LSA Wheel and Brake Selection Guidance

[lsa140]

Wayne Massey listed the wheel, brake, and tire setup he is using on the LSA (I believe Bob's prototype and Mark's use this same setup as well) in a previous thread: http://bearhawkforums.com/forum/bear...sa-kit-started) Matco 8" wheel and brake with a 21" tire. Matco lists this setup as weighing 8.3lbs each. Matco doesn't list a tire weight, and I'm not sure if this tire is being run with tubes or tubeless? I'm guessing this tire/tube weighs 8-11lbs?

This combo is proven, light, and very affordable. The wheels are rated to 700lbs static a piece. The tires 410lbs.

For my application I would like to step up the strength/rating in the wheels, brakes, and tires while keeping as light as possible. The aircraft will spend a lot more time on remote strips, gravel bars, and beaches than improved runways. It will also likely be operated up to its 1500lb design gross weight.

It looks like I can run a lightweight 6" Grove wheel and brake setup at around 7.5lbs each and Desser Aero Classic 850-6 smooth tundra with tube around 12lbs each. This combination would be very close in weight to the Matco, with quite a bit more load rating. It would also allow for installing 26" or 29" Airstreaks down the road. (which use a 6" rim)

Would anyone that has flown the LSA be willing to share their impression of the braking authority that the Matco setup provides? I'd like to use this info as a reference in choosing the Grove brake setup. Using Matco's calculator, it looks like running 29s at 1500 gross would require over 60% more brake torque than the 1320 gross on 21s.

[Wayne Massey]

The Matco wheel, brake, and tire setup that I’m using is with tubes, same as Marks. The Matco setup has plenty of braking authority. I guess my main concern with that setup isn’t so much as not having enough brake authority but rather aggressive braking and the tire and tube slipping and busting off the valve stem and deflating the tire.

Bob told me that for aggressive STOL landings on grass he lands with the wheels locked up. He said, “you never see an airplane nose over on touch down but toward the end of the landing roll.” It works! (as hard as it is to try it the first time!) I’ve done it several times on wet grass but I’m a little apprehensive to do that on dry grass and potentially slip a tire and bust the valve stem off. The CG is aft of the main wheels enough that there is no tendency to nose over as long as you 3-point land. I normally 3-point land the LSA but with a 2-point main wheel, tail high landing it feels to me that you could nose it over with aggressive braking with the Matco setup.

I would add that the Matco brakes are in my opinion comfortably responsive, steady and predictable. I’ve taxied Marks LSA in 25 mph winds on pavement and the brakes are very effect with differential braking to maintain directional control.

The lightweight 6' Groves and Desser Aero Classic would probably be a good set up too

[lsa140]

Excellent info Wayne, much appreciated.

[Clint B]

In my opinion, the Matco wheels are plenty tough beyond the 700 lb per wheel limit. this is the same wheel that just used on their prototype superstol, and I never heard of them breaking or bending anything, and they were slamming that thing into the ground pretty hard.
When I put the 27" dessers on my cub, I did have to go to the E series brakes that have the double calipers, but the brakes were adequate for 8:50-6 with the single calipers.
As to shearing off a valve stem, you can install the tubeless kit, which by putting an o ring between the wheel halves eliminates the need for a tube and saves about 4 lbs.

[lsa140]

I'm familiar with the Superstol, but had no idea they were running Matco. Looks like they use the double caliper setup you ran when going to 27 inch Dessers. How did you like that setup?

Interesting, I emailed Matco with the specs of the Bearhawk (1500 gross) and asked if that series of rims was sufficient. They responded only with 'The MHMHE8B-SC is rated at 700 lbs static load per wheel'

I would think the tailwheel would be bearing at least enough weight for the rim spec to match the LSA flown at 1500.

[lsa140]

Now I am curious about running the 6" matco wheel, with a single caliper, and provisions for adding the second caliper when going to the 29" airstreaks.

Clint B do you know if the various sizes of Matco MH series rims would go on the same axle/brake setup? Could you mount a set of 850s on 6" rims, and quickly swap 8" or 10" rims?

Here is the superstol with 6" matco, double calipers, and 29" airstreaks.

[Clint B]

I have run both the 6" and 8" wheels on my cub. They are interchangeable as far as the axle and brakes are concerned. You will want to order the long spacer kit from Matco though. The bigger tires will be to close to the brakes and need the spacers to move the brake disc inboard and give the clearance. You Definetly want the clearance from the bleeder valve to the tire. A hard landing will squash the tire out and into the bleeder valve and cut a nice ribbon out of the side of your tire. Don't ask me how I know this! I felt that the single brakes were adequate on 8:50-6 but not enough for anything bigger. If you are thinking seriously about putting the bigger tires on eventually, I would Definetly start out with the dual brakes. The holes on the torque plate aren't drilled so it wold be easier to do this before you have the plane flying.

