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Q-talk 85 - Using MATCO Mains

 

Bud Starns, ML Vernon, IN

Hello David,
Congratulations on being our new Editor-in-Chief, the following is an article that I was going write for Tom, sorry Tom, but you are the victim of my computer instead.

After re-aligning the main gear, ala David Gall’s article, and thanks David for your help, I tried to install the original 1 100X5.OO wheels and brakes and the tires were at such an angle that the tire was rubbing on one side and the rotor was rubbing on the other side. After I looking the wheels over very carefully, I decided that I was either going to have to cut offthe entire wheel pant and realign them again, or find a smaller tire and brake combination that would give me the clearance that I needed between the wheel/brake assembly and the inside of the wheel pant.

After talking to Tom Moore and Bob Malechek, they suggested using the Matco W50SB units. I called Matco and got the information on these wheels and checked their website out, and decided to use these on my Q200. Bob also mentioned that these units are nearly trouble free compared to the Hearst/Airheart units that came with the kit, as an option.

I purchased them thru Chief A/C and got them shipped direct to me from Matco. The W50SB do not come with tires or tubes, so I ordered them from Greenball Tire Co in CA. The tires were priced at 15.95 each, and the tubes were 3.95 each. I talked to several Q Guys that had converted to the Matco units, but couldn’t find anyone that had taken pictures of their installation, so I decided to try to document the installation as best I could for someone in the future that might run into the same problems as I had with the H/A units.

The caliper-mounting bracket comes with a 1/2” hole and that had to beenlarged to 5/8”, which is the axle OD. I slid the axle thru the wheel pant holes and wheel and brake caliper and centered the wheel in the opening. I needed a spacer 1.5” between the rim and outside wheel pant and another 1.5” spacer between the rim and caliper mounting bracket, and 1/2” spacer between the bracket and the wheel pant on the inside wall.

Bob Malechek said he had bolted thru the wheel pant into the bracket to stabilize the bracket to the wheel pant with two AN bolts. I felt that if I triangulated the bolts, there would be more strength and so I used two AN3 bolts and one AN4 bolt. The spacers were made from .125 wall X 5/8” ID tube, trued in a lathe. Assembling everything together and drilling the holes for the mounting bolts in the wheel pant with a pilot drill (smaller than 3/16”), I removed the entire unit and drilled and tapped the three holes, with the proper size tap, in the bracket for the caliper.

Photo #1 and #2 show the mounting pad that I made and the three mounting holes, also notice that I moved the brake line to the inside of the wheel pant to it out of the slipstream. The large pad is epoxy and flox with the bushing providing the axle hole and positioning the caliper bracket at the correct distance from the wheel pant.

I put shipping tape on the side of the bracket and floxed the bushing in place. I then made a template of the caliper unit to use as a guide for the hole in the wheel pant for the caliper to be able to slide laterally during application and transferred it to the pant using the axle hole as a reference.

Photo #3 shows the finished hole with the axle and mountng bracket bolt holes. The small holes around the perimeter are for the caliper cover screws, see hoto #7.

Photo #4 shows the caliper unit mounted inside the wheel pant and photo #5 is outside of the same. Photo #6 shows the right wheel and rotor mounted in the pant.

The caliper cover was made by using 3/8” Clark foam and laying two layers of BID over it. I glued the foam to the wheel pant after covering the surface with shipping tape and glassed directly to the pant. I didn’t remove the foam after curing so that it I would add a little more rigidity to it, but it probably could be removed.

Photo #8 is the complete assembly with the cover in place.

I had the airframe upside down and it sure simplified the process a bunch. If anyone has questions, they can e-mail me This email address is being protected from spambots. You need JavaScript enabled to view it. or I can be reached by phone at 812.985.2527.

5114 HartmannRd.
Mt. Vernon, IN 47620


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