Tire "gunk" question

[Eric in Davis]

These are pics of my front tire taken right after coming in from my last race of today. Is it normal to have so much build up of rubber chunks on the center of the front? I didn't pick up any of this while riding around in the pits. I believe this is pretty much how my front tire was during the race.

I don't know if it's all just "in my head", but my bike felt so unstable under braking... like I was going to lose the front. If all this rubber crud was on the center of the front tire would this explain the awful behavior I was getting while braking?

The front tire is a Bridgestone BT090 with a total of 4 short morning practice sessions, (5) 8 lap races, and a ~14 lap race. This weird behavior I described above happened on the last of those races. I dropped about 6 seconds off my normal race pace because the front felt so bad. Nothing like this happened anytime previous in the day.


edit: I was pitted right at the exit of the hot pit, so my bike only traveled a few dozen feet after exiting. Also my rear tire had basically no discarded rubber on it like the front.

http://www.bayarearidersforum.com/forums/images/threads/000/119/734/1754412-wsmc_may_2005_057.jpg

[Eric in Davis]

2.

http://www.bayarearidersforum.com/forums/images/threads/000/119/734/1754414-wsmc_may_2005_058.jpg

[Eric in Davis]

3.

http://www.bayarearidersforum.com/forums/images/threads/000/119/734/1754418-wsmc_may_2005_059.jpg

[Webdev511]

On the track, your tire is likely hot and clean. If could stop on a clean line (please don't) you'd probably see that.

When you pull off line and into the paddock you're going to pickup all kinds of junk. Stuff that lookslike blobs of rubber stuck on after the fact are just that. Get back on the track and up to speed and they will be gone pretty quick.

You probably just got unlucky and drove through someone else's gunk.

[kiltwearinfool]

+1

There's a lot of rubber that's thrown off tires during a race weekend. Especially if your class follows a big-cc class or a class with a big grid, like 600s. While the track gets swept at the beginning and end of the day, it usually isn't Zamboni'd between races.

I see this a lot on bikes during a race weekend. Funny thing is, if you were to go back to the track for a Keigwin's day, you wouldn't see as much. The track only gets swept in the morning, but there's not as many riders running on race rubber. Less "gunk" on the track.

As this rubber should be different from your tires (either in compound or material), once your rubber heats up & you do a warm-up lap it should come off and leave you clean. If you use warmers & then head out for a lap, even better.