Belt drive of unknown brand

Kvinnhering · Oct 24, 2017

Hello.
Can anyone tell me what belt drive this is?

Is it possible to buy clutch plates and belt for this set and who sells this?
Does anyone have experience with this kind of belt kit, good and bad.

marinatlas · Oct 24, 2017

Hi, just my opinion, but it could be a QPD .............???

dynodave · Oct 24, 2017

http://www.quietpowerdrive.com/QPDhtm/QPDhome.htm

Kvinnhering · Oct 24, 2017

Thank you for your prompt and good feedback. Any experience with this kit? Based on their website, this seems to be okay kit.

swooshdave · Oct 24, 2017

Kvinnhering said:
Thank you for your prompt and good feedback. Any experience with this kit? Based on their website, this seems to be okay kit.

Good luck getting ahold of them.

Kvinnhering · Oct 24, 2017

swooshdave said:
Good luck getting ahold of them.

Thanks again

Chris · Oct 24, 2017

Hi Kvinnhering

Tony Hayward I have 2 of his clutches 10 pin & 12 pin. Plates are standard with semi circular holes cut in the edges. He usually has stock but they arn't hard to make.

all the best Chris

rotorwrinch · Oct 24, 2017

Kvinnhering said:
Hello.
Can anyone tell me what belt drive this is?
View attachment 3116

Is it possible to buy clutch plates and belt for this set and who sells this?
Does anyone have experience with this kind of belt kit, good and bad.

It looks like the engine and the clutch basket have a different tooth form. The engine has what appears to be a round tooth form and the clutch basket has what appears to be trapezoid form. Maybe just the photo view. Have you measured the pitch? It looks like 8mm pitch, but the trapezoid form is more common in 10mm pitch. Although manufacturers may guide you away from mixing round based 8mm pitch belts, many tooth forms can be used on many of the sprockets. Many manufacturers list their products on line. Common conventions can be purchased in a variety of lengths and because they are extruded, any width within reason. Tensioner material and the composition of the belt are other considerations.

I became an outhouse expert several years ago when building a belt drive primary for a road racing Commando. One thing I learned was to not share with belt suppliers what I was doing with the components. Seems that in the US, liability issues place motorcycle projects in the same category as airplane projects.

Brooking 850 · Oct 24, 2017

ROTORWINCH, I am running Steve Maney belt drives in both my 850's. Road bike is 30 mm and race bike is 40mm
I found that some suppliers off the shelf belts are designed for static electric motors, big fans etc.
Suppliers like Optibelt have ones for high torque loads (off on and on) as in our race bikes , although more expensive.
Just a bit of info from my experience and research
Regards mike

jseng1 · Oct 25, 2017

Yes that is a QPD - the 1st belt drive available for Nortons and it came out in the early 1980s. It came out before round toothed belts were available and the square toothed belts were weak and failed. I got one 2nd hand back then from Ken Canaga and converted it to round tooth by mounting a shortened round file in a die grinder and spent a few hours reshaping the teeth. With a 40mm round toothed Gates/HTD type belt I had the 1st reliable belt drive on the tracks. Believe it or not I'm still using it on the street today but I've replaced the crank pully and have maintained it with bronze plates (turned down on the OD).

If you use it be sure to centerpunch the countersink screws on the clutch basket to keep them from spinning out. Good luck with fitting a belt.

baldy · Oct 25, 2017

It is a QPD. I have one on my bike.I talked to Bob Oswald about a year ago. He is still in business. You need special plates and a special belt from Bob. Reality is easier to scrap and spend 400$ for a Norvil or RGM belt drive.

G81 Can Cycle · Oct 26, 2017

Might take a look at CNW belt drive. It is a stand alone belt drive using components from CNW's Electric Start Conversion. Uses a composite belt (poly carbon) at only 21 mm wide. It's a Gates belt rated for 100 HP. The clutch basket is aluminum and accepts standard Commando clutch plates We ran 2 of these belt drives on Stan Keyes racing Commandos all year with no failure (20 races and 60 to 70 practice sessions)

My shop makes the drive, so I am admitting bias. But look at it any way if you would like to see another offering than ones mentioned above.

https://coloradonortonworks.net/part-categories/cnw-primary-final-drive.html

Matchless · Oct 26, 2017

At 21mm belt width it would be good for Dominators & many other old Brits where space is a problem. Is the tooth form the same as used by Maney & Norvil ?

Kvinnhering · Oct 27, 2017

G81 Can Cycle said:
Uses a composite belt (poly carbon) at only 21 mm wide. It's a Gates belt rated for 100 HP.

Hi.
Is it possible for you to specify the tooth profile and the pitch of the 21 mm wide toothbelt? Maybe it could fit my kit?

Would like to thank you all for good feedback in this thread.

lcrken · Oct 27, 2017

More info on the Gates Poly Chain GT Carbon here:

http://www.gates.com/products/indus.../synchronous-belts/poly-chain-gt-carbon-belts

You can download the design manual for these belts at the bottom of their page.

Ken

jseng1 · Oct 27, 2017

Matchless said:
At 21mm belt width it would be good for Dominators & many other old Brits where space is a problem. Is the tooth form the same as used by Maney & Norvil ?

No the poly belt won't fit very well on conventional Norton belt drives because the belt teeth will bottom out on the sprocket. The poly belt is very strong and should work well but its doesn't have the shock absorbtion qualities of the HTD style belt. In other words - the poly belt is similar to running a steel chain where the common HTD belt makes life easier on the tranny. I've blown up more trannys that engines so the shock absorbtion is important to me. But when space is a problem you only have the choice of poly belt or narrow chain. Gates does not recommend the poly belt for motorcycles (they recommend HTD belts) but that doesn't keep people from using polychains on Harleys or elect start Norts.

madass140 · Oct 27, 2017

"but that doesn't keep people from using polychains on Harleys or elect start Norts."
or even rear belts on Nortons.

Fast Eddie · Oct 28, 2017

As Commados have a SA in the rear wheel as standard, even if it is a less than optimal design, I doubt the need for extra SA ability in the belt.

jseng1 · Oct 28, 2017

Where is the rear wheel polybelt kit? There's a project for you G81 Can Cycle. Send me one that fits and I'm be happy to test it for you (so would everyone else).
Shock absorbtion is one of the features touted by the Norton primary belt suppliers. If it was only useful on one end then you could run a shock absorbing belt on the primary drive and swap the heavy rear wheel shock absorber design for a lighter Rear wheel. This is what I did on my roadracer but I still blew gears. Probably would have blown gears with shock absorbtion on both ends.

lcrken · Oct 28, 2017

I thought we had established some years ago that the belt primary drive doesn't really provide any more shock absorbing than a chain primary. The real benefits of the belt drive are less weight, dry clutch, and the ability to easily run a higher primary drive ratio. The higher primary drive ratio is what reduces the loads on the gearbox, not shock absorbtion. Just my humble opinion, as usual.

Ken

Belt drive of unknown brand

Similar threads