Just finished testing the two-speed drive on the HF 99 CC motor. Removed the drive and installed on a stock Q-Matic drive on a HS 142 49 CC 4-stroke motor for future testing. We designed it to become an upgrade to the stock Q-Matic drive, therefore I only had to change a few parts, including an additional clutch and inner bearing support bracket. I was surprised how easy it was to install on the existing Q-Matic drive.
Sadly we still haven't been able to find a fabrication shop willing to make it for a reasonable price, but we are still shopping. One of the issues we encountered are prices for a low production run. I thought using the stock Q-Matic drive plate, bearings, belt, Max Torque clutch, and rear bearing support would help the mfg cost. However the current issue is making the front bearing support [approx. 2" wider], special modified secondary Max Torque clutch and we haven't even addressed the wider cover needed.
We will continue with the project and may even make a small run of "limited" edition prototype drives for testing while we continue searching for the right shop to make the upgrade system.
The Q-Matic II simply adds a much lower ratio [or higher depending on point of view] to the stock ratio to allow quicker take-off speeds and will handle tough hills much better. It has been a lot of fun tuning the drive to shift where you want it, and working with low RPM motors [HF 79 & 99 CC].
Here is how we configured the drive to work with the low RPM motors:
Installed 2 larger primary pulleys, and 2 types of drive belts. By using a stock primary pulley [used on the stock Q-Matic] on the inside, and a slightly larger on the outside, and altering the belt type, we start out with approx. ratio of 15.5 X 1, and then shift to 11.5 X 1. Of course one of the Max Torque clutches is the stock Q-Matic version, and the other has a reversed operation, different shoes, and spring rates. As soon as we spin the shaft at a high enough RPM the primary clutch enguages, then at a higher RPM speed the secondary clutch over rides the shaft speed and spins the primary clutch at the new ratio.
Have fun,
Sadly we still haven't been able to find a fabrication shop willing to make it for a reasonable price, but we are still shopping. One of the issues we encountered are prices for a low production run. I thought using the stock Q-Matic drive plate, bearings, belt
We will continue with the project and may even make a small run of "limited" edition prototype drives for testing while we continue searching for the right shop to make the upgrade system.
The Q-Matic II simply adds a much lower ratio [or higher depending on point of view] to the stock ratio to allow quicker take-off speeds and will handle tough hills much better. It has been a lot of fun tuning the drive to shift where you want it, and working with low RPM motors [HF 79 & 99 CC].
Here is how we configured the drive to work with the low RPM motors:
Installed 2 larger primary pulleys, and 2 types of drive belts. By using a stock primary pulley [used on the stock Q-Matic] on the inside, and a slightly larger on the outside, and altering the belt type, we start out with approx. ratio of 15.5 X 1, and then shift to 11.5 X 1. Of course one of the Max Torque clutches is the stock Q-Matic version, and the other has a reversed operation, different shoes, and spring rates. As soon as we spin the shaft at a high enough RPM the primary clutch enguages, then at a higher RPM speed the secondary clutch over rides the shaft speed and spins the primary clutch at the new ratio.
Have fun,
Attachments
Last edited: