Rear belt drive?

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silverbear

silverbear

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I do think it is a terrific idea and would try it IF the ratio worked out. On a 26" wheel I don't know just what the rim diameter would come to, but a lot more than than the Whizzer sheave, essentially then a bigger pulley. With my Qmatic transmission I am limited by the amount of room available to how large the driving pulley can be, I believe it is 3". Trying to use that smallish drive pulley with a really big driven pulley would mean the bike would move along pretty slowly. If the drive pulley could be bigger, like 5,6 or so inches in diameter then a great big pulley would be okay. I'm still unclear about just what sizes are just right, but since EZM is using a Whizzer sized sheave and a 3" drive pulley it must work out okay or they wouldn't do it. I'll follow suit on what has worked for somebody else. If you were free to use whatever sized drive pulley you wanted then I think lowrider's sheave idea is super. A 20" wheel comes out to about 16" at the rim, pretty close to the diameter of a Whizzer sheave. I believe that's what I'll use, which means it has to be attached to the spokes.
SB
 
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curtisfox

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Trey said:
SB- I've been reading along wondering why you're deciding on attachment methods... Because it's not in this thread... and THAT is: someone (wheelbender?) mentioned bolting an unused rim of the same size onto the rim of the drive wheel, and another member (not you after all) said they thought that was a fantastic idea, and would try it. I'm missing lot's of details, but it was someone who I thought knows their stuff. I'll try to find and link it.

Trey
Click to expand...
Yes its been done many years ago back in the 40's i think was in popular machincs mag.
http://countryplans.com/vintage_farm//bigkids/PowerBike.pdf
Don't remember who but one of the members JB Welded one rim to another and had good luck with it................Curt
 
silverbear

silverbear

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Curt,
That's a neat article and well worth some study and saving. I've only skimmed it, but see they are using what works out to be a full sized pulley (wheel rim) with a 3" drive pulley. I'll need to read it more closely, but it must work, eh? How big was the driven sheave on your Monark bike from when you were a kid (younger kid)?
SB
 
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curtisfox

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50 years ago,but think it was the same as a Wizzer,about that size anyway. I think they used the same parts just that it was a Monark version. Also had a regular disk clutch,sure wish i had it now......................Curt
 
silverbear

silverbear

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Curt,
I was just reading over the article and ran across this statement...

"To install
the belt, it will be necessary to cut the
lower left rear fork, as shown in Fig. 6. A
strip of 16-ga. tin, bent to a sleeve and
bolted over the cut, as detailed, repairs the
break and permits easy removal of the belt
at any time. "

Huh? They are cutting the chain stay so the belt can be installed, removing a section of it and the "repair" is a piece of tin to cover up the gap. Is that right? Well, that's no good. Am I reading this right?
SB
 
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curtisfox

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Yes the hart beat of america sorta, That and the old generator friction builds. They took a old car geenerator and cut the side out of the case welded the mount on the top stays run a belt back to it. it was spring loaded with a rod to raise and lower the generator. The motor set up front between the frame. Many of them built,infact i have a old rusty one i may restore...................Curt
 
Intrepid Wheelwoman

Intrepid Wheelwoman

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silverbear said:
Curt,
I was just reading over the article and ran across this statement...

"To install
the belt, it will be necessary to cut the
lower left rear fork, as shown in Fig. 6. A
strip of 16-ga. tin, bent to a sleeve and
bolted over the cut, as detailed, repairs the
break and permits easy removal of the belt
at any time. "

Huh? They are cutting the chain stay so the belt can be installed, removing a section of it and the "repair" is a piece of tin to cover up the gap. Is that right? Well, that's no good. Am I reading this right?
SB
Click to expand...
Yes that's what they're suggesting Silverbear, - though if you were to use a link type belt or a belt joiner you wouldn't have to do that. Otherwise I've always thought that was a cool old plan :)

Curt, - I like the sound of those old cut down generator based friction drivers. I wonder why I haven't heard of them before. Now of course the problem is finding an old generator that somebody hasn't decided is a 'collectible' and is therefore wanting a fortune for it.
 
silverbear

silverbear

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Does anyone know the diameter of the drive pulley on a Whizzer motorbike?

Anne, you point out an advantage to the link belt in not needing to cut the frame (and leave it open) to access the belt on that bike in Curt's article. We need some real life experience to know if belt slip is an issue. Wish one of our Whizzer riders would try a link belt just to see. Frame modifications on that bike are substantial to make room for the driven pulley, a second rim welded directly to the rear wheel rim, being of the same diameter. When that article was written the additional rim would likely have been for a balloon tire of 2.5" width. I wonder what difference it might make using a narrower rim of say 1 3/8" width. Might be that no frame alterations are necessary.

