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Discussion Starter · #1 ·
Hey All,

Here in CO, we have a production/spec racing class that requires we run DOT tires. The de-facto choice in the past was a 110/140 Pirelli SC. Anyone played with other dot race tires or sizes? There doesn't seem to be many alternatives except *maybe* Michelin's Power RS. Some of our guys run a 120/150 setup but it's less popular than the factory size.

Fellow racer feedback would be appreciated!
 

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I've heard great things about the new power RS tires. They come in stock sizes as well. No personal experience on them though.
 

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Alpha 13's are good but you need the 150 rear if you go this option. RS10's are garbage. Supercorsas are still king. Haven't tried the Michelin power rs. I prefer front Dunlop alpha 13 110/70 & rear supercorsa sc2 140/70

Tried the 150 rear supercorsa and it was notably heavier and my bike handling was negatively affected (I didn't make suspension changes like I should have). I found the 120 front to taper-off and not give me enough feedback when it runs out of grip compared to the 110 which gives clear feedback at the edge of the tire
 

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Discussion Starter · #4 ·
Alpha 13's are good but you need the 150 rear if you go this option. RS10's are garbage. Supercorsas are still king. Haven't tried the Michelin power rs. I prefer front Dunlop alpha 13 110/70 & rear supercorsa sc2 140/70

Tried the 150 rear supercorsa and it was notably heavier and my bike handling was negatively affected (I didn't make suspension changes like I should have). I found the 120 front to taper-off and not give me enough feedback when it runs out of grip compared to the 110 which gives clear feedback at the edge of the tire
Thanks for the feedback. Never thought of running different brands front/rear. I ran the SC setup in 120/150 size for a few rounds and I agree. Turn in is markedly slower and since the tire profile is all fubar it's tough to tell how much lean is left.
 

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I know some of the fast guys in TX are running the Power RS on the rear in 150; I think they're running the Power Cup Evo up front. I was having a casual conversation with the owner of a race shop here so I didn't think to ask which front when he said they were running a "race tire" up front.

Jesse @jbluetooth has done some testing with the Pirellis before deciding to go to slicks, but he's posted some of his thoughts in this post: http://www.r3-forums.com/forum/538-tires/124129-more-tire-testing-done-i-ve-changed-my-mind.html and also in a more recent race report: http://www.yamahar3racing.com/2017/...nd-5-chuckwalla-valley-raceway-ccw-yamaha-r3/

I'm going to be running Pirelli Supercorsa in 120/150, but I'm just a trackday rider and not quite at race pace so my feedback won't be worth much to you.
 

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I'm a pirelli fan, so I'm sticking to the Supercorsas, but I think next set I'll get I'll be switching to the 110 front to try it out. Right now i'm running 120/150 as well.
 

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Discussion Starter · #7 ·
I know some of the fast guys in TX are running the Power RS on the rear in 150; I think they're running the Power Cup Evo up front. I was having a casual conversation with the owner of a race shop here so I didn't think to ask which front when he said they were running a "race tire" up front.

Jesse @jbluetooth has done some testing with the Pirellis before deciding to go to slicks, but he's posted some of his thoughts in this post: http://www.r3-forums.com/forum/538-tires/124129-more-tire-testing-done-i-ve-changed-my-mind.html and also in a more recent race report: http://www.yamahar3racing.com/2017/...nd-5-chuckwalla-valley-raceway-ccw-yamaha-r3/

I'm going to be running Pirelli Supercorsa in 120/150, but I'm just a trackday rider and not quite at race pace so my feedback won't be worth much to you.
Thanks for the link! Good thoughts on tire size... Might give me some wiggle room on other brands to experiment with.
 

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I was talking to Ken hill today at motoamerica.

If you have your front and rear suspension upgraded then the SC1, SC2 work awesome because of the carcass flex.

If you don't he recommended the Dunlop Alpha 13s.

I didnt ask about the power Rs.
 

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Dredging up a thread from the dead.

First year on the R3 race bike that I built last winter although I have been racing at a regional level for a long time on a different bike. Ohlins cartridges in stock forks, Ohlins shock.

Production class requires DOT tires.

The tracks that we race on are typically tight, frost-heaved, and rather neglected ... It's perhaps telling that my braking and turn-in points are defined by the lines of grass growing up through the cracks in the pavement. "turn in at the last line of grass before corner 11"

Initially I built the bike with the Dunlop Q3+ tires that are the "spec" tires for the Canadian national CSBK series, 110/70-17 front 150/60-17 rear. Recommended tire pressures from Dunlop were 30 front 24 rear cold and I only tweaked that to 28 front 24 rear cold. I really had no complaints about these. Slides were predictable and generally from the rear, which I can deal with.

But, at the last round, these tires were finished after Saturday, and the Dunlop distributor at the track was out of the required sizes, so I crossed the paddock to the Michelin-Pirelli-Bridgestone distributor, and put on Michelin Power Cup Evo in the same sizes, 110/70-17 front, 150/60-17 rear. Recommended pressures were 30 front 22 rear cold, or 33 front 24 rear on the tire warmers, so that's what I did.

I can't get this thing to stay hooked up over pavement irregularities (which are a fact of life at Shannonville Motorsport Park). Smooth pavement (corner 1 except if I hit the "divot") it's OK. I just about tossed it away (at about 150 km/h!) when I hit that divot. There's another pavement transition at the corner coming onto the front straight that threatens to put the bike on the ground, and that's not the only other trouble spot. Even after initial install of these tires (I did two races at Grand Bend Motorplex on them) the initial impression was that the front end would slide. The general feel is of being harsh and unyielding. (It was not like that with the Dunlops)

The tire guy caught wind that I wasn't happy, and made some suggestions. Tried bumping up compression damping in the front (theory: fork bottoming, try to cushion it). Tried adding a turn of preload in front (theory: fork bottoming, try to allow more bump travel before it happens). Tried reducing rebound damping front and rear (theory: allow the tire to drop down more quickly into the dips in the pavement). These changes helped but didn't solve. Went 1.5 seconds per lap slower than last time at same track while the bike was threatening to put me on the ground, which it wasn't doing with the Dunlops.

Comments/suggestions aside from the obvious one "go back to what you know" or "switch to Pirelli" (either of which may happen)? There's another chap at the track who is faster than I am (different bike, and he is much lighter) who swears by the Michelins and swears at the Dunlops ...

Next event, in two weeks, is at Calabogie, which has much better pavement, so I will likely leave the Michelins on there for that.
 

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Established at Calabogie that the shock is bottoming, and the forks are nearly so, and that's a smooth track (a rarity in Canada). Already sent a note to my suspension guru requesting stiffer springing front and rear ...
 
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