Ping Dan B.

He was on DOT's
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"Andrew" <yogig RemoveThis @hotmail.com> wrote in message
news:2pblmvFj3g1uU1@uni-berlin.de...
 >
 >
 >
 >
 > He was on DOT's

DOT race tires or street tires?<!-- ~MESSAGE_AFTER~ -->
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D208 GP's, Race tires, I'm pretty sure
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"Troy the Troll" <f4boy.TakeThisOut@comcast.net> wrote in message news:<iXVXc.322839$a24.138496@attbi_s03>...
 > Any word on the particulars on your tire which caused the high side at
 > Pacific? I'm heading out to a faster track this coming weekend, still on
 > street tires, wondering how long someone can play with a hand grenade minus
 > the pin and live to talk about it.

Thought I'd follow-up last week, but blew it off. Life got in the
way. Summertime, work, riding: go figure. Now it's Sunday, first day
of rest for yours truly in quite awhile. Time to write.

Note to self: taking a tumble requires more recovery time in my
mid-30s than late-teens. Owwww. Think I'm done dirt-biking this
year, too. Oh well: "Run with the boys, walk with the men."

Following up Deerslayer's comments, the tires in question are Dunlop
D208GP-A. DOT race tires, i.e., not street.

Earlier you asked about "beggars can't be choosers" and Dunlops. At a
track event in July, I tried Tomahawk racing slicks (remolds) from
Desser Tire and Rubber, Inc. (yes, makers of the color-matched tires).
The slicks seemed a bargain. They did not prove satisfactory, so I
removed them between sessions. The "tire guy" onsite for the track
event had Dunlop D208GP-As at a reasonable price, so I bought a set.
That's all he had in race-compound tires, though there were various
street tires available. Street tires and tracks don't mix well, IME,
something we've discussed a hundred times.

I prefer Metzeler Rennsport RS-1/RS-2 or Pirelli Supercorsa SC-1/SC-2
(essentially the same tires). They weren't available. In my brief
experience, D208GP-A take longer to warm up. They aren't a "bad"
tire, just not my first choice. But between using those and sitting
out the remainder of a track day, I didn't ponder long.

The Dunlops held up great the remainder of the previous trackday, and
all morning during the last event. To be clear, these are massively
confidence-inspiring tires that stick like glue. I am not
bad-mouthing them, merely expressing a preference for
Metzeler/Pirellis. My lap times continued to drop slightly as bike
and rider warmed up, without issue.

After a long red-flag break or two, we went back out for two sessions
closely-stacked (15 min session, 15 min break, then back out for 20
min session). I fell down sometime in that second session, I'm
guessing ten minutes in. Ambient temps were up, the track felt a
little greasy. Tires, bike, and rider were quite hot. The slide
happened without any warning whatsoever.

I'd barreled through that exact line, give or take a foot, several
laps prevoius at about the same gear and speed. This time, the tire
stepped out right very rapidly. The bike tried to highside me, see
previous post. (Again, I bet it looked funny because it sure felt
like bull-riding from the saddle.)

I believe you remarked earlier, "nothing happens without a reason" and
"crashing is not inevitable." Well, the "reason" was the tires give
up the ghost, or I accelerated too hard to drive up the hill between
T7 and T8. Who knows? The "inevitable" part is another story, and
much murkier. I'm riding about as fast as I can, at a personal
10/10th. My 100% vs. Rossi's are two entirely different bars, but I'm
still moving at a good clip all things considered. The mostly-stock
bike is giving about all it can: next up are suspension mods, because
the stock units are slowing me down and not responding well enough at
this pace. If that contributed to the crash, who knows.

Not sure what else to say: I do not blame the tires. If there's any
blame, it's with the loose nut behind the bars. I wasn't doing
anything particularly right or wrong, in terms of body positioning,
acceleration, etc. Yes, there are improvements to be made in all of
the above for those last few seconds per lap, where trophies are won
and lost. Yes, crashes will happen at that pace when something fails,
for whatever reason. We accept the consequences or find something
else to do with our time.

While not a satisfactory "answer" to your questions (no stinging
indictment of Dunlop or other smoking gun, in this case), that's what
I believe occurred.

