Q-Matic II 2 speed

Quenton Guenther

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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,
 

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That's pretty neat but boy it looks kinda wide. How much wider do you think the production version of this will be than a standard Q-matic? I'm hoping not much.
 
Hi Abikerider,

Bill is correct it is approx. 1.5" wider than the stock Q-Matic drive. It is important to note that the stock Q-Matic is one of the thinnest drives available, and can be even downsized a little more. We ship the Q-Matic with a cover that is 2" deep, however it can be cut down another 3/8" and still clear all the internal parts of the drive. We use a 2" cover to allow more space inside to keep the parts cooler.

On the stock Q-Matic, there is a space between the secondary drive pulley and the clutch, that is occupied by the second primary drive pulley on the Q-Matic II.

Good news is the wide part of the drive is normally behind the left leg in a normal riding stance.

Have fun,
 
WOW very intresting. Sounds like what everyone has been waiting for.......Curt
 
Hi Quenton
You should get your 2 speed out to the SoCal races.
Win races on Saturday and sell on Monday? :D

Affordable Go Karts raced a 79 cc HF with their 2 speed at the last
Oct 22nd SoCal Motor Bicycle Race.

The 79 cc HF 2 speed was keeping up with the 5 HP Briggs bikes but
the rider went off the track and stalled so he didn't end up beating
them. Actually that happened a couple of times and he was still able
to catch up!

Shane's (AGK) son will probably be racing it again on a 99 cc HF Predator
at the next April 7th race and it should be for sale soon.
 
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I'm very much hoping this can become a reality for the rest of us. This summer I plan to switch out the H.S. engine for the 99 Predator simply because as it is my Panther can't pull the hills adequately. If I thought the 2 speed was going to happen I wouldn't bother changing engines. The H.S is sweet running and easy to start. If you need a tester for the 2 speed, I happily volunteer.
SB
 
Hi everyone,

No doubt the Q-Matic II is a winner, however the cost is still an issue. We just received information from several companies that wish to bid on the project, hopefully we can "get-er-done" for a lot less.

Currently we are considering making a few proto-types for additional testing, but the cost is still very high. The main reason is the use of two Max Torque clutches, one as the primary and the second as the overdrive. Making a short run of wider bearing support brackets is another costly reason, and we may consider "welding" extensions on current brackets to save a few $$$.

Have fun,
 
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