Pirello to Bridgestone (review)

Randy Grein randygrein at comcast.net
Tue Aug 19 21:37:05 PDT 2008

Check the swingarm angle - you might be able to increase rear height  
Randy Grein, WMRRA #41

On Aug 19, 2008, at 9:31 AM, Jo Rhett wrote:

> I'm not certain I can.  With the GSXR front it's pretty low, and a  
> couple millimeters will probably have me dragging the belly pan.   
> I'll give it a try though.
> On Aug 19, 2008, at 12:07 AM, Randy Grein wrote:
>> Thanks for the review Jo. You might try dropping the front a couple  
>> of millimeters to get the front to track properly again - just an  
>> idea, I've not heard the Dunlops were prone to understeer but I've  
>> not considered them for about 4 years - since a friend wore out a  
>> front in 1 race.
>> Randy Grein, WMRRA #41
>> On Aug 18, 2008, at 11:32 PM, Jo Rhett wrote:
>>> So Friday at Infineon was just me having fun, as I wasn't going to  
>>> race that weekend.  All morning I was having trouble lighting up  
>>> the rear, nice fun slides out of every fast corner - 2, 3, 3a, 4,  
>>> bottom of the Carousel, you name it.  Not surprising given that I  
>>> had 3 race days, 4 practice days and 3 track days on the set of  
>>> tires.
>>> At lunch I replaced the soft/soft Pirellis with soft/medium  
>>> Bridgestones just to have some fun.  I've got 5 trackdays before  
>>> the final WERA race, so why not fart around and see how I like the  
>>> tires?
>>> I actually dropped out of the A Race group figuring that switching  
>>> tire brands would slow me up for the rest of the day.  I went out  
>>> behind a moderately fast guy to pace myself and not get stupid,  
>>> but felt so good I passed him entering the Carousel and never saw  
>>> him again.  My 4th lap on the new tires was 2/10ths of a second  
>>> faster than I did on the Pirellis all morning (as well as all  
>>> succeeding laps).
>>> First impressions:
>>> * the profile is different, and my first thought was that the  
>>> tires actually "rolled better".   Especially on corner exit, the  
>>> bike seemed to be moving faster right away.
>>> * On corner entry the tires held awesome and solid.  I really had  
>>> to work to get the front to push, and I never successfully spun up  
>>> the rear.
>>> * Just like the Pirellis, once I had turned in the bike was stable  
>>> and solid, completely reassuring.
>>> However, it wasn't all good. My perfect suspension from the  
>>> morning was gone.
>>> * The bike seesawed mid-corner (fixed by adding rebound to the  
>>> front and taking some out of the rear)
>>> * The front under shuddered under hard braking, fixed by adding  
>>> rebound to the front but it came back as soon as I went faster  
>>> again.
>>> * The tires exhibit the Dunlop "drift".   Unless you push the  
>>> front, a Pirelli will exit the corner *exactly* where you think it  
>>> should.  The Bridgestones exhibit the Dunlop Drift where you find  
>>> yourself just a foot wider than you expected exiting the corner,  
>>> but you didn't push the front.  The whole bike just ... drifts a  
>>> bit.  I hated this on the Dunlops (which is why I went to Pirelli  
>>> in the first place) but this appears to be evident in the  
>>> Bridgestones too.  *shrug* For now I'm just riding it.
>>> Next stop: Miller Motorsports Park, Utah.  I'm returning after a  
>>> fairly successful weekend on Pirellis there, we'll see how the  
>>> Batlax holds up.
>>> -- 
>>> Jo Rhett /  velociRaptor Racing
>>> #553 WERA / AFM
> -- 
> Jo Rhett /  velociRaptor Racing
> #553 WERA / AFM

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