I’ve been using the Harbor Freight manual tire changer w/motorcycle adapter for a number of years now, and though it’s not perfect, it is quite serviceable especially when one usually works alone like I do.
One challenge with this unit though is the steel clamps designed to hold the rim secure, can damage the rims. I’ve used various methods over the years to minimize this risk, including duct tape and pieces of inner tube as have others evident by the postings regarding this on the Internet. Some folks have even made their own replacement clamps or blocks, usually out of a hard plastic.
Since I was facing mounting the rear tire on the project CB750K Honda, which will be a bugger no matter what, I was looking around the ‘net for a decent solution to this steel clamp issue. I knew I was going to be fighting the tire so I wanted to minimize wrestling with the tool itself (changer) and I wanted to do something about the clamps.
Eventually I found the “Mojoblock” replacement clamps, which an enterprising individual decided to make available to solve this very issue. I thought I’d give the clamps a try, so I ordered a set.
What you get in the kit are three machined white plastic (nylon?) bolt-on clamps, drilled and countersunk for the fastener heads, three stainless steel Allen head bolts with flat washers and nylock nuts. There are three of everything as there are three clamps on the tire changer.
The Mojoblocks are well made, with the the contour, shape and radius of the clamping face perfect for the CB750K rear rim I used them on for the first time. Installation is very straight forward…
- Remove the OEM clamps from the tire changer
- Locate new block in position on top of original clamp
- Dill pilot hole and 5/16 finished hole for through bolt
- Attach new clamp to top of original clamp with provided hardware
The whole operation took maybe 15 minutes. I did deviate from the on-line instructions though. Instead of measuring from each clamp edge to locate the position of the pilot hole, I simply located the new block on top of the clamp with may fingers and used a fine-point Sharpie market to mark the location of the pilot hole. This worked fine and saved a little fiddling around with a tape measure or square.
The clamps are not particularly inexpensive at $30.00 for a set of three (including postage), but unless one has access to a mill, the raw material and wishes to invest the time in setting everything up to make three clamps, it’s a fair deal and a good investment. Bottom line… these replacement clamps are well made, are supplied with quality hardware and delivery was quick so I’m quite satisfied.
Also note, there are apparently three different types of rim clamps Harbor Freight ships with their tire changer, so Mitch at Mojoblocks supplies different versions of his clamps to accommodate whatever style OEM clamp your changer has. One has to order the appropriate Mojoblock to match their OEM clamp style.
And oh, by the way, I did have the new clamps installed on the tire changer when I installed the replacement tire on the C750K. They held the tire nice and secure with not slipping or marring…. perfect.
Mojoblocks Web Site: http://home.comcast.net/~prestondrake/mojoblocks.htm
Here’s a tip when changing motorcycle tires with tubes: add a few pounds of air to the tube before attempting to complete the mounting of the tire. This will pull the tube away from the bead of the tire/rim and make it less likely to damage the tube.
Below are a series of photos that illustrate the new clamps before, during and after installation on the tire changer. In the first photo, note the black circle w/arrow on the left. This illustrates the curved metal rim clamp these replacement blocks are designed to address.
