Of shoes and ships and candlewax etc.

trackfodder

Member
Sep 8, 2008
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I have just come in from a very successful shop session and feel higher than a kite. I was working on my Monark with the 3-speed jackshaft and ideas kept flooding my mind. I glanced at a pair of Motobecane rear coilovers and rear suspension came to mind. Most of what I have seen attempted didn't pay much attention to chain slacking as it swings. Try this---Take the crank out and find some bearings to replace the crappy peddle ones, maybe some with snap ring grooves can be found. Anyway, pass a straight shaft through and put some flats on it to bolt lightweight-style peddle arms parallel to each other using the wedge bolts Slip tubing over them and weld for a swingarm.
Outboard of this, a sprocket to drive the rear wheel and a pulley from the motor belt on a bearing arbor rotating on the swing arm shaft. The chain will always be at constant adjustment. To go fancier, use needle bearings and run the swing arm off the small shaft and put the engine drive in one side and the sprocket on the other on a rotating tube containing the swing arm shaft. You could use a derailleur system if you wished. The upper rear fork would be a front fork with a valve spring sliding in and out of a pivoting receiver behind the seat post. A milled slot in the fork would control its travel limits with a pin or perhaps simply use the fork nut in a pivoting yoke to limit the retreat of the fork stem. It would require pivot bolts at its connection with the swing arm. This system would eliminate any side wobble in the rear wheel. So much for that. Here's what I accomplished. The Hodaka tank I mounted has 2 fuel cocks and I intended to simply wye them together and run to the carb through a filter. Fine, but one cock barb was about 1/8" from the muffler, which attaches at a funny angle, so I pulled the muffler to see if I could invert it. Nope, it interfered with the 2nd jackshaft, and also the engine port is a D shape and somewhat larger than the round muffler flange. AHA Back Pressure! I made a 1/4" thick plate and used some 1-1/4" trampoline support with small radii bends to fashion an exhaust pipe.
It didn't come easy. I shaped the D in the end and inserted halfway into the flange and welded inside so as not to interfere with flange nuts. I discovered my Roto Zip that I have learned to despise for its difficulty in controlling, is a pretty darn good die grinder with the 1/4" chuck and a carbide burr. My air situation sucks anyhow so this is a real blessing for me. I cleaned up my internal bead in short order. With my oxygen cylinder's dying gasp I managed to crank all the necessary bends into the pipe. I used the old trick for fitting expansion chambers to racer frames. Cut a pie slice out of one side ALMOST through and a straight cut on the opposing side. Bend the pie slice closed with torch and insert and weld the cut out in the other side. Brought back many memories of the endless line of racers wanting chambers made and fitted. I am as good as I ever was, and that feels good. Tomorrow or whenever I get oxy I will finish my welding and scarf the pipe at a sexy angle..
I still need to make a chop saw cut and bend it up parallel to the ground. THEN I can paint it with BBQ grille rattlecan and make the simple little wye fuel connection I set out to do tonight. If I ever feel flush, it might get chromed or maybe silver baked manifold paint. I have an idea the changes are going to wake up the kitty One last thing-The Roto Zip IS useful for one thing--With a radius rod attached you can cut huge round holes in sheet metal from a pivot.
Also the word is SEALING wax, not candlewax. I know better but it is impossible to edit a title once posted.
 
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pictures brother
we need pictures

you can have suspension with the drive sprocket higher then the pivot for the rear swing arm it is just that the further off it is the more of a tensioner will be required

mopeds put the pivot rearward of the drive sprocket but have the pivot, drive & rear sprocket in line in the "normal operating range" I think some dont use tensioners

I remember from a hodaka manual (BTW a hodaka ace100 was the first bike I ever rode)
that when decelerating with a 2 stroke its important to blip the throttle every so often to keep fuel & oil in the crankcase
blah blah blah

TF you are about as demented as I am :)

have a great new year
take care
JAK
 

trackfodder

Member
Sep 8, 2008
347
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Tonight I discovered the crappy handling of the Schwinn clone springer on the yellow bike was probably due to the fork top nut being a bit loose, allowing the spring anchor to hunt sideways. :confused:
Anyhow, I was back to the 1910 Pierce type front fork. I origionally thought I would use shoulder bolts for pivots in the 1/4" link plates, but Fastenal thought they were worth about $27. I then thought about sticking 1/4+" stainless 1/2" tubing in the links. Nope, they would probably swell. Tonight I got some $3.99/lb grade 8 1/2" bolts from Atwood's and turned the shanks to 3/8" and threaded, leaving the required 1/4"+ shoulder. Assembled OK. The frame with the short head tube I 'm stuck with for that fork is an old Flying-O 24" lightweight. To use it , I need to rig it's tail for 26 balloon anyhow, so I will chop the 2 tubes aft of the crank hanger and install a pivot tube for a swing arm using another shaft hanger housing that uses a straight keyed shaft and as I suggested earlier, key peddle levers parallel and slide tubes over and weld for the swing arm. With a proper rear axle receiver plate, I can pivot a front fork off that and use valve springs on the fork stem passing through a 1/4" plate behind the seat post. I should be able to retain peddle-ability for legality. I think I can stick the HT in it and have room for a Silent Grey Fellow type gas tank. I have been thinking about getting the HT cryo treated. They are made out of crap anyhow and the treatment equilizes the distance between molecules and triples the life of tools, valve springs, brake discs, etc.
and stabilizes the cylinder bore as it heats so it doesn't distort. It costs $4/lb in Broken Arrow Ok..wee.
 

