In frame Predator fricton drive build

[Psycledeliac]

Wow, this thread is 18 pages of pure awesomeness!

And that link Rusty posted to the 1.5" stone wheels is what I've been unsuccessfully searching for, thanks for posting!

Kudos on the genius design, Wayne, and kudos again.
I'm not a big fan of in-frame engines, but this one is a real exception, I just love it

 

[motorhedfred]

Wayne and all the rest of you guys that have posted on this thread....thank you. Most of all thanks to Wayne for taking the time to chronicle this build so well.

I've never even given FDs a second thought until I started reading this and watched the second video. I was amazed at the perfomance of your build. This might be the direction I head. I'll be interested to see how the tire wear issue plays out with the stone wheel, but the performance improvement might just outweigh any increased tire wear.

I have a suggestion for the idlers/clutch mechanism on your next build.

Picture a delta or V shaped steel plate between the two belts and pivoting on the bottom point. An idler pulley on each of the other points of the triangle, one on each side of the plate. pushing it forward it engages one belt, pulling it back engages the other. The middle would in effect be "neutral". Add a shifter with a notched gate to hold your high/low selection and mount it on the right side like the old Harley tank shifters for easier access. You could spring load the shift lever so it defaults to neutral for safety. If you get in a jam, just slap the knob and it goes to neutral automatically.

I certainly don't mean to imply your design isn't brilliant, it for sure is. I just can't help thinking of other ways of doing things....I drive myself crazy sometimes because of it. It's also the reason I have boxes full of hardware in my garage and shed from ideas that didn't work. LOL

MHF

 

[wayne z]

Thanks guys for the kudos.

MHF, It's strange how genius minds can re-invent the same things.
I met a guy that built a 2 speed belt tranny on his kids go-kart back in the 80's with the same simple control idea.
He used a dual sheave cent clutch on the motor, and a round,shaft mounted disc between the belts to mount the idlers.
The disc gives you the option of changing placement of the idlers when working out the bugs. Definitly much simpler than the two articulating levers wiih over center detent springs ect that I figured out. Definitly going to use this method on my next tranny.

I am still amazed at how good this stone wheel works. No slippage with aggressive throttle even in standing water! I don't forsee excessive tire wear. No slipping and a relativy fine 80 grit stone should be easy on the tire. Time will tell. I didn't have much wear at all on the old 1/2 worn tire I started
this build with. After 500 miles without much wear I changed it after a flat.
The freedom from hasseling with a drive chain and sprockets is awesome!
Thanks again to all who have followed this thread.

 

[motorhedfred]

LOL @ genius....I've been called a few other names in my 56 years...but never that one. Guess what I was thinking about when I woke up this morning, (keep it clean now) a 4 speed version of the same thing !

It would be just what a low power, low RPM engine would need...say an engine like a little atmospheric intake V-Twin made from an old air compressor pump for example. (provided drag from the idling belts doesn't drag it down)

A pair of 5 speed drill press pulleys with no belt for the middle grooves....2 shifter plates in there instead. The ones on my little drill press would work, too bad I need it. Mount it all under the engine to keep the width under control. The shifter lever would work in an H pattern like the old 4 on the floor Hurst shifters.

Maybe even control it with this....

Manual 3-speed Shifter . Mr. Gasket 7667A.1949-86 Autos | eBay

I need to retire so I can find the time for all this craziness.

MHF

 

[tn97kouki]

i would like to do something like this with my hs50 . What size pulleys and roller would it take to run correctly ?

 

[wayne z]

I would try a 3" clutch pully driving a 6" jackshaft pully with a 3.5 dia. roller for high gear.
This will give you an overall ratio with 26" tire of 14.86:1. This equals 39mph at 7500rpm, with any sized tire actualy.

 

[wayne z]

Well I have proved what I already knew, that knobbies don't work well with FD, especialy the stone wheel. Severe howling from the cupping after only 25 miles LOL.


I just ordered some Cityslicks for replacement. Anyone got any ideas or advice about tougher replacement tires?
Links to 26" motorbike or simplex tires? I know this has been discussed,I tried the search but got nowhere.
I'm gonna try contouring the stone to a slightly concave profile colser to matching the tire profile. Better fit, means less pressure needed and this might improve drive efficency and reduce tire wear some.

 

[motorhedfred]

Wayne, does the stone wheel contact across the whole width of the tread ? If not, maybe a tire that has a solid strip in the middle of the tread would work better for the stone.

MHF

 

[happyvalley]

Well I have proved what I already knew, that knobbies don't work well with FD, especialy the stone wheel. Severe howling from the cupping after only 25 miles LOL.
View attachment 42510

I just ordered some Cityslicks for replacement. Anyone got any ideas or advice about tougher replacement tires?
Links to 26" motorbike or simplex tires? I know this has been discussed,I tried the search but got nowhere.

