Flogging A Dead Horse

[faffi]

I know my interests are somewhat peculiar, but when I noticed that there was more than 8.5 seconds difference in lap times between a Pirelli Diablo Supercorsa SP and a Shinko 005 Advance fitted to a CBR1000RR circulating Willow Springs - http://www.motorcycle-usa.com/545/8285/Motorcycle-Article/2010-Street-Motorcycle-Tire-Comparison.aspx - I couldn't help but think way back when. The difference between a 1997 Ducati 916 (as well as the GSX-R750) and an old Honda CBX six - obviously not tested on the same day - was 15 seconds out of which around 4 came from track improvements, making the difference perhaps as little as 11 seconds. The two '97 models were riding on Dunlop D364 tyres, perhaps the stickiest street legal rubber of its day. The CBX ran narrow stock tyres fitted to 2.15 in narrow rims.

 

Considering the advancements done regarding suspension, power, weight, handling and tyres, it isn't surprising that the bikes from 1997 were significantly quicker than those of the 1977 CBX. But that tyres alone could produce lap times of such difference today wasn't something I expected at all.

 

BTW, does anybody know if Willow Springs have been changed (to the worse) since 1997 when it comes to lap times? In 1977, Cycle set a 1:43 on the CBX. On the improved track (smoother, grippier asphalt and some slightly altered corners if memory serves) Cycle World posted 1:28 laps with the 916 and Gixxer. However, in 2010, Motorcycle USA could only muster a 1:31.5 on the Pirellis and 1:40 on the Shinkos. Whatever the reason for the differences, be that lesser riders or different track layout, my "statistics" should still be valid.

 

Anyway, if you find these things interesting, please chime in. If not, well, at least I did

 

 

[Cobie Fair]

The track has undergone some slight changes, and the times dropped a bit due to that. Way back when, Eddie Lawson did a '25 on a GP bike, and that stood for some years. Now I'm not sure what the record is, last time I was paying attention to that it was an '18 on a Superbike by Steve Rapp.

 

Anyone know the current record, and the years of the repaving/changes?

 

CF

[faffi]

Er, this is definitely present and track oriented - I simply mentioned the old figures as a reference to why I found a 9 second difference in lap times on current tyres fitted to the same time surprising. I wouldn't expect such a big difference between a modern touring radial and a street oriented sport tyre, in fact.

[Cobie Fair]

Er, this is definitely present and track oriented - I simply mentioned the old figures as a reference to why I found a 9 second difference in lap times on current tyres fitted to the same time surprising. I wouldn't expect such a big difference between a modern touring radial and a street oriented sport tyre, in fact.

 

Eirik,

 

Kind of interesting comparison, isn't it?

 

CF

[faffi]

Well, obviously I think so

 

But if the time differences are real and also if the track from 1997 can be reasonably well compared to today's version, that means that A) a good rider on a 1997 bike fitted with 1997 tyres will be considerably faster than a mediocre rider riding some of the best equipment available in 2010 and B ) that even a rider that's not stunningly fast can benefit greatly from using grippy tyres. I've sort of lived under the impression that tyres, at least the grip they can offer, doesn't really start to matter until you get pretty darn fast, but it seems I'm wrong. Either that, or the test results were staged in some way, which I find unlikely.