sheeley

exceed sells a rim with japanese rubber, american rubber, or italian rubber all at very different costs. same rim
I think the question that started this post was referring to that.
I am personaly going to test all 3 to see if there is a difference in grip. Seems to be only way to find out If I noticed no difference I'm sticking with american rubber since its cheapest.(exceed)

MugenDrew

iTrader: (36)

Sorry for quoting the whole post but...!KICK AZZ!

Jack Rimer

Actually, Xceed sells Japanese, American, and European made tires all using JAPANESE rubber. The price differences are simply a matter of how much profit each manufacturer is comfortable with making. We have to compete in a market that is extremely price driven here in the US. I'm not sure about Europe and Japan, but price dictates the market over brand loyalty here.

sheeley

good to know, thanks

fulcrum2

This time we got some intersting facts from Jack - please see my comments :

Variations from batch to batch (cell structure) Tire manufacturer has no influence
Season the rubber was manufactured Tire manufacturer has no influence
Rim stiffness
Rim material and how it reacts to heat and cold There can be an difference- but also variation from batch to batch (plastic)
ID of the donut (stretch) Tire manufacturer has no influence
Amount of heat generated by the truing process User influence (as low as possible)
Age of rubber Tire manufacturer has no influence
Flexibility of the contact adhesive joining the rings Could make a difference
How a company marks a tire (durometer)- This is the biggest difference Agree!
Heat generated during cutting of the donut Could vary as well...
Not to mention about 10,000 car or track variables that could impact how a "tire" performs from run to run For sure!



Final verdict: Buy the cheapest ones and hope for the best...

Team drivers get selected tyres, so their results can not be included in the equation

DS Motorsport

iTrader: (2)

I still find it hard to believe that all the tires are the same, since the handling differences are huge.

I tried all the types of xceed tires and the Japanese ones clearly handled a lot better then the other types. Also the jap version gets really hot and sticky while using it, never experienced that with other tires.

While the xceed tires worked great for my 720 they were terrible on my Xray NT1.
The NT1 runs best on GRP tires, on the xceed tires the car reacted terribly slow.
I think i tested about 5-8 different tire types and brands when i first got the NT1, and with the GRP tires i was about .2-.3 seconds a lap quicker.
So there must be a difference.

BTW all tires where tested on the same day, and all where fresh, they all had that very distinctive smell that fresh tires have.

I think the piece posted by TomB is the closest to reality.

TomB

iTrader: (10)

things my have changed now, but about 3 years ago i remember there was a distinct difference between Kawaharras, Ennettis and GRP's. I say three years ago, because i haven't used grp's since then. I've only ever used GQ and Kawaharra's for the last few years.

Obviously Jack being the tyre guy knows more, so if he says they are all the same i guess they are. Maybe the difference i notice in the foam is the cell structure he mentions

overall though, different brands perform differently, even if they all use the same foam as Jack says. I noticed a distinct difference between GQ's and Kawaharras at my home track, again it's down to the rim in my opinion, but also i think there is a difference in how the shore rating is measured, as the GQ's 40 shore foam (rim not included) are definately harder than a kawahara 40 shore.

Jack Rimer

Did you check the durometer? The company that makes the tires for Kawahara and Kyosho skews their numbers soft. So you are always going to get more "grip" from these when compared to a similarly rated other brand.

Here is a true story: About 5 years ago I called a shop on the west coast to ask them why they didn't stock our tires. The owner told me that "JACO's don't work on our track. The rubber is the cheap American style, not the Japanese stuff used by other brands". I asked him which brand he used that worked the best. When he told me I had to laugh. It was a brand that we made for this company using the exact same rubber we use on our tires (just a different rim). But to him, it was day and night. Obviously, he was completely off base and wrong, but he swore by it. I never told him otherwise since it didn't matter to me....I was selling the tires indirectly to him. Since then, I have the utmost skepticism for anyone who claims ANY tire is head and shoulders above another....including ours. I don't doubt that you can go out and run faster with one brand over another, but I'm not convinced these differences are due to any manufacturer having better rubber than another.