You'll get more even wear with smooth or no tread than a knobby, plus a much smoother ride, but the problem of accelerated wear will still exist using a stone roller on dry surfaces. I only use slick tires and the stone rollers I use work well on wet surfaces but as soon as the road dries I can see the difference almost immediately by the amount of scrub dust that gathers on the bike parts.

A hard compound tire would be best but then that sacrifices a bit of the ability of the tire to hold to the road and why most bicycles tires today have soft compounds and advertise how well they grip the road. Further up the food chain are "dual compound" tires, hard in the center and softer on the edge of the tread for cornering but they tend to be pricier, IE: Michelin, Bontrager, Continental, etc. Whether it's worth more expensive tires to put a grindstone to is debatable. For me the solution has been a roller that takes a minute to change at the side of the road.

 

[tn97kouki]

Sounds good for high gear . What about low gear ? A 2" pulley on the output and a 8" on the jackshaft ?

 

[wayne z]

Sounds good for high gear . What about low gear ? A 2" pulley on the output and a 8" on the jackshaft ?

That's too much difference. You will rev the motor to screaming in first and it will be lugging in second when you shift. I would try a 2" and 6", that gives you 26 mph at 7500.

 

[cannonball2]

OK, some more observations on rollers. I run direct. Have really been lovin the 2.1 roller, great cruise, good hill climbing, seems to be on the engines torque plateau. I have carefully watched the "death" of my most recent tire. The tire seems to cup more with a higher drive ratio, ie the power pulses are spread over a greater tread distance. When they happen they dig hard in a localized area. With a smaller roller they happen more frequently and tend to overlap on the same section of tire, so more closley spaced tread is handling the drive. The engine is reving more, but it is actually unloaded to an extent, which I feel is easier on it, the roller and the tire. With the big roller its faster, more agressive and burns more fuel. With the smaller roller it is revving more but less agressive on its strokes, easier on the tire and fuel burn is less. Personally I like the bigger roller, but in the long run it costs more. There is a true optimum roller size for each drive set up. With bike tires there is an HP limit that the tire can handle reasonably. With higher HP and a big roller the tire is the looser. The trick is the balance of all of it.

 

[tn97kouki]

I appreciate the input guys .What I would really like to do is a 2 speed setup like Waynes running to a jackshaft and then instead of the friction drive have a belt drive running to the rear sprocket . I haven't been able to get that worked out in my head yet because the rotation of the output would be running backwards . Here are a few shots of my bike if anyone has some input . Thanks guys
http://motorbicycling.com/attachments/f3/41918d1320709002-got-lucky-jaguar-016.jpg
http://motorbicycling.com/attachments/f3/41919d1320709076-got-lucky-jaguar-020.jpg

 

[cannonball2]

Turn the engine around to the other side all the belts are then on the left. The final drive belt would be on the inside with the multi-speed belts on the outer I have a single speed bike driven this way.

 

[cannonball2]

BTW Wayne I am shamelessly copying your bike in a single speed version. What did you do for/or to widen the cranks?

 

[wayne z]

BTW Wayne I am shamelessly copying your bike in a single speed version. What did you do for/or to widen the cranks?

I used an acytelene torch and a cheater pipe. I heated and bent the crank while still installed on the bike. I made a plywood wedge to use as a pattern to eyeball and make the bends equal on each side.

I did remove the pedals. Just barely heat to not quite red, then bend the arms till the ends are abt 2" out from stock, then heat close to the tips and bend enough to make pedals parallel.
Be sure and keep the BB and bearings cool with a wet rag and water hose.
Use minimal heat, and the chrome will polish out fine where it was heated.

Good luck with your build. are you using cent clutch or idler clutch?

 

[cannonball2]

Thanks Wayne! Gonna use a Maxtorque I have. Going to drive a 2.4" roller, have not figured the gearing yet. This is an HF 79cc. Once its done and sorted out will slide in a Preddy.

 

[tn97kouki]

Do you guys use a formula to get the ratio or do you know of A program I could use ? Instead of belt drive on the output , I am thinking of sticking with the chain drive . It would be kind of a combo of the q-matic and Waynes setup . It would be jockey shift and I could still run the 50 tooth sprocket I already have on the bike . I just need to get this ratio stuff down . Thanks guys for your patience .

 

[cannonball2]

There are calculators through out the forum, I have posted one my self. Or divide the driven by the driver on both the primary and secondary. Multiply the resulting numbers together and that is your overall ratio. For a multi just do the steps for as many speeds as you have. Example primary 6" driven pulley divided by a 2" driver=3:1 final 50t divided by 10t=5:1 5x3=15:1 overall.

 

[wayne z]

I use the calculator that is the permanant first thread of this DIY forum.
For fricton drive, use the roller dia. vs tire dia. for the last entry made.

On this build, I am running 14.86:1 total reduction in low,for 26 mph at 5000rpm, and 9.90:1 total in high gear for 39 mph at 5000 rpm.