindenburg.
I’m replacing the gas tank and gas petcock with half-gallon spun aluminum Coyote Engineering unit and brass/stainless steel petcock. Looks trick, is trick.
Sano 70cc Honda clone motor manufactured by LIFAN China
WHERE I GOT IT
I purchased mine used and fully assembled from a guy in Pennsylvania who’s right wrist went down the tubes on him, and he couldn’t operate the throttle anymore. So through the Motive people I got in contact with Chuck Depara who sold me the entire rig for an excellent price, plus shipping. Chuck was injured in a lathe accident aboard an off-shore oil rig, and it messed him up pretty badly. But not bad enough to be able to assemble and ride a Motive. I wish Chuck the best in his recovery. Chuck is just another biker/hotrod nut that had some bad luck and refused to give up. Bravo Chuck.
Nice diamond plate alumimum foot plate
BOSS! THE CRATE!
After receiving the crated wheelchair (that was sent in a crate strong enough to survive a moon shot) I started to re-assemble the wheelchair, and in about half a day had it together again and running. One thing that bothered me was that both steering levers stuck straight up on either side of the seat, and it made transferring to and from the chair a colossal pain in the ass (literally). After falling on said ass a few times exiting the machine, I decided a modification must be made, to allow the left steering control lever to break-down, so I could slide in from the left side, without rear of falling.
My good friend and fabricator Al Lombardo was put to task modifying the left steering control arm, and now mounting the chair is no problem, and can be done alone, without fear of falling. A real important safety item for paralyzed people like myself. We cut the arm right below the seat, added a flange, and a pin with two detent-balls that goes through the flange and brake plate. Works perfect.
A quick-release device for left steering lever, that allows for an easy transfer on and off the chair.
Remove the pin and the top of the lever slides out.
And the lever folds down to allow a clean transfer
Also, the Invacare Ti A4 that I got had a non-adjustable foot plate that put my knees up around my ears, so that got modified too. We had to build a new sub-frame for the foot-plate that dropped it down about two inches, and tightened up the frame as well. We constructed the new foot plate out of 1/8th inch aluminum diamond plate, with a 2 inch border that protects your feet, and keeps them from sliding off into the street. Chuck commented that we could also use the foot plate as a BBQ, but we dismissed that idea since the chair is gas powered, and we don’t want any explosions ruining our fun.
OOPS, FORGOT THE DAMN BRAKES…
One of the most important things a wheelchair needs was overlooked in the kit though, and that is a parking brake. It’s almost impossible for someone who’s paralyzed to make a safe transfer from one chair to another if the “other” chair is devoid of a parking brake.
We fixed this on a temp basis by making some wheel-chocks like an airplane uses, but this should have been thought out by the kit maker. I made the transfer several times from a chair that has a lower seat height, and it was real difficult without a parking brake on the Invacare A4. So the wife found a place named D’s Locks that produces a trick parking brake assembly that’s getting purchased and installed next week. A very important part of the chair.
Also overlooked were wheel guards to protect your upper thighs from the spinning wheels. For someone who has no feeling below the waist, that's another very important item missed. Again, we had to purchase some clamps and garment guards from Invacare to protect the old thighs. We haven’t received the clamps yet, so they didn’t make the test.
I'm not saying it’s the fault of the Motive folks, but it would have been nice to have those parts in the kit too. Seems Motive concerned themselves with just the drive train, and left the wheelchair configuration up to the rider/user.
Build quality of the kit is impressive, and you can see major thought went into producing a reliable assembly that could withstand the rigors of both on and off-road operation. The whole assembly, the engine and primary drive to the wheels is suspended underneath the Invacare A4 in a sub-frame, and is allowed to hang loose, with the two steering levers being major points of connection to the frame of the wheelchair. Inside the long sheet metal assembly are the primary chain, and all the electrics needed to start and run the chair. The two primary drive wheels are supported by a strong 5/8th inch steel axle, held in with some high-quality roller bearings in the drive unit, and at the end of the steering levers. The system looks overbuilt in this area, and should cause no problems for a long time.
Sano engine mount. The whole unit moves to allow the wheels to engage at the selected moment.
With the motor suspended in the sub-frame by springs, this allows the drive wheels of the unit to engage and disengage the main wheels, and allow the chair to turn on a dime. When received from Chuck, the motor was in the sub frame crooked, and sat too low, about an inch off the ground, so we modified a spring off an XL600 Honda kick-stand that got the motor in there straight, and now it has about two inches of ground clearance. A skid plate is in the works.
EVER DRIVE A SHERMAN TANK?
The Motive chair steers like a tank, or Caterpillar tractor. To turn right, the left arm is pushed forward, engaging the drive wheel, while the right arm is pulled back, disengaging the right drive wheel, and the chair turns right, If a hard 90 degree turn is required, the right lever is pulled back hard enough to engage the brake, which allows the chair to pivot, and make the 90 degree turn. Pretty ingenious, and the machine is very stable when going in straight line too, despite the shortness of the unit (like my old Buell City-X). More on the handling later.