Why did I crash: total personal-best, maximum focus. I'm not out
there screwing around.

<a style='text-decoration: underline;' href="http://tinyurl.com/6k9gh" target="_blank">http://tinyurl.com/6k9gh</a>

Hope that helps,

-=DRB=-<!-- ~MESSAGE_AFTER~ -->
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 > Street tires and tracks don't mix well, IME,
 > something we've discussed a hundred times.
 >

You betcha. But juggling hand grenades while getting up to
speed can be interesting and inspirational. Until you fall
down and go boom of course.


 > The Dunlops held up great the remainder of the previous
trackday, and
 > all morning during the last event. To be clear, these are
massively
 > confidence-inspiring tires that stick like glue. I am not
 > bad-mouthing them, merely expressing a preference for
 > Metzeler/Pirellis. My lap times continued to drop
slightly as bike
 > and rider warmed up, without issue.
 >
 > After a long red-flag break or two, we went back out for
two sessions
 > closely-stacked (15 min session, 15 min break, then back
out for 20
 > min session). I fell down sometime in that second
session, I'm
 > guessing ten minutes in. Ambient temps were up, the track
felt a
 > little greasy. Tires, bike, and rider were quite hot.
The slide
 > happened without any warning whatsoever.

I see. Interesting.


 >
 > I'd barreled through that exact line, give or take a foot,
several
 > laps prevoius at about the same gear and speed. This
time, the tire
 > stepped out right very rapidly. The bike tried to
highside me, see
 > previous post.


Interesting.


 > Well, the "reason" was the tires give
 > up the ghost, or I accelerated too hard to drive up the
hill between
 > T7 and T8. Who knows?

You can eliminate accelerating too hard, because of your
statement that you were doing the exact same thing, within a
reasonable margin of error, in laps prior. So, assuming
everything else being equal, which appears to be your
recollection, the tires died on you.


 > The "inevitable" part is another story, and
 > much murkier. I'm riding about as fast as I can, at a
personal
 > 10/10th. My 100% vs. Rossi's are two entirely different
bars, but I'm
 > still moving at a good clip all things considered.

Good clips are good.


 > Not sure what else to say: I do not blame the tires. If
there's any
 > blame, it's with the loose nut behind the bars. I wasn't
doing
 > anything particularly right or wrong, in terms of body
positioning,
 > acceleration, etc.
 > While not a satisfactory "answer" to your questions (no
stinging
 > indictment of Dunlop or other smoking gun, in this case),
that's what
 > I believe occurred.
 >
 > Why did I crash: total personal-best, maximum focus. I'm
not out
 > there screwing around.

Time to speculate. I would agree that the tires died on you,
with a minor possibility floating around as well. I would
agree that such things are usually right around the corner
when zipping along at 10/10's, I would agree that sometimes
stuff happens, and it is sometimes difficult to separate one
explanation from the next when dealing with street riding
incidents, but track incidents, no lost memories, prior laps
done the same, same speed, same rider, same bike, same
track, you eliminate alot of things which are normally
hanging around interfering with trying to see what happened.

Now, the only niggling issue I've got is my experience with
tires goes against my natural instinct to say, Yup, the
tires decided to stop working. Having shagged perfectly nice
race tires in a variety of situations including but not
limited to using them beyond their useful track life, using
them after other people used them first, using them for
thousands of street miles tiptoeing around their inevitable
loss of traction, etc etc, it has been my experience that
they rarely simply stop sticking. They stick LESS than they
used to, slowly degrading into something resembling street
rubber...with less tread. I have had one of my most
interesting trackdays ever on shagged race tires because
they wouldn't stick, and the ensueing Scotty Parker
imitation I tried for the next 4 hours was an absolute riot.
Slipping into here, sliding out of half the corners on the
track, it was a riot. They got worse over the course of the
morning, but in no case was it a surprise, in no case did
they go from sticking a little to sticking not at all.

I wonder, do your suspension settings change over time, over
the course of a trackday? As the fluids heat up, as things
get warmer and looser over the course of the day, do you
find yourself adding a little compression here, a little
rebound there?<!-- ~MESSAGE_AFTER~ -->
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