SlamMan

I have a few newbie questions about tires.

When do you use foam or rubber? Is that determined by the local track and race class?

How long do tires last?

Are premounted the way to go for both rubber and foam?

XrayFK

iTrader: (1)

In almost all cases, foam for carpet and rubber for asphalt.
Tire life depends on a LOT of things, such as:
softness of tires (softer wears faster)
track temp
motor (mod obviously wears much faster than stock)
car setup (camber mostly)
crashing (for foams)

Generally, foams will last longer because unlike rubber, it doesn't matter which part of the foam it is, the traction is the same. So you re-true the tire every other run or so, and you still have the same material. Whereas rubber tires, once that "layer" of traction is gone, the tire is done.

khyron

I'll pile some of my own on here, because I've been wondering...

What's the deal with "pink" and "orange" versus "shore" numbers with foams?

What's "two stage" mean with foams?

Why are some sedan foams described as "for nitro" when electric and nitro touring cars seem to have exactly the same wheels?

Grizzbob

iTrader: (2)

Well, I don't have an answer for all those questions, but I may be able to enlighten you on a couple of them. I think they decided here to use a color system instead of pure numbers because it makes it easier to include tires in a batch that are not EXACTLY at a given shore rating but are close to it(so if you have some purples, which are typically around 40 shore rating, you'll actually see them in a range of shores from say, 38-42 or so). plus, I think it can make it a bit easier to remember for some people what tires they need(pink & purple can be pretty easy to remember, rather than recall a given set of shore ratings, but everyone's different). Now about 2-Stage foams, I believe those are actually 2 different kinds of foam in the tire, the outer layers are what we normally use, & underneath is a denser layer that adds more support to the outer layer(I think it's kinda like having a firmer insert in a rubber tire). And about nitro vs. electric foam tires, for the most part the wheels are the same(or very close), but the difference might be in the foam itself(but I can't be sure on this, as I have no direct nitro experience). Also, on the subject of what tire for what surface, in the US, we also see a fair amount of rubber tires on carpet, & in those cases the tires can last MUCH longer than any foam tire(especially if they're something like TakOff's premount CS-27's, those things can last FOREVER on carpet, the wheels will break first before the tires lose any significant grip). but the best thing to do when figuring out what tires you want or need is to check out the track you'll be racing on & get an idea of what works there & what the locals are using(so you don't end up being all alone with something, like being the only guy at a carpet track with rubber tires & everyone else uses foam, BIG mismatch there).....

khyron

Much appreciated, and I hope that helps the original poster out as well!

I think what's confused me the most is that while yes, a color system is much simpler to remember, I've never seen a chart anywhere that lists the colors with their firmness (or equivalent shore ranges, which would be awesome) and the names used for the colors seem silly. Why have something called "double pink" when you could just have used another color? The fact that "double" means something different than "two stage" seems non-intuitive.

However I'm not going to argue into the wind about something I can't change, I just want to learn more so I'm not so confused by it.

XrayFK

iTrader: (1)

Actually the 2-stage foams have a lighter core material, so the tire has less rotating mass and in theory can accelerate faster. Also, the base foam has a different compression characteriestic so the tire creates more traction with a larger contact patch area.

Grizzbob

iTrader: (2)

Actually, Trinity maintains a color/shore number chart on their site, which I have saved on my system. In fact, I think the file's small enough I can attach it here, so let's try it...

Oasis

iTrader: (38)

Premounts are the way to go on foams (Back in the Day a few of us pan car guys would spend a day mounting tires on rims and truing them up..that was before TC's.. ) I might be old and forget stuff but I will always remember gluing foams..yuck. On how long tires last..They last until the traction is gone (smart ass answer.. ) It depends on the surface, The track Temperature, Their are a lot of factors on the how long. Club racing I tend to use my tires for a lot longer than I would for a Big race. Given you are using the "right" tire for the track a set of Take Off CS-27's should last you for 3 or 4 races, That is with good traction and running stock, Mod you can cut it in half. Most of the Tire manufactures are starting to sell pre-mounts, I think you can now buy Sorex's with speedmind rims. One of the pluses on gluing up your own rubber tires is you have a choice on your inserts (Yes they can make a huge difference in performance) One of the better articles I have read on rubber tires and inserts was written by RCTECH owner Shane Archer for XRC. If you have questions it has the answers..

cvt01

iTrader: (2)

Is it available online?