Has anyone run into compatibility problems with the 26" Goodyear tires and clearance from the brake calipers? My wheels and brakes are the Cleveland 40-75b, which includes the 164-01501 brake disc. A deeper brake disc would provide more clearance, as would some sort of spacer between the brake disk and wheel.

Some installations of these tires do require a spacer.

MTV

I got a chunk of 4130 tube and cut a spacer out of it for mine to clear.

jaredyates wrote:Has anyone run into compatibility problems with the 26" Goodyear tires and clearance from the brake calipers? My wheels and brakes are the Cleveland 40-75b, which includes the 164-01501 brake disc. A deeper brake disc would provide more clearance, as would some sort of spacer between the brake disk and wheel.

My AK Bushwheels 199-62 kit, all installed, with the temporary Desser 8.50s I have on, gives me the following clearances:

Inside face of disc to wheel: 1.05"
Smallest clearance of tire to caliper: 7/16"

You might be able to order new deeper discs. I'm not sure if it's practice to add shims between the disc and wheel, as it seems like it could introduce the possibility of movement as the fastener gets longer.

jaredyates wrote:Has anyone run into compatibility problems with the 26" Goodyear tires and clearance from the brake calipers? My wheels and brakes are the Cleveland 40-75b, which includes the 164-01501 brake disc. A deeper brake disc would provide more clearance, as would some sort of spacer between the brake disk and wheel.

Most people shim the disc out from the wheel if they have interference issues.
A full round spacer with 3 holes (or 6,as req'd) is supposed to be better than using washers.
A different tork plate might do the trick too. Does anyone have an STC for a certificated airplane which identifies the correct Cleveland kit number or wheel / disc / tork plate p/n's for use with the 26" GY?

I don't know what Wup is up to but I know he knows the right way to solve this problem. Might check with him at backcountry connection.com

Even with the correct setup there is no way around rubbing between the brakes and tires. This problem is exasperated at low tire pressures. The only way to fix it is the alluminum disc spacer in most cases.
Airframes should sell the disc spacers, stoddards airparts has them. The Cessna caravan even uses an brake disc spacer approved with an STC when running 29 tires.

I drew up a quick drawing for those of you who might be like me and need a visual aid. The Cleveland drawings of course exist and are great but this is a simplification for this problem. I wish someone had drawn this for me years ago.

{removed}

The full circle disc spacer is best, or the cleveland part, which is an elongated curved washer also works.
It is important to mount the torque plate so the caliper is forward of the axle, not behind the axle. This precludes the tyre grabbing the caliper if tyre is side loaded inward, or tyre goes flat. It also provides better braking as the rotating tyre is pulled into ground not away, when braking.

Thanks everyone, the blue lines in the image show the problem exactly. If I put spacers between the brake disc and the wheel half, is there any concern about that changing the alignment of the disc relative to the caliper? The spacial orientation is confusing, but I gather it would cause the caliper to float further out on the pins?

Even with the correct setup there is no way around rubbing between the brakes and tires. This problem is exasperated at low tire pressures. The only way to fix it is the alluminum disc spacer in most cases.
Airframes should sell the disc spacers, stoddards airparts has them. The Cessna caravan even uses an brake disc spacer approved with an STC when running 29 tires.

No idea why, but my GY26's mounted up without rubbing and without spacers. Running double-puck cleveland brakes on a 170, with tire pressures down as low as 8psi. Just lucky I guess

I'm putting together a set of wheels and rotors for a spare and using the 164-01501 rotors like you. I measured them against my ABI 199-62 kit that I have on the wagon, clearly seen in the pics below. The ABI setup has more clearance between the rotor and wheel than the cleveland setup. I'm not sure what the part number is for the ABI rotor, but buying a couple of those will get you another 1/4" of clearance. As long as you have enough room where the pins go through the torque plate you should be good.

Before I put the ABI kit on the wagon, I had the cleveland wheels with 164-01501 rotors, and there was only about 1/16" clearance between the calipers and the tire, with no evidence of rubbing. It's tight, but things don't really move around much during operation, and I doubt the Goodyear tires will roll over too much even at a lower pressure. YMMV

Cleveland wheel with 164-01501 rotor. About 2-1/4"


Same as above, rotor to wheel clearance at a touch more than 5/8ths"


ABI 199-62 kit shows 2-1/2"


ABI rotor to wheel spacing close to 15/16ths"

jaredyates wrote:Thanks everyone, the blue lines in the image show the problem exactly. If I put spacers between the brake disc and the wheel half, is there any concern about that changing the alignment of the disc relative to the caliper? The spacial orientation is confusing, but I gather it would cause the caliper to float further out on the pins?

All you're doing is moving the wheel and tire away from the brake and disc business by adding that shim between disc and wheel hub. The bigger problem I see is running out of axle length. I have minimal threads exposed on my axles with my current setup and that clearance I stated earlier.

I talked about this one time with RobW56, since he bought my 170 and put bushwheels on it. I'd always felt there wasn't enough clearance from caliper to tire and worried about opening the tire like a can opener. He brought up the good point that the tire sidewall that close to the center is pretty stiff and doesn't bulge out as much as it does near the axial beam of the tire. Is that a term?

Very helpful info, thanks! Is there a consensus about how much clearance one should have there? My calipers are front mounted.

Zzz wrote:All you're doing is moving the wheel and tire away from the brake and disc business by adding that shim between disc and wheel hub. The bigger problem I see is running out of axle length. I have minimal threads exposed on my axles with my current setup and that clearance I stated earlier.

