spurlock
New Member
I recently bought the Harbor Freight motorcycle tire attachment #60810 which mounts to the Harbor Freight "manual tire changer #69686" and thought I would share my experience with making it actually work. I've always just used tire irons even for car tires but now that I have a bike with alloy rims I see the advantage of a mechanical changer.
The motorcycle attachment is completely non-functional as delivered, but with simple modifications makes a very decent tool. The basic HF tire changer works great as a bead breaker for all kinds of tires including cycle tires. But the motorcycle attachment that goes on it was apparently designed by someone who never tried it out. The good news is there are three basic problems, all easily fixed:
1. The rim clamps are bare metal which will scratch painted or alloy rims. Solution: order a set of "mojo blocks" here:
http://home.comcast.net/~prestondrake/mojoblocks.htm. These poly attachments hold the rim securely without scratching. I made my own plastic blocks since I do plastic machining and have lots of scrap, but the Mojo blocks are cheap enough at $30 incl. shipping. Notice that the clamps automatically push the lower tire bead up into the rim's drop center so you don't have to keep squeezing it up by hand.
2. The motorcycle attachment comes with an approx. 1" spindle that is supposed to run through the motorcycle hub and screw into the tire changer, see first photo above. There are two problems here. First, two of the rim clamps are fixed in position and the third is screw adjustable for clamping. So when the clamping screw is tightened the wheel is pushed off center and the spindle would not line up with the threads in the machine. Besides that the spindle is too big to fit through most motorcycle wheel bearings anyway. Solution: The spindle does not need to screw into the tire changer, it only needs to go into the top hub bearing. Since the rim is clamped in the machine the hub bearing is a solid anchor point for the spindle which is only used as a pivot point for the tire mount/dismount bar. So you can just substitute a 5/8" rod for the HF spindle. For smaller bearings just put a 5/8" by 1/2" motor arbor on the shaft, like you would use to mount a 1/2" bore wire wheel on an electric motor with 5/8” shaft. The vertical and horizontal arms that hold the top of the spindle have plenty of slop to move off-center, so the substitute bar can easily align with the off-center hub bearings.
I machined a polyethylene bushing shown below for the 5/8" rod, but another option would be a short piece of Sch 40 PVC pipe with PVC caps on each end, with the caps drilled to fit the rod.
3. The mount/dismount bar that comes with the basic HF tire changer is too crude to use on motorcycle tires. But there are at least two aftermarket bars that work great: the Mojobar (http://home.comcast.net/~prestondrake/mojoweb.htm) and the No-scuff tire tool (http://www.no-scufftiretool.com). Below is the Mojo bar dismounting end with a low-friction scratch free nylon end:
Here the first bead is being removed:
And here the bottom bead comes off:
The other end of the Mojo bar has the tire mounting hook, again with non-scratch nylon:
The bottom line is I find the modified HF changer works really easily, avoids scratching the rims and tearing tire beads. And being older now I much prefer working while standing to kneeling on a motorcycle wheel on the floor. Try it, you'll like it.
-Bill
The motorcycle attachment is completely non-functional as delivered, but with simple modifications makes a very decent tool. The basic HF tire changer works great as a bead breaker for all kinds of tires including cycle tires. But the motorcycle attachment that goes on it was apparently designed by someone who never tried it out. The good news is there are three basic problems, all easily fixed:
1. The rim clamps are bare metal which will scratch painted or alloy rims. Solution: order a set of "mojo blocks" here:
http://home.comcast.net/~prestondrake/mojoblocks.htm. These poly attachments hold the rim securely without scratching. I made my own plastic blocks since I do plastic machining and have lots of scrap, but the Mojo blocks are cheap enough at $30 incl. shipping. Notice that the clamps automatically push the lower tire bead up into the rim's drop center so you don't have to keep squeezing it up by hand.
2. The motorcycle attachment comes with an approx. 1" spindle that is supposed to run through the motorcycle hub and screw into the tire changer, see first photo above. There are two problems here. First, two of the rim clamps are fixed in position and the third is screw adjustable for clamping. So when the clamping screw is tightened the wheel is pushed off center and the spindle would not line up with the threads in the machine. Besides that the spindle is too big to fit through most motorcycle wheel bearings anyway. Solution: The spindle does not need to screw into the tire changer, it only needs to go into the top hub bearing. Since the rim is clamped in the machine the hub bearing is a solid anchor point for the spindle which is only used as a pivot point for the tire mount/dismount bar. So you can just substitute a 5/8" rod for the HF spindle. For smaller bearings just put a 5/8" by 1/2" motor arbor on the shaft, like you would use to mount a 1/2" bore wire wheel on an electric motor with 5/8” shaft. The vertical and horizontal arms that hold the top of the spindle have plenty of slop to move off-center, so the substitute bar can easily align with the off-center hub bearings.
I machined a polyethylene bushing shown below for the 5/8" rod, but another option would be a short piece of Sch 40 PVC pipe with PVC caps on each end, with the caps drilled to fit the rod.
3. The mount/dismount bar that comes with the basic HF tire changer is too crude to use on motorcycle tires. But there are at least two aftermarket bars that work great: the Mojobar (http://home.comcast.net/~prestondrake/mojoweb.htm) and the No-scuff tire tool (http://www.no-scufftiretool.com). Below is the Mojo bar dismounting end with a low-friction scratch free nylon end:
Here the first bead is being removed:
And here the bottom bead comes off:
The other end of the Mojo bar has the tire mounting hook, again with non-scratch nylon:
The bottom line is I find the modified HF changer works really easily, avoids scratching the rims and tearing tire beads. And being older now I much prefer working while standing to kneeling on a motorcycle wheel on the floor. Try it, you'll like it.
-Bill
