Quiet Power Drive

Ever since rebuilding my 1972 Tr6 unit Triumph, I’ve always picked one thing over the winter to rebuild or do better based on my summer of riding.

Four years ago during the summer I had a small oil leak on the primary side and decided to try and install a dry primary I’ve seen on some Triumph choppers at a few shows.

After talking to a few folks and getting prices on multiple systems I settled on the QPD system developed and built by Bob “Ozzie” Oswald. In 1978 he built a 750 Bonnie belt system, which piqued the interest of Triumph in the U.S. and the Meriden factory. At the invitation of Triumph, Ozzie went to England where Bob demonstrated the reliability of his belt drive on a racetrack. This was the first of three trips to the U.K. but Triumph sadly shut their doors before a deal could be struck.

So needless to say the system has some history behind it and some old school cool. And that is what I was looking for.

I called and actually talked to Mr. Oswald, who was a very nice gentleman and answered all my questions. I ordered it there on the phone, and about 4 weeks later had a hand built system delivered to my door.

That system which consists of a QPD Aluminum Alloy Drive Pulley, QPD Aluminum Alloy Clutch Basket, QPD Aluminum Alloy Clutch Center Hub, QPD Plain Clutch Plates, QPD Clutch Pressure Plate, QPD Diaphragm Clutch Spring, Barnett Friction Clutch Plates , Gates HTD Toothed Belt, and all the necessary fixing hardware.

QPD clutch kit

QPD clutch kit

I won’t get into the details of the installation in this article (send me an email if you want details), but it was very easy.

Removed the old primary and recharging systems, JB weld the oil holds (instead of using the sheet metal screws that came with the kit), to ensure no oil would lead into the primary. Followed Ozzie’s instructions, a phone call was needed for this part due to the fact the system showed up without instructions. Even with that little issue, the system was on in less than 3 hours (after the JB weld hardened).

I continued the customization by putting spacers on the cover and machined out the cover so you could see the clutch. Sort of my ode to Ducati dry clutches.

Issues were few, one was I didn’t know I was going to need a clutch tool. but you can purchase a Norton Clutch tool or build one like I did with some steel pipe, flat stock, large bolt with matching threads to the plate.


This puts pressure on the pressure plate to allow you to get the snap ring in place to keep the pressure plate in the clutch basket.

The other issue was my fault; I didn’t use blue thread lock on the tension screw that’s in the middle of the pressure plate. So after a few rides I lost the ability to use the clutch due to loose parts. Tightened it up and I’ve been good to go ever since.

IMG_5131 IMG_5130

Conclusion: I don’t think I’ll rebuild another triumph motor without one of these. Has never failed me. No more oil leaks from that cover. And the power delivery is nuts! I’ve never tried or used any of the other less expensive dry clutch conversions that folks like MAP and British Cycle Supply sell, so I can’t say it’s better, but it was easy to install and hasn’t failed me yet.



For more information see the QPD website.


This winter maybe adding a hydraulic clutch conversion, to get rid of the clutch cable and give my forearm a break in traffic.