have R7's changed? disturbing grooving
#1
Instructor
Thread Starter
have R7's changed? disturbing grooving
I’ve been seeing some strange patterning on the R7’s treads that I’ve purchased this year (build dates late '17 and early '18) and I was wondering if anyone else has seen it. I will show you in the pictures below, but on the first heat cycle, I get grooving on the outside of the tire and cracking on the inside. It almost looks like the tread is not properly adhered to the carcass. By the third heat cycle, the grooving on the outside wears down fairly flat, but is still visible till that edge is worn out. Then when I flip the tires on the rim, the crack that formed in the first heat cycle, wears into a groove and then progresses the same way the other edge did till the tire is worn out. It looks like interference with the fender, but it’s not. It appears on first heat cycle and happens on all four tires, inner and outer edges. It happens to the 295 and 315’s I run on the front and the 335’s I run on the back. Did Hoosier change something about their manufacturing process starting mid ’17? It’s a bit unnerving so I’m reaching out for some feedback.
here is what the cracking on the inside of the tire looks like (some picts reflect the tire on the outside only because I'd already run the outer edge through it's life and had just flipped the tire. so that edge has not seen cornering wear yet.)
lastly check out this tear that occurred towards the end of the tire's life. at first I thought this happened during braking, but that part of the tire is not on the ground during braking. then I noticed the tear has material on the inside suggesting it tore from outside to inside during cornering. I've never seen that on my tires before. also, if you look inside the tear, there is a rather smooth surface below the tread. in the past when I've worn a tire past the tread, I'd see the fabric belts, but the tread would be firmly adhered to the belts. here it does not look to be adhered. Kind of making me want to switch to Pirellis for a while till Hoosier shakes this out.
lastly, here's what these tires have looked like at the end of their life. The grooves make their way all the way down. odd
here is what the cracking on the inside of the tire looks like (some picts reflect the tire on the outside only because I'd already run the outer edge through it's life and had just flipped the tire. so that edge has not seen cornering wear yet.)
lastly check out this tear that occurred towards the end of the tire's life. at first I thought this happened during braking, but that part of the tire is not on the ground during braking. then I noticed the tear has material on the inside suggesting it tore from outside to inside during cornering. I've never seen that on my tires before. also, if you look inside the tear, there is a rather smooth surface below the tread. in the past when I've worn a tire past the tread, I'd see the fabric belts, but the tread would be firmly adhered to the belts. here it does not look to be adhered. Kind of making me want to switch to Pirellis for a while till Hoosier shakes this out.
lastly, here's what these tires have looked like at the end of their life. The grooves make their way all the way down. odd
#2
I think that is called a cold tear. It occurs when you go out too hard on the tire before you build heat into it. That's why you see it on the inner or outer 1/3rd of the tire most of the time. You can make that worst with camber setting or going out hard on low starting pressure or a really busy track with less long straights and lots of turns. 8th pic down looks like a popped blister too. Again that is from overheating/overworking a tire. Graining is also related to this. Its the step before cold tear or blister.
#3
Instructor
Thread Starter
I think that is called a cold tear. It occurs when you go out too hard on the tire before you build heat into it. That's why you see it on the inner or outer 1/3rd of the tire most of the time. You can make that worst with camber setting or going out hard on low starting pressure or a really busy track with less long straights and lots of turns. 8th pic down looks like a popped blister too. Again that is from overheating/overworking a tire. Graining is also related to this. Its the step before cold tear or blister.
#4
Rennlist Member
Have seen the same in a few recent sets. Cold starts at 26-27 psi followed by immediately leaning on the tire. Worse at abrasive tracks (NJMP). Will be interested to hear what Hoosier says.
#5
One thing they won't say is it is their fault! For all we know there is a defect. We have seen hoosier defects before. Hoosier makes the fasted dot-r tire but the worst quality control.
Trending Topics
#8
Rennlist Member
cant you see the rubber on the blue fender on the pic above. could the fender be touching the tire? it looks suspicious there. I'm running the same sizes you are, but are not seeing this issue. i also see MUCH more tire wear going to the outer rubber mold casing line. its almost like you are running too much pressure.............oh you are. starting out at 30psi is where i end up with pressure btw.
I also see some of that rippling wear sometimes. weird
I also see some of that rippling wear sometimes. weird
#9
Thundermoose few years ago had same problem that developed last 10 minutes at the end of my Enduro at Mid-Ohio heard clicking sound as wire rubbed on suspension. Received replacement tire from Bob Woodman after they spoke with Hoosier.
Steve
Steve
#10
Originally Posted by serickson
Thundermoose few years ago had same problem that developed last 10 minutes at the end of my Enduro at Mid-Ohio heard clicking sound as wire rubbed on suspension. Received replacement tire from Bob Woodman after they spoke with Hoosier.
Steve
Steve
#11
Nordschleife Master
Ah the old wire of death. Seen it on R7s and slicks many many times. One time at Daytona it took out the rear of a 996tt including the intercooler, bumper, and took paint off most of the rear fender. After much hassle and "we have never seen this before" they graciously gave us a new tire. Funny after the third or fourth claim with Hoosier with the same person saying they never saw it before I reminded them that he was the same guy I spoke to the last few times. Then quick deny deny deny but will replace this time.
#12
#13
I've had a similar wear pattern on my R7s. Rechecked camber (front -3.0 and rear -2.0) and toe (front=0 & rear=0) which is my standard setup for the last couple years. I have been starting with slight lower tire pressures, and I figured it was that combined with pushing to hard before they came up to temp and pressures.
#15
Rennlist Member
It was scary running Hoosiers at Daytona for the Runoffs. Those tires are not for super speedways. My math showed we overload the tires. Hoosier was silent on this. Somehow before Runoffs Hoosier told us to add about 4psi to recommended Hoosier hot pressure 42psi so 46psi! Yeah right...nobody did that! I think SCCA knew what was going to happen and mysteriously we were given 2 warm-up laps before the race started. We all survived...