Are you sure about this Zzz?? An axle spacer would move the entire wheel/rotor assembly further out, not changing the clearance between the rotor and wheel. A 1/8" spacer between where the rotor mounts to the inside half of the wheel would provide a 1/8" more clearance between the caliper and the tire, which is what I think is the goal here. The only problem is that you need to make sure your caliper pins are still all the way inside the torque plate when you add the spacer. (this is where the diagram above is wrong, it shows the caliper hard mounted to the torque plate which isn't the case.) If you use a 1/8" spacer, you should stick your finger inside the wheel and make sure you have at least 1/8" of pin sticking out of the torque plate. This excess will go away when you add the spacer.

The way I see it you have two options to change the spacing between your caliper and tire:
1- a spacer between the rotor and wheel, which would necessitate longer wheel bolts.
2- a different part number brake rotor with a deeper spacing. (more $$$)

jaredyates wrote:...The spacial orientation is confusing, but I gather it would cause the caliper to float further out on the pins?

I believe you are right here. That's what I meant by sticking your finger inside to check that you still have some room left on these pins before you add a spacer.

Another point here. Are your brake pads brand new?? If they are, than they are still pretty thick which pushes the caliper closer to the tire, but as they wear out, your clearance between the caliper and tire will increase.

bart wrote:

Zzz wrote:All you're doing is moving the wheel and tire away from the brake and disc business by adding that shim between disc and wheel hub. The bigger problem I see is running out of axle length. I have minimal threads exposed on my axles with my current setup and that clearance I stated earlier.

Are you sure about this Zzz?? An axle spacer would move the entire wheel/rotor assembly further out, not changing the clearance between the rotor and wheel. A 1/8" spacer between where the rotor mounts to the inside half of the wheel would provide a 1/8" more clearance between the caliper and the tire, which is what I think is the goal here. The only problem is that you need to make sure your caliper pins are still all the way inside the torque plate when you add the spacer. (this is where the diagram above is wrong, it shows the caliper hard mounted to the torque plate which isn't the case.) If you use a 1/8" spacer, you should stick your finger inside the wheel and make sure you have at least 1/8" of pin sticking out of the torque plate. This excess will go away when you add the spacer.

The way I see it you have two options to change the spacing between your caliper and tire:
1- a spacer between the rotor and wheel, which would necessitate longer wheel bolts.
2- a different part number brake rotor with a deeper spacing. (more $$$)

I'm not totally sure of anything anymore, but you're right. I removed my diagram since the caliper was an inaccurate representation (I drew it from memory...obviously a little selective and grossly disproportionate) and I don't want that to distract. It's not hard mounted, the pins pass through the torque plate freely, and the caliper free floats along those, following the disc rotor, so there is some lateral play but it's not much, especially with fresh thick pads.

Either way, the tire and wheel have to move outboard without moving the position of the rotor. That requires, like you said, a deeper disc, or shims, and more axle spacer to take up the new gap.

The relationship of the caliper to the disc rotor has very little flexibility, even though the caliper floats on those pins. It relies on the offset of the torque plate too. It's a weird little relationship that is very difficult to explain with words, and one I didn't fully understand until I fondled it a lot.

I'll update my shitty drawing with a better caliper if anyone finds it helpful. Here's a pic of my current setup:





Kinda hard to see the depth of the disc and wheel and the axle spacer length in a photo without it torn apart. Disregard the non-locking nut on the flange bolts. They are temporary. I know how people love to point that stuff out.

The problem is that the 40-75b wheel assembly which uses disc number 164-01501 is designed and intended to be used with 600x6 tires and has less offset (distance) from the brake disc to the wheel. The 40-75d wheel assembly which uses disc number 164-03601 is designed and intended to be used with 800x6 tires and has the greater clearance that you require. The use of the 40-75d also requires the use of longer guide pins in the brake caliper and longer bushings in the torque plate to insure adequate engagement of the guide pins with the bushings. This would also be required if you used a spacer to increase the offset of the disc from the wheel. Just as a note the 199-60 kit is for 600x6 tires and the 199-62 kit is for 800x6 tires for the same model aircraft. Hope this helps.

Tim

bat443 wrote: Just as a note the 199-60 kit is for 600x6 tires and the 199-62 kit is for 800x6 tires for the same model aircraft. Hope this helps.

Tim

Thanks Tim, it does help. I didn't shop for this wheel set when it was new, but even if I had, I probably wouldn't have known that. I called Airframes AK to ask about their spacer kit, and it sounds like theirs is pretty fancy. It comes with two 1/8" rings for each wheel (allowing 1/8 or 1/4 spacing), plus the longer bolts and hardware. It's not cheap at $177, but then I guess the best seldom is.

Since I don't have much to lose by trying, I'll go out tomorrow and use washers to get as much clearance as possible with the old bolts. The current thread engagement will probably allow for close to 1/8". If I replace the standard washer under the nut with a thin washer that will buy me an extra 1/32" too. That should help me gauge tire clearance and pin engagement. If the pins allow and I still need more space, then I'll order some longer bolts and make a thicker spacer ring.

I have about 160 hours on the current pads and discs, and they have worn a little, but not very much.

Unless I missed something, sounds like you are using the wrong torque plate. Did you change it when you changed everything else. The correct one is P/N 075-0501
Gary