Question About Silicon Tires

[strangebrew]

Foam tires always lost traction on my track after a while (got dirty) Silicone worked pretty much always........
But as I said PGT glazed over & lost traction in a short time. I've completely scrubbed the track & have never put
a silcone tire on it since. The PGT's work better all the time....Even with crud or marbles on the track. I've put a bunch
of laps on some home-cast 25 shore Eurethane tires I make, I'm slowly "rubbering" up the track I guess. Honestly, I don't race on it too
much. I spend most of my time building with all the proxies lately.
I've tried coating foam with eurethane. It's messy & not easy to get a true coating on them. One of my cars in the P-Bop proxy has
eurethane coated foams. I'm interested in seeing the results on the different track surfaces......

[RichD]

How long a tire will go before it starts to loose traction depends on how clean the track is. Normally I test tires on a track that is as clean as I can make it. I normally run the car for three minutes and see what happens to the lap times, but sometimes I run even longer. I have tested silicone tires that could go an entire 12 minute race without being cleaned, I don't recall that being the case with any of the urethane tires that I have tested.
I have tested tires on a slightly dusty track, that is very difficult to do because the tires can pick up the dust or just push it to the side. I can tell you for sure that silicone tires will have better grip at first on a dusty track than urethane tires, but the grip drops off after just a few laps and the car will become undrivable. The urethane tires will not be as good at first but the grip will not fall off as much and the car should at least remain drivable, even if it is sliding a lot.
I would expect that urethane coated foam tires would work a little better than solid urethane tires. You can't just squeeze urethane goop out of a tube and coat a tire with it like you can with silicone. If I recall correctly a catalyst has to be added to get urethane to cure. Polyurethane finish is a different animal, if you coat a tire with that you will have almost no grip. I know of a guy that puts polyurethane on his front tires to minimize grip.
Back when I raced 1/24th cars the track had to be stripped down from time to time because the braid got covered with tire goop and rubber dust. After the track was stripped it had to be treated with spray glue, that is tire conditioner diluted with naphtha, or nobody would have much grip. From time to time I strip my HO track down with naphtha, it is a MaxTrax, which is made of Sintra. I have to run a car with gooped foam tires around to restore full grip.
As I mentioned earlier if I run urethane tires on a track right after silicone tires have been run on it a lot the urethane tires will get coated. If I strip the track down with naphtha and skip the gooped tires they still get coated. I have to do repeated cycles of running and washing the tires to get the track fully conditioned, after that little cleaning is needed.
I should point out that if you are doing formal races on a track you should get it fully conditioned before racing starts, otherwise the people that run in the first few heats will be at a disadvantage.

[HomeRacingWorld]

Some use drywall screen paper. Use a cheap single blade razor or diamond file to contour the inside edge. The razor works great here, seen many guys clean them up fast with this technique.

But if you choose the right tire for the wheel, little..if any is needed. Especially when mounting on aluminum wheels they are designed for.

[RichD]

In order to get the very best performance from any tire it should be glued to the wheel and trued using a machine. For a start not all wheels run true. Plastic wheels are always suspect and I was surprised to find that machined wheels sometimes have a fair amount of runout. In that case you will have a problem even if the tires themselves are true. If the tires are not glued to the wheels they will tend to separate from the wheels in the corners and the tires will distort so that the tread will no longer make full contact with the track. Several times I have had cars that were normally really stuck down start to loose grip. When I checked the tires I found that they had started to come unglued.
Even if the wheels and tires are perfectly true it is likely that any glue that is used will not be spread around evenly. Right after I glue tires I put an axle through the wheel and push down on that as I roll the tire on a hard flat surface. The more evenly you can spread the glue around the easier it will be to true the tire. As an experiment I glued and rolled a set of new tires. The wheels had been checked to be sure they were true and the tires that I use are made in CNC machined molds. I ran the car for a few dozen laps and examined the treads, it was obvious that the wear pattern was not even.
I have just completed an article on tuning cars for non-magnet racing and that has a section on truing tires. If you drop me a PM with your e-mail address I can send you a copy of the article.

[HomeRacingWorld]