Bonneville America Forums Forums Technical Forums General Tech who wants a belt drive

If someone can do GOOD measurements I can whip up some CAD drawings of them.

Realy wouldnt be too hard to make, some drawings would be all a good machine shop should need. Why dont one of you engineers crank up the auto cad?

Patent Infrigement if you just take a part and copy it.Isnt it?

Ummmm yeah....
I just got a ...um... "copy" of autocad 2000 for my computer. I haven't mastered it yet, but what we really need is a bolt pattern, diameter, width, etc. That'll be standard no matter what.

if he can't do it I'll send you a used chain & sprockets.

Actually it is. I suppose I can't send mine to anyone for copying, ESPECIALLY now that I've posted about it publically. Oh well.

R&D= recover & duplicate

Hopefully this mythical machinist can find a way to make each sprocket a single piece. I've had the side plates on my front pulley get bent twice, semi-inexplicably. The first time was when my belt broke. The second is when my saddlebag bracket whacked the belt near the rear pulley under full shock compression whilst giving a young lady of rather considerable size a ride. I was able to fix it both times but it is a bit disconcerting.

Well this might be one of those things where its like how different can you possibly make it?

At any rate, if someone does have ideas, I'm happy to help with drawings. Or maybe if we can just give a machine shop some overall dimensions and they can take it from there...

for the right price, I would definately be interested

>Hopefully this mythical machinist can find a way to make each sprocket a single piece.

I kinda made reference to that possibility in this thread:
http://www.bonnevilleamerica.com/forums/...p;page=0#179524

That would be the MPB sprocket option, and would depend on the availability of sprockets in the desired dimensions.
Then there's the problem of getting splines broached.
Is there another way?
Dunno.

This duscussinon seems to be focused on replicating the QPD design.
According to what some have said, it appears that that design in turn is based around a Harley belt.
That's good in terms of availability, but is it optimal for this application?
Dunno.

If the belt could be wider and/or pulleys larger, that would contribute a lot to longevity.
Is this possible?
Does it mitigate the downside re: availability?
Dunno, dunno.

I think alternative tooth profiles are worth a look, too.
Goodyear eagle belts use what they call a helical tooth design.
It looks like the tread on a tractor tire.
The helical part comes in because the teeth run onto the sprocket smoothly.
Like the difference between a Borg-Warner T10 & an old Mopar singing 4 speed in reverse gear.
In this analogy, the blackhawk is "spur cut" like the mopar's reverse.

The belt is self-centering as it runs, so flanges are not required.
This could result in an ability to use a wider belt, because the width of the flanges has been saved.
Goodyear distributors sometimes state that they are stronger by virtue of having longer teeth for the same belt width.
I don't know that Goodyear makes this claim, though.

Downsides & potential show stoppers:
Pulleys are scarce & dear.
There may not even be a stock pulley small enough for the front.
The element of economy that's the focus of this thread may be sacrificed.

I think the biggest downside to using a wider belt is replacing the sprocket cover. Anything wider than the belt used by QPD and there should be interference with the cover. On the QPD pulley the side plates are no thicker than 1/16" so you're not gaining much by omitting them. A wider belt would probably interfere with the shock and/or frame. You can't go anymore inboard so the thickness has to be added outboard. I'm already running without the chain guard so no biggie there.

bump!!!

I talked with one machine shop and he said it would be cost prohibitive for him to make them much cheaper than Ozzie sells them for. He says it really is a lot of work, hence the big price tags. he told me about $700-800, pretty much the same cost. I still need to talk to another machine shop that specializes more in fabrication then motor work.
If it had transistors in it I could make em!

I would imagine anything that is round and has teeth is going to be expensive to make no matter what.... But maybe a shop that makes these kind of things for a Harley might be better off. But then again they all come with belts, so is there even an aftermarket for them?

they have kits for older sportsters

Frank

oh and i emailed oz and he never got back to me

Frank

Insult his integrity (or ask a question that seems like you're impugning his integrity, even though you're not, you're just asking a question). He'll call to scream at you within a couple hours.

Would love a belt drive. But the chain is no problem, with the Scott Oiler, I rarely think about it.

It would have to be real cheap to justify the change.

Hmmm. Its safe to say we wont get a response to emails sent to him on this matter.

sadley i will still prob order one

Frank

ok boys if I can get from someone CAD drawing then I know where to ask and important thing what type of metal has to be used I've been advised that PA6 (non welded hard alu)and I think price could be more than right but need drawings for another step

I'd be in for one if some one else starts making them. My biggest problem with the QPD is, for the price, it's kinda ugly. If some one else was making them at the same price but they looked better, that would be something to think about.

I would buy a belt drive if it run 2.33:1 gearing (42:18), and was cheaper... the gearing is the main thing I'm after because after running this with the chain anything else would feel way too small!

This could be done. I highly doubt we would be dealing with any type of patent infringement issues. It's very simple: there are belts out there, they have specific teeth geometries, our bikes have specific bolt hole patterns front and back, gearing is an issue of geometry (ratio of one gear/sprocket/cog to another), belt width and frame/cover clearance issues need to be taken into consideration. It’s a matter of getting the dimensions, drawing the stuff up (of course always considering manufacturability issues), ensuring you are using proper materials, finding a machine shop with the right equipment, buying some hardware and voila (spit).

Umm, now that I have gone through this thought process, $700-$800 does not seem all that crazy for what needs to be done to make these dam things. Perhaps I’ll have to do a one off and see how that goes.

Was talking about belt drives with a friend of mine today.
(yes I have one or two of those)

He's doing a chop job on his sportster, going to convert it to a chain drive. Said he'd give me his old belt drive in exchange for some manual labor and a bit of machine work.

I'm gonna see if I can adapt the snortster drive to America,
If successful and I dont wreck when done I'll post some detail drawings.

Dont anybody hold your breath waiting this could take forever.

I went to his shop an picked up my belt drive.
he really is an cool old dude to talk to( listen to ),
I think he is in his 70's.

Hello Again !!
So I guess I'm the guy who opened this old can of worms again! I'm glad I'm not the only one with these same apprehensive thoughts! Good luck to all who are going to try and come up with a solution.
I feel obligated to let you know where I stand on this....I may well buy one in the future if the project is successful. I can't commit financially because I need to do something right now. I am guessing this will take more than a couple months. My winter is over here in early April, so I need to get the rag out and buy something for the old girl. The other factor is the carrot that Triumph is holding out for us about the "Rocket Two", I've been patient and had almost given up, but now I'm hearing "probably for sure" next year. So I don't want to spend too much money on this old Black Beauty.
Guess I'll just replace the chain and sprockets for now. Think I will use a JT brand x-ring 530 chain. About 2/3 the price of the dealer kit.
I am also planning to order the VTS visors and the memphis shades lowers. Any thoughts??

I envy a lot of you guys who can ride all year long!

Gerry.