trackfodder

Member
Sep 8, 2008
347
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Nope, the Schwinn clone fork is a flimsy piece of crap. It is rubbery around the base pivot on the stem. I have a REAL one on a 20" that might be ok. Its off one of those show-off models with the banana seat.
 

trackfodder

Member
Sep 8, 2008
347
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I pulled this from elsewhere because it belongs here. --------------------------------------------------------------------------------

Well there are up days and down days. Today reason crept in and after welding the swing arm shaft hanger in place, reason told me<"You ain't gonnna peddle this thing. There is no room for the peddle shaft. If I stuck a sprocket out there to clear, it wouldn't line up with anything. :-|| The HT.blady is no longer a candidate, but I have a 6ft. version of the Atlas Van Lines unlimited hydro with the Allyson V-12 that has a backward turning Quadra 2.2ci. with 2.2hp and a rope starter that was WAY inadequate for the boat. Been waiting for a butt-kickin' chainsaw to come along I could upgear with Gilmer pulleys and belt. I don't want to get started with 1/4 scale boats. Anyhow, I can put the necessary sprocketing in the front shaft hanger and use that engine Also there is a Kawasaki snow blower mill that I stuck a weed eater centrifugal clutch on that also has a rope starter. It was too rpm limited for the 1/4 scale Crackerbox boat. About 32 cc. At least it's cute..mbv.
EVERY MAN HAS AN IDEA THAT WON'T WORKscratg
 

eDJ

Member
Jul 8, 2008
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Wayne National Forest
Since we don't have any photo's as Keith's concept is in development, I illustrated
it with a sketch for him. Understand, this is how I see it to work and I think
it's an interesting solution to several problems at once. A centrifigul clutch on the motor's
output shaft could drive a V belt to the Arbor Shaft where a pinned V belt pully would turn
the shaft thru the floating lower forks riding on it. The pinned sprocket at the other end could
then drive the rear wheel's sprocket without real need of a spring loaded chain tensioner.

The pinned sprocket hub & V belt hub would trap the lower fork mounts securely while the
upper fork spring would ride securely as Keith described in a receiver mounted to the seat post.
the down tube in the sketch may be modified in the finished form to provide a platform for the motor
and foot rest.

With a good springer front end and the floating rear suspension I could see this platform capable of
using a 6 hp recoil start motor and have adequate power to start off on motor power and take you
about anywhere you would want to ride.

Interesting ideas and clever solutions Keith !

Considerations I see:

Good reinforced welding of the rear forks, and larger rims & tires suitable to the speed that will be
attained.
 

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trackfodder

Member
Sep 8, 2008
347
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Re: Of shoes and ships and candle wax etc.

I'm a bit disenchanted :-||since I screwed up about the peddle sprocket, but determined to make the thing work just for the challenge. I decided where to put some pegs on it since there will be no peddles. I have dropped a 1" tube ~5" long vertically from the front down tube, about 4" in front of the front shaft hanger. Then triangulated with a horizontal tube to the junction of the down tube and shaft hanger. .weld The vertical tube holds a goose neck from a BMX bike that has 4 Allen bolts holding the bars. This will hold my foot bar. I saw some 1" hand grips for a wheelbarrow somewhere. I can reverse it to shift the bar position. If I use a 3-speed rear hub, it will freewheel and I can't start an HT. That's OK, I have lots of ripcord engines anyhow. This also leaves the possibility of a split spring-loaded pulley from an AC treadmill with an idler pulley to vary the speed with a centrifugal clutch on the engine. I can either do it ala 1910 with a big cobby lever and ratchet teeth to hold the setting, or use a rocker heel-toe peddle like an old
H-D clutch with a friction clutch to hold the setting. I think Servi-Cycle did something like that. I still need to find the front fork that is going to be my top rear fork with the springs on it. I need to find some decent bearings for the shaft hanger to run my jackshaft through. If I don't go with the
S-A tranny, I don't need to cross over and I can do it with a sprocket and pulley on a common arbor pivoting on a stationary shaft. As you can see, I'm still thinkin and plannin .spr. KW