Air Wheels and Silicone tires

[jaws]

I have been asking myself if the NSR Air wheels will work with silicone tires. On the NSR Corvette the rear wheels are wider than the fronts, so you can not just swap them. The rear tires will "sink" in the center with silicone tires. Does this sinking of the tread really hurt the performance of the car? I run on mostly Carrera tracks, some painted and some not. I also have Thunderslot cars and they have the air wheels also. I am using Quick Slicks on this car, Thunderslot. What is the purpose of these wheels vs raised rib wheels, like Slot.it wheels?

Jim W

[HomeRacingWorld]

Well you will get plenty of feedback, mostly opposite of mine.

They do not amount to anything IMHO. I have stock Thunderslot/NSR and ones with the new Quick Slicks. The QS equipped models are just a faster car overall.

The NSR/TS rubber is great when sanded, but I have already seen where they are drying out and losing the grip properties they once had.

The "sinking" does reduce traction on my smaller home/wood track. I see zero benefit. Now, others with larger club tracks say they prefer them.

Like most cases, just test for the tracks you race on and choose the best weapon for combat :)

[WB2]

At one time Dennis Sampson offered a foam filler for air wheels.

[Audi1]

This is a topic that comes around frequently and is difficult to really nail down, since many people have different takes on it.

With air system wheels, all tires made for solid hubs will "sink" a little in the center when mounted. It's my understanding that when the air system wheels first came out and were raced, the racers used to try to make the seal between the wheel and the tire air-tight and then injected air or an inert gas into the space between the hub and the tires, giving the tire some of the properties of a pneumatic 1:1 tire. But, coming to races with hypodermic needles in your car box was not the image that the hobby needed, so except in a few cases, it's pretty much disappeared now. If some on this board are still injecting air/inert gas into air system wheels/tires, then there are probably a lot of board members would be interested in hearing about your results with that approach.

In the absence of that, what you now have is a situation where at speed the centrifugal force on the tire pushes the center material outwards and at rest the center material compresses inward. There are those who consider that this outward push at speed, such as on straights, deceases the contact patch size and, therefore, decreases drag, which can translate to additional speed. When the car decelerates, such as when entering a turn, the center flattens, which provides more grip, which is usually a good thing in corners.

Many racers true (sand/grind) their tires flat with the air system wheels. This does two things: 1. it thins out the center of the contact patch, which facilitates this inward/outward flex, and 2. if gives the racer some psychological comfort, since he's now starting with a flat contact patch.

The Quick Slicks for TS air system wheels have the air system space filled up with silicone. I use this tire on my club racing Lola T70 and it works very well for me.

In my experience, for whatever the reason, the air system wheels do work and there are foam rubber insets available if you want to use them.

Allan

[RichD]

If you put a tire that is designed for a regular wheel with a center ridge on a NSR "air" wheel the center of the tire might be cupped. That would be more likely to be an issue if the tire had a very low profile. I have one NSR car with the original "air" hubs and that has silicone tires with a taller profile. A close examination of the tire treads indicate that they are very slightly cupped. The tires have not been glued and trued. If I wanted to true the tires I would have to glue them. In any case the car is a good runner, but not quite good enough to actually race it. One of these days I will have to slap on a set of glued and trued tires and wheels.
In any case why not do some testing?

[Slot GT]

I just swap the front wheels for the backs on the NSR cars. Easy peasy. No messing around with air hubs or fillers.

[Rleog]

“......at speed the centrifugal force on the tire pushes the center material outwards and at rest the center material compresses inward. There are those who consider that this outward push at speed, such as on straights, deceases the contact patch size and, therefore, decreases drag, which can translate to additional speed.”

The rear wheels are obviously the powered wheels. As such there is little “drag,” as there would be on the front wheels. Any additional speed gain might be due to the increased diameter of the rear tires due to the outward push of the center section of the tire. I imagine that you would have to have a very long track straight to have this effect translate to any lap time advantage.