Coral Snake Cobb Job

[Mr. Gangrene Genes]

Greetings from Kansas City. Please consider this my belated introduction.
I am a hoarder. Come from a long line of hoarders, cars, trucks, lawn mowers, tractors, bicycles, what have you.
While I would like to be able to stay at home all week and tinker, I remain a white-ish collar slave to the MAN.
For the last several years my main summer transportaion was a high mileage 1987 Honda Aero NB50 scooter. Much cheaper than driving since I don't have to pay for parking or as much gasoline, and faster than the Metro bus while running on my schedule.
Last fall it suffered several set backs that caused me to lose faith in it and it got sold for the price of the replacement piston.
Didn't realize how much I would miss it. So I started digging in the war chest to build a motorized bicycle.



A friend gave me a bicycle like this that I started to clean up for my wife. She said her knee would not allow that foolishness.



Had an old Schwinn excerbike similar to this that I used parts off of for a 24" Stingray project. Started to make it into an electric trike, but that idea lost steam.



Along with some moped wheels for the drum brakes, studying old pre-WW1 motorbikes for ideas came across this Wagner.



Hack them up, and hot glue them together and get something like this.

[Mr. Gangrene Genes]

Added some crank pedals off a 24" Schwinn, a fork off a 26", with a 20" tire to match the moped tire diameter, seat off the Murray and viola a rider.



Felt like the front end was somewhat low so tried a 24" tire, much better.
For good measure put on a 26", nope too tall. Made a fixture jig to set the ride height.
Making a leading link springer fork with the floor stand and tabs from the excerbikes.

[Con-Tiki!]

that's pretty cool. The springer reminds me of the front-ends Greeves used on their machines...
Will you be able to get a tag for that ?, the laws in PA are really strict with regards to bikes/mopeds/scooters.

[Lilgti]

I dont know why this thread hasnt gotten more attention! Thats a rad frame you've built! cant wait to see the end result!

[NumbaFo]

Awesome build, keep going, wanna see more!

[Mr. Gangrene Genes]

Howdy, thanks for the kind words of encouragement. Most people that see it quote Star Wars “you came in that? You’re braver than I thought”. No license tags or insurance, Missouri is pretty lenient on scooters/motorized bicycles. The big one that put the kybosh on the Tecumseh in the first picture is the 50cc limit. I was irritated that none of my engine stockpile would be legal, bit the bullet and bought a GXH50 Honda 4-stroke. Have enquired with LEHR to see if they have a propane conversion in the works for it. No reply. Considered the 4G Gilmer tooth belt transmission, but none were/are available. The Honda is a high speed engine so there will be a 12 to 20 chain drive jackshaft as suggested by the guy at Max Torque. Over 16, valid driver license and an automatic clutch are a few of the other restrictions. That last item eliminates the Johnson Bar roto-tiller style activator I wanted to use. Currently trying an old Vari-plex variable width pulley, but have left my option open for a centrifugal belt drive clutch. While I am sure the local law enforcement has better things to do then hassle a middle aged guy commuting, the styling clues will all be bicycle, not motorcycle. In that regard and because one of the intermediate belt drives fouls the upper tube, the fuel tank will be mounted in front of the handlebars like a derny pacer.

[scrumblero]

thats genius!! this is what makes this site great!!

[masterpoop63]

DUDE THIS IS SWEET!

[Mr. Gangrene Genes]

Here is the first attempt at engine placement. Actually second, had bent the lower tube to the left to clear the Tecumseh flywheel. Wadded it up badly trying to twist it over to the right for exhaust clearance on the Honda. Bending tube well is not one of my skill sets (yet). Usually find it simpler to splice together the factory bends from salvaged frames, hence the somewhat coral snake appearance. Not pleased with how high the engine sits in the frame. It is only 13 pounds, but want it as low as possible for center of gravity, clearance, and it just looks ungainly where it is. Worked on springing the fork, it is held rigid here with hose clamps. Like the looks of the Felt Abraham Linkage fork, but it would need to be lengthened and it costs money, something I have very little of. Kept trying to put the springs in front which would foul a fuel tank and a headlight. Finally I noticed all the space behind the lower triple tree and will put the springs from an office chair there.

