Hand Throttle

May 1998

Background | Installation | Cost | Postscript

Background

On bumpy trails it is very hard to keep an even pressure on the accellerator. Each bump causes my foot to bounce on the pedal and makes a bad ride worse. By installing a hand throttle, I can avoid this situation. The hand thottle will also help in a lot of other cases as well.

• Poor-man's cruise control
• Hold higher RPM for better volume from On-board air
• Set a constant pace for climbing steep hills
• Provide finer control of speed in any situation

Installation

The hardest part of the whole project was finding an appropriate lever to use for the hand throttle. I had seen some people use bicycle brake levers, but I wanted something that I could set and not have to hold in place. I had also heard of using a bicycle shift lever. That seemed like a good solution, but finding one was difficult. Most bikes now use fancy shifters with click-stops and buttons. I wanted something that I could quickly get back to idle to avoid the dangerous situation of being stuck at high RPMs.

I finally found a lever that had click-stops but that moved through the full range of motion easily. I used the built-in tubing clamp to mount it to my gear shift lever just below the knob. I mounted it so that in the center of its range, it pointed straight up at the knob. It has a 180 degree range. In this position, all the way one way pointed forward, and all the way the other pointed backward.

I then ran the cable and sleeve down the shift lever, loop up to a hole in the center of the firewall, and then to the carburator. I used electrical tape to fasten the cable to the shift lever, and a cable clamp to mount the sleeve next to the place where the accellerator pedal cable attaches.

The next step was to attach the cable to the throttle linkage. I found a lawnmower linkage swivel at Ace Hardware that worked perfectly. I drilled a hole in the linkage to accommodate the swivel. The cable passes through a small hole in the swivel and is clamped in place by a set screw. I adjusted it so that when the hand throttle was straight up, it was at idle. All the way forward was full throttle, and all the way back just put slack in the cable. This allows me to push it all the way back to get it out of the way when I am not using it. When in use, it is easy to adjust with my thumb while my hand is on the gear shift knob. It gives me very precise control over the throttle setting.

Cost

Postscript

5/31/98 - My first trail run with the hand throttle was great. It made life so much easier in a lot of circumstances. It also made the drive to the trailhead more enjoyable. I was able to set the "cruise control" and sit back and relax.