Pirelli Diablo Corsa Review, A Control Riders perspective PART II
Now that we CR’s have had some time on the Diablo Corsa tire, I thought I would pass on some of what we have learned. First and foremost, when you set the bike up right, these tires seem able to deliver nearly the SAME level of traction as both the Super Corsa and Dunlop race tire, and over a longer period of time. In fact, they inspired enough confidence that the faster CRs found themselves setting some pretty hard to follow lap times at Barber. For instance, Blandford, Garth, Peanut and some of the others, on both 600cc and 1000cc machines were dabbling in the 1:36 range with good results! To put this in perspective, many of the riders in the Advanced class were running 1:50s to 1:41s. Needless to say, these tires can turn out some very fast times!

I looked at Blandford’s rear tire (he’s on an R1 now, the bastard) all through out the day and it was exhibiting very little wear. Conversely, I totally shagged a set by noon as I had used these at VIR the prior track weekend - AT A TOTALLY INCORRECT tire pressure. This is important if you are going to use these tires. First. TRUST THEM. They are that good. Second. Believe Pirelli when they tell you to use 36 pounds in the rear. Ignoring this cost me a tire.

TIRE PRESSURE:
We have found that trying to run Race Tire pressures in the Diablo Corsa will only hasten their demise. Pirelli so much as told us this but being racers and knuckleheads many of us went our own path and used pressures far too low (and unnecessary) for the design. Going from running 30psi in the Super Corsa to 34psi or higher in the Diablo Corsa just seemed to alien too us so we stuck with what we knew - which in this case was WRONG. While traction was excellent, it soon fell off due to the abuse we were giving the rear tire, which is constructed differently than the Super Corsa and is meant to be run at much higher pressures. Street tire pressures in fact -- which in hindsight makes sense since this tire can be used with complete faith on both the street and track, unlike a race tire.

Being a little inexperienced with this, many of us chased suspension problems that did not really exist. Once the light bulb went off and we started FOLLOWING Pirelli’s recommendation for tire pressure, amazing things happened. Example: At VIR I ran 31-31 (psi) and shagged a rear tire in 1.5 days. At Barber, I replaced the rear tire and used Pirelli’s recommended pressure on the new rear. By the end of the weekend the tire still looked brand new or darn close to it. Unlike the tire I cooked at 31psi, the one set at 35psi or so just gripped like mad and never let up at the pace I was running.

I would not say the rear tire is “sensitive” to pressure settings. No more so than a race tire. Like any tire you have to be close to the recommended pressure for good wear. Pirelli often recommends 30 to 31psi for the rear Super Corsa as did Dunlop for the D208. You could go up or down a pound depending on conditions. Outside of those regions, the tires would cold tear or shag. The Diablo Corsa is no different for track use. I experimented with 31 in the rear and shagged a tire. No surprise. I was FIVE POUNDS below the recommended psi!!! I then tried 34 psi and the result was drastically better. In the end I think we can recommend fully using 35 to 36 psi in the rear tire and you can except very good traction and life at this setting.

SUSPENSION:
There are some differences in tire height between the Dunlop D208, Pirelli Super Corsa and the Diablo Corsa. As a member you will want to deal with it in one of two ways. You can either change your fork height or you can take out some preload. If making the switch permanently from D208 or Super Corsa’s to the Diablo Corsa, lower the front end 5mm and call it a day. Racers who want to use Supercorsas for racing and the Diablo Corsa for track days can get away with taking out a line or two of fork preload to gain back their steering feel. That allows you to keep your race tire suspension set up and adjust for the DC as needed. A third option, probably less ideal, is to split the difference in fork height (2mm) and then adjust preload to compensate for one of the other.

Important numbers:

Super Corsa Front: 600mm
Super Corsa Rear: 642mm

Dunlop D208 GP Front: 599mm
Dunlop D208 GP Rear: 643mm

Diablo Corsa Front: 610mm
Diablo Corsa Rear: 645mm.

As you can see, the front is really the only issue. The difference between all the rear tires is small enough you can probably get away with no changes in rear ride height when swapping to the DC. A drop of 5mm seems to be the consensus if permanently going to the DC.

In closing, after this weekend, just about every skeptical Control Rider walked away from Barber completely impressed with the over all feel, traction and longevity of the Diablo Corsa. No one expected them to be this good and give this much grip. Its nice to be surprised!!! Once we figured out what pressure the tire required, lap times started dropping into the same range as the race tires. I can say with complete belief that this is probably the BEST tire you can buy for Track Day use, bar none. It should last you longer than the Super Corsa race tire and better still, if your bike is not track-only, you can go use it on the street with out worry.

A final note: You notice I did not talk much about the Front DC tire pressure? I was running 31 in the front and it stuck like glue and wore like iron. After VIR and Barber it didn’t look any worse for wear. Pirelli Recommends 34psi in the front so that is what we’ll try next. The front doesn’t seem to much care at all what’s in it. Seemed fairly impervious. Just like the Super Corsa. Pirelli Fronts wear like iron -- with plenty of grip. However, some CRs reported a bit of pushing at 31 psi but they were riding a good bit FASTER than I was, by about 6 seconds per lap. I believe then that the recommended pressure of 34psi is what you should try. Let US, the Control Riders, be the guinea pigs. In the end though, judging from what happened with the rears, we can just about promise that 34 will be the final pressure for the front. So, 34-36 and drop the front 5mm. That’s the basics for the DC. I think we have a WINNA!!