Testing the 79 & 99 CC HF motors

[azbill]

thanks for that info
looks like it will be approx 5k for my 72tooth @30mph
(I don't plan on taking her any higher than 5k rpm's)

 

[Quenton Guenther]

Hi Bill,

The HF motors appear to do fine below 6000 RPMs. The only issue I have found is the partial plastic flywheel wants to cause problems above 6000 RPMs for an extended period of time.

I would think 5000 RPMs would be a safe limit for the motor.

Have fun,

 

[Deleted Member 4613]

I do have a concern about safety when mounting a larger engine on a bicycle frame, and of course, such designs are not legal in most states.

 

[Richard H.]

I do have a concern about safety when mounting a larger engine on a bicycle frame, and of course, such designs are not legal in most states.

I agree, frame tubes and welds, wheels, bearings, brakes. This is to say nothing of the legal aspects or lack thereof nor the aspect of public perceptions morphing basically benign power assisted bicycles into small motorcycles.

 

[Deleted Member 4613]

Probably, when the motor/power gets to be too much, too high, a motorcycle designed from the ground up with a heavier frame and disk brakes would be much safer.

 

[Gen3Benz]

How much are the q-matic drives?
I cant find the price on your website.

edit: clicked on jbcruisin's link and found the price, neato looking kit

 

[jbcruisin]

How much are the q-matic drives?
I cant find the price on your website.

edit: clicked on jbcruisin's link and found the price, neato looking kit

Hit the link in my signature here.

 

[gphil]

HF engines

I did not purchase a new engine 99 cc because of the concern of the drive side ie 58 versus what ever it was. I plan on getting one but they are going on sale again in March. Right now 99.99 May get one anyway. Just do not want to have to fabricate a bunch of parts, unbox and install is my best game at my age. Let me know. Love these posts learning loads. gphil

 

[Quenton Guenther]

Hi gphil,

The Q-Matic has been designed to be a simple "bolt-on" item for the HF 79 & 99CC motors. We have supplied a fair amount [less than 50], and the reviews have all been 100% positive.

There are other ways to attach drive parts to the HF motors, but the end cost is about the same, requires more time & labor, and just doesn't work as well as the Q-Matic drive. You can purchase a clutch, drive plate, jackshaft, bearings, pulleys [or chain sprockets], belt [or chain], cover, and misc. bolts & nuts, and get it to work.

Here are some details that might be of interest to you:

There are 2 ways to install the clutch, one is directly on the motor crankshaft, and another is to locate the clutch on a secondary shaft [jackshaft].

There must be a secondary shaft [jackshaft] with either system because of the necessary reduction from the motor to the rear wheel.

If you install the clutch on the motor, it is important to note the power loss. It simply takes more power to spin a clutch at full motor speed as it does to spin it at approx. 1/3 motor speed. Spinning the clutch at full motor speed also slows down the rate of acceleration, as the motor just doesn't need more "flywheel" action. Less "flywheel" action also increases the rate of de-acceleration [motor braking], and helps the bicycle brake to last longer and run cooler.

If the clutch is mounted on the motor crankshaft, all the parts except the clutch shoe assembly must turn when the clutch is disengaged and the bicycle is in motion [called freewheeling], whereas only the rear chain and clutch "bell" turn if the clutch is mounted on the secondary jackshaft during freewheeling.

This explains why the Q-Matic is so much faster, and transfers more power to the rear wheel than other drive systems and requires a lot less power from the motor to operate.


Hope this information is helpful.

Have fun,

 

[Mr.G]

I hope you have better luck with the 99cc than I have . The carb has no adj. and it does not idle and has sttoped for no reason. It does not sound good at all. Mr.g...