They ran F-53’s
Kinda looks like a steer tire. Not saying that is a good or bad thing.
Thanks DD, I wonder how much slower they are than the F-53?
We tested the R750 and found it to be have good grip and was forgiving.
The test was over three weeks and at 70+ laps it was still as fast as a new set of F53 with 4 heat cycles. It is a bit slower than the F53 for the first 5 to 8 laps then it come in and stay good thru out the test test. we plan on using the test tire in the first race we run with the R750.
“Change is good”–Your Manager
Good for who (lol)?
No one likes change. I certainly don’t. But if the 750 is as good as the consistently positive reports, word will quickly get out and it will be hard to sit at home while others race-- for long.
If it is in fact comparable after 8 laps, they would probably be the thing to run (& tune for) asap.
[QUOTE=8modified;156060]We tested the R750 and found it to be have good grip and was forgiving.
The test was over three weeks and at 70+ laps it was still as fast as a new set of F53 with 4 heat cycles. It is a bit slower than the F53 for the first 5 to 8 laps then it come in and stay good thru out the test test. we plan on using the test tire in the first race we run with the R750.[/QUOTE]
Thanks for the details. sounds like a good all around tire that lasts.
[QUOTE=UREZ2PASS;156023]Here is the tire. It is a slick with grooves. The grooves are designed to promote grip and cool the tire.
The 650 was not a good compound. Hopefully the 750 works better. It’s been raced in many areas in the country with great success.[/QUOTE]
Slicks don’t have grooves, that’s why they’re called slicks.
Now about that " grooves are designed to promote grip " thing. Grooves mean less surface area on the tread face. How would having less surface area promote grip? Wouldn’t more surface area promote grip even better?
[QUOTE=Matt Albee;156076]Slicks don’t have grooves, that’s why they’re called slicks.
Now about that " grooves are designed to promote grip " thing. Grooves mean less surface area on the tread face. How would having less surface area promote grip? Wouldn’t more surface area promote grip even better?[/QUOTE]
It’s a slick with grooves. A street tire has tread, therefore it is not a slick.
I got my information from a tire engineer at Hoosier concerning the reasoning for the grooves. He’s smarter than both of us. He said the grooves help cool the tire and the edges of the grooves provide more traction.
EZ - laying the tire engineering smacketh down…
[QUOTE=UREZ2PASS;156077]It’s a slick with grooves. A street tire has tread, therefore it is not a slick.
I got my information from a tire engineer at Hoosier concerning the reasoning for the grooves. He’s smarter than both of us. He said the grooves help cool the tire and the edges of the grooves provide more traction.[/QUOTE]
Then what would you call a slick with no grooves? I’m sure the grooves offer better cooling though i hadn’t heard that the tires at NSS have been suffering from overheating. Edges of the grooves provide more traction??? Doesn’t make much sense, but if true, street tires with lots and lots of grooves should offer crazy traction on an OWM.
But now i’m curious why Hoosier, and all other race tire manufacturers, make slicks ( tires with no grooves ) at all if the grooved tires are better.
The groove tires stay cooler making them last longer. The leading edge of the groove promotes grip through the ability to flex. With a slick when you break loose you spin out or crash…period. Like mod8 said. These tires are more (forgiving).
So why do they grove dirt tires if slicks are faster .LOL
don62
Don,
I had the same question. In a previous thread it was determined that dirt tire “grooves” mostly run across the tire so that each of the sharp edges provides a little traction for the spinning tire.
As I understand it, these grooves (obviously) run around the tire and provide cooling and to some extent work in the corners in a similar fashion to the dirt tires except they provide lateral grip, instead of forward bite.
But, ya know, most of that is heresay and/or deduction on my part…
Nonetheless, there have been reports of positive results, so I am hoping for the best. I love them modifieds.
so the tire gets better as it get wore out ? I don’t believe it. and the groves helps cool the tire . my question is when at any time would a tire have time to cool down when your racing. answer never. and don’t say under caution because I bet any tire will cool down under caution . regardless slick, grove, street tire .
ST1:
I agree that conventional thinking/experience indicates that a tire gets hotter as it goes.
But for the sake of discussion, imagine the “heat sinks” you have seen on electronic equipment. A row of fins to dissipate heat into the atmosphere, an “air radiator” if you will. Same deal here wit da tars.
Now, they will get hotter just as you are thinking, but they may be a tick cooler than they would have been without the grooves.
Compound? Again hard to figure, but imagine a candy bar and now put some heat into it–it gets softer, right? Maybe the rubber molecules in the 750 respond to heat in that fashion.
Of course, I just made all that up, so take it with a grain of salt!
ps–Re: wore out. Eventually, of course, the things will reach a point of diminishing returns and stick less–that point just has not been found and/or posted as yet.
Of course, for years Dad has spoken of “Butyl” rubber tires that he had back around '62 that would “handle and stick as good as new right to the cords”.
Still though, if that point is beyond what the F-53s had, it may save the racer money.
Several years ago, Formula 1 required grooved tires, with the intention of decreasing grip to to slow them down. Anytime you decrease grip, you decrease temperature.
Jacko–Agreed–but then, that was their objective.
Their cornering speeds are absurd and I suspect the idea there was less grip due to less contact patch without having tires that looked like they came off a schwinn.
But that doesn’t mean that the design goals, execution and results here may entirely different.
Of course, at this point, it doesn’t mean they won’t be the same (ie slower), either (lol).
Wouldn’t a decrease in grip cause tire temps to go up? Seems like with the tires sliding instead of gripping, the temps would increase.
It would seem so, but that is not the case. Grip equals load, more load equals more heat
Lol
Here we go again. So know anyone who runs a mod at showtime,citrus,aberndale or Desoto has to buy tires to come race at New Symrna. LOL and they want car counts ? Brilliant. simply brilliant. So 4 tires over there are what ? $525 dollars ? What do they pay the winner for a regular show ? Anyone ?