[lsa140]

Thanks Clint B , this is all great information.

The big tires will definitely be going on, so if I go with Matco I'll setup for dual caliper from the start.

What where your impressions of running the Desser 27" tubeless? I'm just wondering how well the bead remains sealed to the rims and retains tire pressure. The cost savings over Airstreaks is attractive, but do the Desser's consistently perform well in adverse conditions? (cold weather, rough terrain)

The tubeless Dessers have a lot of seams that need to remain air tight (between the wheel halves, and tire beads.) The Bushwheel in comparison has only the tire valve.

[marcusofcotton]

On various lawn mowers I've had tubeless tires, not unusual to have troubles with bead leaks at low pressures I like to run at. I sure like the idea of the tubeless in regards to weight and valve stem issues.

[whee]

I read on another forum that the tubeless wheel with Desser tire seems to leak down a little. Think I'd try the tubeless with Stans NoTubes and if that didn't work I'd just run tubes.

[lsa140]

Thanks for the tip, sounds like a great product.

[Clint B]

My experience with the 27" dessers was really good. The guy who bought my cub hasn't really used it that hard, but has had no issues whatsoever with the tires. To be fair' the ABW's are the ultimate off airport tires, I've had those too, but at well over 1000$ a piece, I just couldn't justify them, and the thought that every pavement landing was scrubbing off several $$ of rubber didn't help either. At 400$ per the dessers are replaceable without breaking the bank.
Another local guy also has had them on his cub without any issues whatsoever for about a year now.

[lsa140]

Clint B What kind of air pressure did you run in the Dessers? It sounds like the rubber is reasonably soft, just wondering how low they could be run tubeless.

[Clint B]

It seems like I ran 8-10 psi. I think the biggest potential problem this tire has is that you could knock ot off the bead if you turned to hard going fast. The ABW's obviously won't have this problem.

[lsa140]

Understood, thanks for the info Clint.

[lsa140]

After the input here and doing some additional research online I'll likely move forward using the Matco MH series wheels/brakes. Initially the 6" wheels will be installed with Desser 800-6 4 ply tubeless tires (21") This will require running a .375" brake rotor spacers to clear the larger tire. I will be ordering the second caliper kit, and prepping the mount flange during construction. Initially only one caliper will be run to get familiar with the braking power, and to keep things light.

To run the .375" rotor spacers, brake plate spacers will need to be added to the inside of the axle mounting place, with the brake plates run inside of the spacers. You could also built the axles to accept the additional rotor space. On the 6" wheels the brake caliper rests very close to the tire. (thus the need for a spacer on larger tires) On 8" and larger wheels, the brake caliper rests bellow the tire, inside the rim diameter. (requiring no brake spacer) The axle setup shown on the Bearhawk LSA is set up for 6" MH wheels with smaller tires, or the 8" MH wheels with any size tires.

After the test flying period is over, and I am very familiar with the aircraft, a set of larger tires will be installed on another set of rims. (to allow for quick change over when needed). I will likely go with 26"/29" Airstreaks on another set of 6" rims, or possibly the 27.5" Dessers on 8" matco wheels.

3-21-16 (The drawing was removed due to incomplete information)

[stinger]

I have been reviewing the MH Matco wheel postings and find it interesting along with the drawing by LSA 140. Let me suggest you read pages 11&12 in the tech service bulletin REV G 02/2012 SRT as I do not see the correct diameter spacer necessary to engage the rubber seal thus preventing the bearing from rotating. Just my two cents worth. Stinger

[lsa140]

Do you have a link to that document on Matco's website? For some reason I can't find it. Which wheel and brake setup are you using on the axle photos above? Reading through their 2014 tech manual listed for the product I can only find that the proper grease and sufficient axle nut torque is required to keep the bearings from spinning.

[lsa140]

Here are the two External Caliper MH series wheel/brake setups that I am considering for the LSA:

6" - http://www.matcomfg.com/MHE6BESERIES...v-2336-30.html
Tubeless Kit - http://www.matcomfg.com/TUBELESSKIT-idv-3211-45.html

8" - http://www.matcomfg.com/MHE8BESERIES...dv-2331-4.html
Tubeless Kit - http://www.matcomfg.com/TUBELESSKIT8...v-3586-45.html

Second Caliper Kit - http://www.matcomfg.com/CONVERSIONKI...v-3637-48.html

Brake Rotor Spacer Kit - http://www.matcomfg.com/KITTWOWHEELA...v-3855-45.html

Master Cylinders - http://www.matcomfg.com/MASTERCYLINDER-idv-3404-5.html

[stinger]

lsa140: it looks like we have the same kit. There may be one difference mine are 18 months old . If you are using their axle, a bolt on set then all is good. They did not sell weld on axles at that time therefore I had to make up my own spacer set . I did find some info on line under their web site Tech support ( Tapered roller bearing preload) . Stinger