J.Gonzalez

iTrader: (16)

Thanks Jack!

Any particular durometer device you recommend?

What about storage of tires any recommendations?

How would you describe how rim stiffness affects handling?

Cheers
Jamie

J.Gonzalez

iTrader: (16)

Real question should be what in the world are the yokomo guys using for rear tires on 1/12! Now that is mystery rubber

Those guys have everyone covered every worlds!

Jack Rimer

I have used a Paris durometer for many years (not sure if it is still available), but the technical name for the numbering system we use is a Shore Type C Asker scale. This is more prevalent in Europe and Asia. Over here they mostly use a Shore 00 for measuring closed cell foam. I find it worthless. A MaxMod is fine when comparing tires to each other, but don't use it to check if your tires are what the package says. It usually reads quite high. Again, it is fine for using as a reference...as long as the reference is the same Maxmod.
I have not played with tire storage too much. I know many people seal the tires in a bag between uses and that is fine. My experience has shown that as long as the tire has been kept out of ultraviolet light, it will not crack. We have literally run tires that were 4 years old and won a ROAR nats with them (long story, but true). I don't recommend that, though. On gas tires we do not keep huge inventories of finished tires because we want to assure freshness. All tires "age" when the skin is removed from the sheets and the gas escapes the cells. We try to minimize this by making most gas tires to order. Even in a bag, the tires harden and age.
Rim stiffness and handling is like opening Pandora's box. There are so many conditions and circumstances that impact how a wheel performs. We try to balance stiffness with durability. Most racers will say they want the stiffest and lightest wheel they can run....until they start breaking them. Then they bitch at us for making brittle wheels! Really stiff wheels work well on high bite or high speed tracks, but many local tracks are neither large nor high traction. We try to have a wheel that is stiff enough to work in most conditions, yet not so stiff that it breaks. Our drivers like a little flex in the wheel, but also have the option to cut or grind the ribs if they need more flex. Through the years we have experimented with both extremely stiff and extremely flexible wheels and found that somewhere in the middle is the best.
My answer to the Yokomo tire question comes from Masami himself. Many years ago when we were still with Pro-Line, we sold donuts to Yokomo in bulk. Evidently, one particular batch we sent was unusually tight in cell structure. These worked EXTREMELY well in 1/12 asphalt racing. They had a limited number of donuts and evidently these are now running out. I guess I should have saved some for me.

avs

iTrader: (2)

thank you for the insight, but it prompted 2 questions.
1) about 10years ago, in 1/8 foam in my area was limited to Ellegi and Paris. the Paris product seemed much denser, longer wearing compared to Ellegi for the same grip. was i hallucinating or was there a real difference in the rubber? the wheels were the same because i was mounting donuts myself.

2)todays 1/12 scales tires (by the way, thanks for using a shore rating in the part number! the color code is crazy) what is the difference between pink and yellow rears, is that 2 grades of japanese rubber? yellow being a lower density foam than the pink?

thanks again for the background on this.

wingracer

iTrader: (24)

I don't think the yellows are jap rubber. Remember, carpet tires come in all varieties.

Jack Rimer

Yellow is Japanese rubber. It is just more "foamy" and less "rubbery", much like the American foam. Yellow is like a Japanese Green. Pink has more natural rubber and is a completely different type of foam....denser, stickier, more durable. Yellow reacts well with traction compound, thus making it a good 1/12 tire.
If you were using Paris donuts, there is a good chance they were made by us. We used to supply Ron with donuts for years. My guess is that the donuts that wore better were simply firmer.

wingracer

iTrader: (24)

Interesting, I felt like the yellows acted a lot like the old american greens so I figured they were american rubber. I didn't know the japanese were making that style of rubber.

I still prefer magentas on my track though.