Rear belt drive?

MT,
I know your art fish bike is set up for applications most riders will not need, so it is hard for me to translate your experience to what most of us would need a belt drive to do. For myself there is no need for being able to climb billy goat hills or walk along slowly enough for parade ground situations. It sounds like your needs are best met with chain final drive. My own needs are more typical in being able to start off from a dead stop without excessive slipping, climb moderate hills and run along smoothly at a maximum speed of 35mph and most often 20-30 mph... the same kinds of situations an old Whizzer motor bike was so good for. For most of us, if we can come close to a Whizzer experience with our bikes we'd be happy campers.

For myself I want to try a belt final drive. As for which belt will work, a nice thing is that there are three types to try. Your comment regarding a small diameter pulley doing best with the cog belt is helpful and might suggest a larger drive pulley when initially setting things up if the link or V belt is desired. We can try one type and if it is found lacking, then try one of the other options.
SB
 
http://www.ebay.com/itm/Washing-Mac...803?pt=LH_DefaultDomain_0&hash=item4857d6464b

MT had mentioned at one time using an aluminum washing machine pulley (which did not work out for his needs, I guess) and I thought I would check that out, my thinking being that discarded washing machines have pulleys for free. I went to ebay for a look and found that most standard washing machine pulleys would not be applicable for attaching to a sprocket. However, one type from Hong Kong looks like just the ticket. You can see in the link that this one with a diameter of 95mm (3.7") is only $9.59 shipped. It would be easy to drill and bolt it to a rag joint sprocket or in my case to a manic mechanic sprocket with worn teeth. No, these are not high grade pulleys and are described as being "metal" which probably means pot metal or a low grade of aluminum. But how good does one need to be since it is to be bolted to a sprocket?

There are a variety of sizes ranging from 3.1" to 5" diameter, all for 1/2" V belt. I'll need to measure the driven sprocket on my bike right now to see what the diameter is and then give a stare at the driving sprocket on the back side of my transmission to see what diameter that is. Might be that I can bolt one of these pulleys on to it as well so long as the drive ratio works out.

At the very least I can order a pulley for the driven sprocket (the one on the rear wheel), purchase a link belt from Harbor Freight and experiment with my Panther this spring. I won't wait to change the engine, but will try the belt drive with the current engine as a kind of "proof of concept" experiment to see if the idea works. I should be able to keep costs down to the $50.00 range ($25.00 for the link belt which I want anyway, another $10.00 or so for the driven pulley and another $10.00 or so for the drive pulley = $45.00). That won't break the bank and will tell me more than I know right now about a do it yourself belt final drive conversion from chain & sprocket drive. I think I have something I can use for an idler pulley if I need one. If I'm barking up the wrong tree here, please give a woof guiding me to the right tree.
SB
 
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Could be pressed steel. Whatever the metal it is probably adequate for our purposes. I did some measuring just now on my sprockets to match pulleys to and need a large one for the driven sprocket which is 10" diameter. I had to go that big to compensate for the sidecar. I'll see what I can find on ebay in something used that big. Shaft size doesn't matter for me if it is getting bolted onto a sprocket.
SB
 
I sort of think that color which is not silver/white, it might be pressed steel.

You did some good searching. Free shipping, but I expect if you order distance ship for free, think wait time to get it. You though have a plan going though, I sort of kept things in my mind and wrote some down. Some how it works alright.

You already once built a motor bike with side car I think, so you have an edge!

Yea, I will get to finish building art cover, but other things has it on hold.

MT
 
I got a note from Curtis Fox this morning which raises some legitimate doubts about what I'm attempting to do. I appreciate his thoughts on the subject which make some sense to me. When you look at old motorcycles which were belt drive they never have small diameter driven pulleys. With all of the variations that were tried in those early days you would think you'd see a small sheave. But I've never seen one and maybe that's for a reason. Here are Curt's thoughts on the subject...

"Good morning
Last night i was reading the post that was about pulleys,don't know how i missed it. But i don't think it will work,think of the 10" pulley as a lever. If you spin the back wheel with your hand it turns easy,but if you reach down and turn it with the sprocket it turns a lot harder,and takes a lot more force. Chain has teeth were a pulley has just the rubber against the metal. With that small of pulley it might just slip all the time as not enough leverage. Yo have the bike right there try turning the wheel with the sprocket then turn it with the tire.

I was going to post this on that forum you can if you want. About the smallest pulley you would want to do on a 26" wheel is a Wizzer. a 20" rim would be close to that size as the rim is smaller then 20" more like 16" If you studdy the old bikes like harly you will see the are mounted with Z shaped metal tabs that just bolt or riviet to the rims. Like Harry and the beach cruser or Mr.B and the excaliber. That also creats another problum with the bigger wheel pulley you have to drive pulley up closer to the seat to get the belt through without cutting the lower chain stays. Look at all the truble Measure twice had with his setup before he bought the Wizzer pulley. If it were me i would use a 24" rim for a pulley on the rear,and run a suppertean belt like Mr.B did. Or just a V belt. Sure hope i didn't blow the bubble but i just don't think it will work
Curt."