Using this article as a kind of model in how to do it might not be such a great idea. Cutting the chain stay and leaving it cut open in order to change the belt makes me question other things as well. That chain stay is there for a reason. If one of the builders on our forum did that the alarm bells would be ringing and for good reason.
I also wonder at the gear ratio with a 3" drive pulley and roughly 22" driven pulley (what the additional rim comes to without a tire on it) which is a good 7" bigger than a Whizzer sheave. That makes the ratio about 7-1, doesn't it? Yet with a 1 1/2 hsp engine the author claims a top speed of 35mph. Maybe, so. But I do think that a person needs to be objective about that article. Could be the author was mostly selling a magazine story which would have a lot of appeal. All these years later it got our attention. Could be the builder made a Frankenstein bike. I keep thinking about that chain stay with a chunk missing... on a bike that now has a motor propelling it down the road at 35mph with one brake, a coaster brake, to stop it. Hmmm...
SB
 
silverbear

silverbear

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Intrepid Wheelwoman said:
Information on that isn't easy to find on the 'net SB, but it looks like it's 20 inches.
Click to expand...
Not the driven pulley on the wheel, but the pulley on the other end of that belt... should tell us something about the gear ratio in relation to belt slippage. Whizzer must have figured out a good size for each pulley through many years of production.
I have a Whizzer sheave on my kindalikeawhizzer build and it is 15 1/2 inches diameter. Curt says that a 20" bicycle wheel has a rim diameter of roughly 16".

I wonder, too, what the pulley sizes are on the old Simplex servi-cycles. They were belt drive, too, weren't they?
SB
 
MEASURE TWICE

MEASURE TWICE

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http://motorbicycling.com/showthread.php?t=30085

Look at post #4 on this thread link it says : small 2.5" pulley on the flywheel
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Default Re: Whizzer NE-5 belt tensioner headache!
Hi John,

I sent you a reply to your email. I also included a few pictures. I think if you simply shorten the bushing [file or grind] the bearing will "clamp" tighter on the mounting plate.

The manual & automatic clutch have the same size pulleys, and the 15285 automotive wedge belt will also make the manual work better.

Due to a design flaw by Joe Lin [Tiawan] the original clutch arm isn't the correct length, and makes it very difficult to make the manual clutch work smoothly. It is either tight and the belt doesn't slip when stopped, or loose and allows a stop without "grabbing", but slips at higher speeds. Sadly a 29" belt is too long, and a 28" belt is too short [a 28.5" belt is needed]. He also wasn't smart enough to understand that notched belts were made to work with small pulleys. The vintage Whizzers used a AX26 [28" long] notched belt, and the clutch worked 100% correctly. He elected to use a cheap fractional HP belt [4L290] and it doesn't bend well around the small 2.5" pulley on the flywheel. The cheap FHP belt also stretches, and easily glazes.

Hope this information is helpful.

Have fun,

================================================

Maybe this is the information you needed.

I also looked at Memory Lane Classics, but the size is not listed. Maybe call as they were nice and talked with me when I was pricing Whizzer clone sheaves.

I ended up buying on Ebay my sheave but it was a bit needing of cleaning the weld seam that was rough. Also I drilled out the clamp threads and used my own stainless steel hardware with a bit more effort an cost.

2.5 inch is a bit smaller than the belt type centrifugal clutch Max Torque makes, I bought for my build which is 3.2" diameter.

http://www.maxtorque.com/html/pully_clutch.html

http://www.mfgsupply.com/4-865.html

MT
 
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MEASURE TWICE

MEASURE TWICE

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My 2" pulley is no longer being use between the top and bottom jack shafts. I use a chain instead. Maybe 3" should be the smallest used and I got the cogged belt to help make the tight radius bend without as much heating and fraying.

Below the link to the adjustable diameter pulley 3.5" max. I got a cogged belt that I use with it and it connects to the Whizzer clone sheave. I have it set under the 3.5" by a small amount, probably 3".

http://www.grainger.com/product/CONGRESS-V-Belt-Pulley-1L844

MT
 
silverbear

silverbear

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Just saw that, Curt. Perfect! Bolt it on to the sprocket at the rear wheel and off you go with belt drive. Now somebody needs to do it! I'm going with a 16" bike rim(from 20 bicycle wheel) attached to the spokes since I have the hardware, so it won't be me. Anybody??? Be the first kid on your block with one of these, eh?

http://www.fleetfarm.com/detail/speeco-w-series-hub-pulley/0000000033032

SB
 
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MEASURE TWICE

MEASURE TWICE

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The bolt onto sprocket I'm not sure exactly how, but the sprocket is on a flat plane most likely.

The spokes to clip to just please consider this:

The spokes themselves that span between the hub and the rim make kind of a cone shape on both sides.

I did have sort of an issue when I made my wood (coated with resorcinol glue) sandwich to connect a pulley to the spokes.

I looked to see what the inner diameter of the 16 inch pulley is for what you were looking at.

This was because if the pulley is planted onto the spokes, it will be some distance away from the spokes where the belt is riding in the groove of the pulley. What that means is the drop outs must be spread ever so much more for the assembly to fit.

Guessing it is about 1/3 of the 16" or roughly 5" inner diameter.

Anyway, I am not sure if there is something that you have that accounts for this, but my past washing machine pulley worked, but only after I got it to place the edge of the pulley as close to the spokes as possible. Now since it was too weak a metal (aluminum), I already replaced with a Whizzer clone sheave made of steel.

The pulley I used had its own type of spokes that I bent at an angle to match the angle of the wheels spokes cone shape. They did not break under the strain, but the pulley groove itself did. So I ended up not a complete DIY rear belt drive, but that is my story.

My past wood pulley sandwich on my thread: Page 9 post #90 picture.

http://motorbicycling.com/showthread.php?t=29678&page=9

More DIY the better, though I offer what I was confronted with with my method of building. Hope the info is useful.

MT
 
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