[Mr. Gangrene Genes]

Cut out the raggedy lower tube and replaced it with part of a school bus seat frame & leg.
Looking less & less like a Wagner, more like a functional street fighter.
Pulley above engine is the upper jackshaft to multiply and route the power.
Wood is just the locating fixture jig. Using a go-kart front hub cut in half for the high speed bearing support.

[Mr. Gangrene Genes]

Made the office chair springs mount in the empty space behind the lower triple tree. Used 3/16 plate as large as would clear the frame, looked like owl eyes and the extra diameter didn’t really add much strength.
Decided some thickness would help the stiffness. Slash cut some leftover roll-bar tubing, bridged them together at the tall end and trimmed the plate down to their width. Steering head bearing cups are just the right size for the upper retainers. Had a castoff roller wheel from something that was mounted in a piece of channel. Don’t really enjoy drilling holes in steel, so cut the shape I wanted around the holes that were already there for the lower connetions.
Boxed the engine mount and got some 1-5/8 x.122 wall seamless tubing from FlashBurnFabrication.com a local company that was great to deal with. Used it for the two lower jackshafts and a half a go-kart hub for the upper. Going to have some friction lost in all the bearings, belts and chains. Ok, maybe not much loss in a proper fitted chain.

[Mr. Gangrene Genes]

Not much progress to report. Was torture testing the springer by standing on the engine mount and riding over chuck holes and the dip in the neighbors driveway. It was going really well, and then not so much. The springs started binding and the front fork had bent forward like a lowrider. Maybe won't have happened just riding instead of crushing it, glad it happened now instead of on the way to work. Also had a problem with the spring mount going over center and stuffing the tire into the lower triple tree. Straightened the fork a little too well, now it would over center with the slightest hint of a bump. Bent the tabs back farther than it started, about 45 degrees. Then the fork looked liked a chopper and the effective spring rate was sky high. Eased them back to about where they were to start and made a girder truss out of the old seat stays, more coral snake. Hope it holds.



Shot from the top that shows the spring plate a little better, that is a shim under the right side spring.



Need to work on the intermediate pulley and idler, as well as make some new rear axle plates. I am afraid the axle will pull out of square with the bicycle type drop-outs, even with stops.
Thanks for looking.

[Mr. Gangrene Genes]

Finally got back to the motor bike, spent all my time and money on the JEEP and it is still not finished, nor does the D4 Caterpillar run. Fellow is not too bright to spend all summer working on an open car and motor bike while letting his enclosed 4wd languish and fall out of license with winter knocking. It is what it is, make the best of it. Drilled and formed the flat bracket in the center and used a mower belt that was lying around, some zip strips to hold it together long enough to take a few rides. Pleased that it runs, marginally better than pushing the pedals. Somewhat disappointed in the lack of pep, some power loss over the scooter because it is a 50cc 4 cycle instead of the 50cc 2 cycle, half the power strokes. Think it is also over-geared since the motor doesn’t want to rev up under load. Ordered a 13 tooth sprocket to replace the 16 tooth final driver behind the aluminum pulley, hope there is chain clearance at the bottom bracket. More buzz in the pedals and grips that expected, not unbearable, just mildly annoying. Riding downhill, it appears that the centrifugal force on the heavy primary belt pulls it down into the adjustable upper sheave to make sort of an automatic overdrive, shall see if it really does work that way. Need to police up a few things and make a lever to remove tension on the idler when required, too much drag to pedal without the engine running. Would have been cheaper to fix the scooter and ridden it all summer.

[54shadow]

Shear genius!

[cman]

A genius at work. Pretty crazy build and fun to read.