So what do you think?
SB
 
And Curt has given me yet another thing to consider.

"Just some thing to think about. 2" pulley divided into a 10" pulley is= 5 to one ratio A 2" sprocket is about 14 teeth and a 10" sprocket is about 50 teeth 14 into 50=3.5 to 1 or there about. so you can see that chain and pulley are different"

And I thank Curtis again for something else I didn't know. So If I had a sheave that was say 20-24" about what size drive pulley would I want? Something like a 3 to 1 reduction is what comes to mind, but that seems like a pretty big drive pulley, what, about seven inches? (Obviously I'm not real good with this stuff coming up with the answers. But I can ask questions like nobody's business.) And if the driven pulley was 10" (assuming that it would work) then the drive pulley would need to be around 3"?

Just measured the Whizzer sheave and it is roughly 14 1/2" in diameter. Not that much bigger than 10", eh? If I try it then it will definitely be with a cog belt to get the most bite I can. Whether or not the belt has excessive slip is what defines success or failure. The smaller the sheave the greater the chance of slipping, yes? It would sure help if I was smart, but I'm not letting a little thing like brains stand in me way. Onward!!! On, you huskies... arf, arf!
SB
 
Its more the cercumferance then then the diamitor witch is 3.14 times more surface( more bight ) Yep 24 divited 8= 3 to 1. Its what up front that gives you a steep ratio,don't know what the Q-matic has for ratio. Most of the older bike run about 3" to rear Wizzer pully. Thats close to what my old Monark twin had for setup,and is the same as Wizzer. ................Curt
 
Thanks, Curt.
I learned today from Tinsmith that EZm has already done the conversion of the Q-matic to belt final drive. I don't have many details yet, but it looks like they are using a standard Whizzer sheave with a 3" drive pulley at the clutch. I started another thread...

http://motorbicycling.com/showthread.php?p=595537#post595537

...in the hope that one of our forum members knows more about it or is even using it. I saw a picture on another bike forum of one of Helmut's frames with what looks like a Whizzer sheave and a belt coming from a Q-matic. Looks good, too. This was from 2008, so there must be some people out there using it.

I went to the EZM website hoping to learn more and didn't find much. No details about cost or anything, but I sent an email asking for particulars and will pass along what I learn.

Curt, the more I think about what you said regarding the size of the driven pulley makes sense. Bolting a pulley directly to a sprocket may be a dead end. I don't want it to be and hope someone tries it, but I think with what I want to do I'd be best off using a 3" drive pulley (don't think there's room at the transmission for anything bigger anyway) and a standard Whizzer sheave. If I can figure a way to use a bigger drive pulley then I'd like to try lowrider's approach using a 26" rim bolted to the wheel rim. Lots less money involved. I don't remember what a Whizzer sheave costs, but they aren't free.

Thanks for all your help, bud.
SB
 
14.5 divided by 3 =4.8 to 1. Last i looked they were $39 but you can look on the bay and find them cheper i think.................Curt
 
The one on ebay comes to about $50.00 with shipping. I think I will explore alternatives. I have a lot of bicycle rims and was looking at Briggs & Stratton conduit clips for holding a rim to the spokes.

http://www.ebay.com/itm/Conduit-Cli...7&pid=100005&rk=2&rkt=6&sd=400842180129&rt=nc

I ended up having to use these for my whizzer rim on the kindalikeawhizzer build since the clips which came with the sheave did not fit my 11 gauge spokes laced in a four cross pattern. msrfan suggested using these as an alternative and they work great. Expensive little buggers, though. I believe I still have some. Another option is that I may be able to use the unused whizzer clips with a bike rim for a freebie sheave. I would think that a rim from a 16" to 20" wheel would approximate the size of a Whizzer sheave. We'll see. If I can save $50.00 and also have the satisfaction of making do with what I have, that would be very cool.
SB
 
curtisfox said:
Yep a 20" wheel is about 16" without the tire............Curt
Click to expand...

Perfect...

By the way, those conduit clips need to have the little tab deals ground off. Think I'll take a look through my wheels today for a sheave, just to know whether or not I have something suitable. If not, I'll keep a look out when making dump runs. It is never too soon to start setting aside parts for a future build.

I can't remember, Curt. Your bike project is to use a Briggs engine if I remember right. Are you planning for belt drive?
SB
 
You will have to measure for sure, but bike wheels are measured with the tire on and are smaller without the tire. Went through Harry's villers beach cruiser build trying to find pictures but they seem to be gone. That is what he used with Z shaped metal tabs bolted to both rims. But then you might run into clearance with the stays, seems to never a end to the work of doing belt drive. Prolly why you don't see to many. I know that Mr.B did on with tabs on his Excaliber 09,that way you are turning the rim and not the spokes.

My briggs build will be belt primary and chain to the rear, as i want to do as i did as a kid. But the one coming after { Fox Burro }will be belt drive. Had that Monark twin when i was a kid sold me on it, quiet and smoth just the engine hum,with the long fishtail exaust.
 
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
 
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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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
 
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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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
 
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