[sportrider - tech] - DOT Race Tires and Panigale Horsepower | Ask the Geek

[Ninjette Newsbot]

Street vs. Race Tires…Again

Unfortunately, I had the experience of running over a chunk of steel on a nearby interstate on the way to work a couple weeks ago. I knew instantly that the rear tire blew out, and I hit hard enough to bend the rear rim. I am sure it does not matter which brand of tire I would have had on, but in this case I had Continental RoadAttacks and I came down to a well-controlled stop from an indicated 80 mph in traffic. I was very concerned that the front was going to go down as well but it absorbed the blow very well. My question is, do DOT racing tires have the same durability factors designed into them that street tires do? For example, are they designed to absorb any possible foreign objects or other potential damaging things such as pot holes? My last long distance ride was from Wisconsin to Deals Gap. The street tires performed well enough for me but I would not travel that far on anything but road tires because of added load and rain.
Tony Russart
Fond du Lac, WI

DOT race tires typically have a softer, more pliable construction than sport and sport-touring tires, and this could make them more susceptible to damage. To use your example, a softer carcass would likely lead to more rim damage in an impact; the tire would collapse easier. Sport and sport-touring tires generally have thicker tread than a DOT race tire, which would make them more puncture-resistant. As for load, all tires have a load index rating on the sidewall and this is typically consistent across the range of tires. For instance, your Continental RoadAttack sport-touring tires have the same load rating as the company’s SportAttack sport tires. The front tires in 120/70 size have a “58W” load index, which indicates a maximum load of 520 pounds at maximum inflation and a maximum speed of 168 mph. The rear tires in common rear sizes have a “73W” load index, indicating 800 pounds to a maximum speed of 168 mph. The race tires are similar, although in some compounds the load index is actually higher. When it comes to rain, most sport-touring and sport tires definitely offer more and deeper grooves to remove water, along with a higher silicon compound in the tread for better wet-weather performance.

Panigale Hidden Horsepower

I’ve been reading everything I can about the new Ducati 1199 because I am thinking about purchasing one. A lot of pros and cons have been said from great brakes to slippery footpegs. One I have not heard is the lack of horsepower; the only thing that has been said about the power has been about the lack of midrange. The new Panigale is advertised as 195 horsepower, however, every dyno chart I’ve seen has been approximately 145 horsepower. I hope that the bike isn’t losing close to 50 horsepower in the drivetrain. Is there any information to where the extra power is hiding?
Jarrod Parks
Pinetop, KY

The manufacturers’ claimed horsepower numbers are typically measured at the crankshaft, while almost every other reading that you find is taken at the rear wheel on a dyno similar to our SuperFlow CycleDyn unit. Most motorcycles that we test produce between 10 and 15 percent less than the manufacturer’s claimed horsepower and torque numbers, but there is definitely no set number or percentage for drivetrain losses between the crankshaft and rear wheel. For example, the last BMW we tested made 179 horsepower on our dyno, compared with BMW’s claimed 193 horsepower, about a seven-percent loss. The Ducati 1199 Panigale in our literbike shootout (“Superbike Slugfest,” Sept. ‘12) made 158 horsepower, down 19 percent from Ducati’s claimed 195 horsepower. The S model we tested in our “High-End Hardware” test in Oct. ‘12 showed 144 horsepower on our dyno, more than 25 percent down from the claimed number.

Ducati has raised some concerns about dyno testing of the Panigale, and has issued a document with guidelines that include turning the traction control off (which we do on every bike in any case) and disconnecting the speedometer sensor. We have followed the guidelines when testing the Panigale models, although back-to-back runs show that it makes little difference on our dyno. Still, we know from experience that bikes with ABS, traction control and other electronic systems sometimes do not give representative results on the dyno. Our Honda VFR1200 with dual-clutch transmission would not even turn the drum, for an extreme example.

While that may partially explain the discrepancy in dyno readings, it’s more likely that U.S. emissions laws are the culprit. Panigale models tested by European magazines generally show higher numbers than their American counterparts do, and — as we’ve seen with bikes from other manufacturers — Ducati may have had to sacrifice some horsepower in order to meet the strict U.S. sound and emissions regulations. sr

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