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Be Aware- Pilot Road 3

98lee

3 Red Bricks
Staff member
I mounted a set of Pilot Road 3s on a friend's '08 K1200GT the other day. As part of the mounting, I always spray some Windex around the bead, after the tire is seated, to look for any slow leaks. The rims had been carefully cleaned and checked for nicks. To my suprise, there were numerous leaks!

Upon further inspection, after breaking the bead, it was noted that the Pilot Road 3s have the normal 1/4" "hairs" on the tread, but they also have two rows of "hairs" right next to the bead. When the tire is mounted several of these "hairs" get folded over and caught between the tire bead and the rim resulting in numerous slow leaks.

After cutting off the "hairs" with a pair of wire cutters (leaving less than 1/16") and reseating the bead, the result was no leaks.

I would suggest that BEFORE you have anyone mount PR3s, you ask them to cut the "hairs" around the bead or do it yourself. Having to add air to your tires every few days would really suck!



:dance:dance:dance
 
Good advice, Lee! It is not a bad idea to inspect all tires in this area before mounting them. I had a Pirelli Diablo with the same issue.
 
Well don't that just beat all!

Having to add air to your tires every few days would really suck!

I've just done some sloppy math and calculated I've lost 600PSI from my rear tire to date.
Compressor juice alone is not insignificant.

I just today broke the beads and cut off the short hairs to which you referred using needle nose pliers and small scissors.

Thank-you very much for this information!
I would have appreciated it even more 18 months ago but ...

Funny the front never had this issue.
 
Hi Lee,

I'm on my 3rd PR3 rear tire now, (and a lot of PR2's before these) and have never seen this. Sounds like some mold-flash that wasn't properly cleaned up during the tire manufacturing. If I had this and had bought the tire locally I would ask for a replacement. If ordered via mail-order, then I guess your solution is the more expeditious one.

I'll have to watch for this when mounting PR3's in the future..
 
Interesting - I do not doubt that the issue occurred, but I've mounted up 3-4 sets and haven't seen the issue. As another stated, somehow those missed a step in manufacturing.

But a great pre-mount check step.
 
Definitely NOT mold flash. It WAS the "hairs" or more properly the mold vents. Rims were super clean. Tire beads were super clean. All leaks were EXACTLY where the mold vent hairs were, which are spaced several inches apart. Not every place the vents were was leaking, but every place that was leaking was where a vent hair was caught in the bead.

Might be a function of hand mounting and the type of mounting bar (No Mar).

It's definitely not something that would happen every time, but you could guarantee that it would never happen by just pretrimming the "hairs".

Spoke to one of the Michelin engineers at the Rally and he said that they have not had any feedback about slow leaks on that tire, but he would look into it (yeah, right). If no one has ever had a slow leak on one of these tires feel free to ignore this suggestion, but if you have, or you want to lower the chance of a future one, this might work. Cheap insurance!

Most tires that I've been mounting don't have the vents (hairs) so close to the bead or the "hairs" are shorter.

Remember, I said "Be Aware" not "Beware". Do with the information what you will.



:dance:dance:dance
 
Yeah, they're lots shorter than the others, maybe only 1/8 inch long.

Pretty easy to go around with a razor blade and slice them off. I did it but I'm not convinced it's really a problem.
 
Not my bike. Problem was corrected. Nothing left to see. Sorry.

I understand it is too late for you, but there are a lot of PR3s on the racks out there. I have a set of PR2 (I prefer the two) but I won't be home for a week to look at them.

I have mounted tires that leak at the bead a bit. But I pump them up to about 60 psi and by morning they are fine. I assumed the bead was "seating" itself. But maybe I have been missing these hairs. I've never had a tire fail to settle in and not leak.

Nice post.
 
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