When the restrictor plate was removed from the intake manifold, and the REAL Kehin carb installed, top speed is around 30 MPH, making this one fast wheelchair. I was timed by my buddy Al in his VW, and a sustained speed of twenty miles an hour felt real safe and stable. The machine has a horn button on the left steering lever handgrip (on top), and the e-start button and kill button on the right side steering lever. The kill button is on top of the throttle grip, is colored red and impossible to miss.
The Motive at about 20 MPH. Lots more left.
WHITE KNUCKLES & GRITTED TEETH
So let’s get this little beasty fired up, and out on the road. First, you switch on the power with a key mounted in the front of the transmission case, and the green light goes on, indicating you have juice. The starter button is mounted on the throttle side, underneath the throttle assembly, and the 12v system cranks the motor over nicely.
Almost topped out at 30 MPH. Real stable at this speed.
Like most Honda motors, the unit is very cold blooded, and needs the choke for about 1-2 minutes while the motor warms up. Reaching back, the choke is disengaged, and blipping the throttle a few times tells you that, yes indeed, there’s a Honda motor down there underneath you somewhere. A few quick glances around you to make sure your feet are in the foot-plate, no loose clothing is hanging down by the drive wheels, and you’re ready to move out.
Transferring from an Invacare Top End to the A-4. Tricky business without a brake on the Motive.
By pushing forward on the steering levers, the two drive wheels engage the main 24 inch wheels, and you start moving. The amount of pressure you exert (up to a point of course) determines how much power gets to the driven wheelchair wheels. Again, turning is kind of intuitive, pull back on the right lever, and push forward on the left lever to make a right hand turn, and just the opposite to make a left. As mentioned before, the chair is very maneuverable at slow speeds, and tight corners, even spinning doughnuts is simple. It’s when you get up to speed is when things get…err…tricky.
Ground control to Major Tom...
So now you’re tooling down the driveway about to merge onto the street. The Motive people suggest you do a wheelie over any expansion joints or other irregularities on the street, to protect the relatively fragile front casters. In fact, riding on the wheelie bars is encouraged. Something I could not get use to by the way. Call me a Luddite. So now you’re in the street, and have made a right hand turn. The throttle is gradually increased, and the chair moves out at a nice pace.
Dig that classic headlight...
It takes a while to get use to handling the chair at speeds above ten miles an hour, as the short wheelbase and the relatively quick steering from the two levers can get you into trouble quick. But if you think it out, and go slow for a the first dozen or so times in the Motive chair, the steering becomes intuitive, and with enough time behind the levers (?) you get some muscle memory going for you, and instead of white knuckling the grips, you can relax and enjoy putting along in your gas powered wheelchair. Slight pressure changes on the levers keep the chair going in a straight line, and mastering the steering of the Motive gave me (at least) a feeling of accomplishment. Like the first time you ever rode a motorcycle, and didn’t fall over at every intersection.
The Motive chair got put to the test in wet weather, and while it did manage to move under its own power once the drive wheels dried out some, water had a negative effect on the machine when going up a ramp, or starting from a dead stop. Also, the braking power was cut by at least 80%, and judging by the two holes drilled in the brake flanges mounted on the steering levers, some sort of brake material will make its way there soon enough, improving the braking situation greatly, as when wet it stops like an old Bultaco with brake shoes soaked in liquid wrench. Not good.
I can’t imagine what mud or snow would do to the forward motion, but I think a set of better tires with less (not more) tread would improve the contact patch between the drive and driven wheels somewhat, and get things moving along better in wet weather. I was also thinking of making some grooves in the drive wheels that would allow for better traction, but being this is Southern California, wet weather is far and few between. So I’m looking around for some better tires with less tread on ‘em.
At speed once again, the compression braking is impressive.
BUT WHO WILL BUY ONE?
This machine is perfect for someone like me, an ex-motorcycle mechanic and racer, who can design and fabricate parts that make the Motive more livable and easier to operate, and has at his disposal a full machine shop with a lathe, welders and drill presses of every sort (and friends who can use ‘em ).
But for someone with less mechanical experience, with little or no background in fabrication and design, I can’t see this kit being used for very long, before the operator eats it big, or gets disgusted with the all the unfinished business and sells it to the highest bidder.
It’s like a kit-car, you get the basics, and have to finish up the items that were missed in the original kit's design, and tailor it to your specs. Something I like doing, thankfully.
The Motive chair produces big grins, and was a perfect vehicle for me to get back into wrenching and bolting stuff together again. For someone who had several projects going at the same time, and who lived in the garage, this has been great therapy, and got me out of the blues real quick. This kit isn’t for everybody, but like I said, for the downed biker or hot rod freak who wants something unusual and eye catching, Chris and his buddies have put together something magical.
It will be in my garage for a very long time and with all the hop-up parts available for the mighty Honda 70 motor, maybe a special class at Bonneville? I can see the bubble fairing now…
THE ROCKET SLED. SEX ON WHEELS...
That about sums it up, it’s not for everybody, but it is for people who aren’t afraid of something different, and a little dangerous. Like a nice fast motorcycle.
And that’s motive enough.
UPDATE ON THE WHEELCHAIR 12-24-10: Got some "Frog Legs" front forks for the Invacare, man, they really work! A full 4/16th of an inch of travel!
Here's a few pics. The Frog Leg prople are great, modified some crap I bought off EBAY into workable units for free.
Pretty darn trick, eh?