Only 23 days left until WSBK starts!

[gm2]

Which issue of RRW?

march 2010.

good article but easy to summarize:

Pirellis = soft carcass.  don't like tons of load, so requires the rider to point-and-shoot ("superbike") the corners.

Bridgestones = hard carcass.  requires tons of load to work correctly, therefore requires the rider to maintain a lot of corner speed.  so you get 800cc* GP riding; a lot like the 250s and a lot of follow the leader.  yawn.

i mentioned JT because in the article there's a quote from The Ben saying that 4 years was probably too long to spend on the Pirellis, which was why JT didn't do so well in GP [once he got off the michelins].

the article is about the fact that this single issue is why the two series are so different.  the bikes themselves aren't too far apart really: superbike = 215 hp, 356 lbs; motogp = 225 hp, 330 lbs.



*another piece of the perfect storm of tire events when GP went to the 800s.  due to being down on power and the peaky nature of the new bikes, everyone increased their corner speed.  the racing got boring and the softer construction tires (michelin) started to suck.  soon everyone wants to be on the Bridgestones, rossi moves, pedro moves, the whole paddock goes Bridgestone spec... thereby requiring the style of riding that they're now trying to remedy (among other things) with the move to 1000cc.

[ducpainter]

So...

Does the Bridgestone deal expire with the 1000cc switch?

[BastrdHK]

mechanical at imola.  gearbox went kaplooey.

http://www.motomatters.com/results/2009/09/27/2009_imola_world_supersport_race_result_.html

[gm2]

http://www.motomatters.com/results/2009/09/27/2009_imola_world_supersport_race_result_.html

yeah, but i think he crashed because of the mechanical.

[BastrdHK]

No, he lost the front at about 130 into a downhill right hander....very fast....definitely not a mechanical failure.

[derby]

yeah, but i think he crashed because of the mechanical.

you sure that wasn't magny cours?

[gm2]

you sure that wasn't magny cours?

laverty fell off at magny-cours, didn't he?

i for sure remember reading mecahnical + Imola.  i may have been drunk.  who knows.

..oh wait:  this isn't where i (may have imagined that i) saw it originally, but:

http://en.wikipedia.org/wiki/Cal_Crutchlow

He finished in the top four at every race until a mechanical failure while leading at Brno, and found himself in a two-way championship dice with surprise package Eugene Laverty on a Parkalgar Honda. Crutchlow lead the championship easily until a gearbox failure while leading at Imola meant that Eugene Laverty moved to within 3 points.  However, at Magny-Cours after an intense start it was Laverty's turn to have some bad luck, falling off, but picking his bike back up to leave him 19 points behind Cruthlow with 1 race at Portimao left.

[fastwin]

2010 WSBK preview video.

http://www.roadracingworld.com/news/article/?article=39402

[Speeddog]

~SNIP~

Pirellis = soft carcass.  don't like tons of load, so requires the rider to point-and-shoot ("superbike") the corners.

Bridgestones = hard carcass.  requires tons of load to work correctly, therefore requires the rider to maintain a lot of corner speed.  so you get 800cc* GP riding; a lot like the 250s and a lot of follow the leader.  yawn.

~SNIP~

Having trouble wrapping my head around that.
Not due to the conclusions, just can't see how the carcass effect would be that way.

[Jester]

Having trouble wrapping my head around that.
Not due to the conclusions, just can't see how the carcass effect would be that way.

Rossi has been quoted in an interview before while speaking on the Stones.  He commented about the same.  He said the require the rider to keep them heavily loaded during all phases of the corner, so you have to keep steady speed, but not upset the bike or you'll lose a lot of time.

If you poke around, back when Michelin used to do their one-off specials for every race, Rossi's tires were a much stiffer carcass then what other michelin riders used.  Edwards onced commented that he didn't understand how Rossi rode his tires, because they were stiff as a brick and Edwards couldn't get the same performance out of them when he tried them.

[DesmoDiva]

14 Days!!!

Woot!   

I can't wait.    [moto]

[gm2]

Having trouble wrapping my head around that.
Not due to the conclusions, just can't see how the carcass effect would be that way.

my interpretation means i probably should have said in order to get maximum grip.. for both cases.

too much sustained heavy load, the softer construction tires give way.  not enough sustained heavy load, the harder construction tires don't perform.

(in my muuch less sophisticated track riding) i've seen the same thing with certain tires.  they sucked until i started to go fast enough, long enough.

back when Michelin used to do their one-off specials for every race

that's a bit of an exaggeration.  

[Triple J]

Having trouble wrapping my head around that.
Not due to the conclusions, just can't see how the carcass effect would be that way.

Seems like a heat issue to me since tire flex equals heat.

Soft carcas = more flexible = more heat generated in the tire under sustained load, which frys the tire.

Hard carcas = less flexible = less heat generated under sustained load, meaning sustained load is necessary to keep tire at optimal temp.

[Speeddog]

The area that's really giving me trouble:

I'm assuming that there is some optimum stiffness of tire, or a least a 'good' range, the stiffness being a combination of carcass and air pressure.

A soft carcass tire would run higher pressure than a hard carcass tire to get the same stiffness.

[derby]

Seems like a heat issue to me since tire flex equals heat.

Soft carcas = more flexible = more heat generated in the tire under sustained load, which frys the tire.

Hard carcas = less flexible = less heat generated under sustained load, meaning sustained load is necessary to keep tire at optimal temp.

...and then you have the issue of compound and how it interacts with the above.