Michelin pro 4 endurance failure?

sunnyrider

hi all,

I have a set of Michelin Pro 4 endurance tires on my bike. I put them on 2 years ago and never rode on them... I'd like to start riding now but I notice there are countless red bumps on the tire walls (a few are clearly very small bubbles).

I can rub them off but am concerned mostly about the tire safety. has anyone seen this happen before? is the outer wall porous enough to allow the interior layer to leach out?? They are holding air as normal.

I emailed Michelin about it asking what it could be and if they're covered, but they just said to have them checked out.

I'd hate to throw them out but if there's a risk of failure while I'm riding I'd rather do that.

https://flic.kr/p/TSD9zf

thanks in advance for any advice or knowledge.

sungod

it's been reported on various michelin tyres, seems benign, for instance...

http://weightweenies.starbike.com/forum ... p?t=142729

sunnyrider

thanks! I tried to do a search online but couldn't find anything. the photo matches mine, and seeing that I haven't put a km on mine, I'd say it's a missed quality control issue. as long as I don't have a blowout at high speed, I'm alright with it.
a bit disappointed in Michelin for not even attempting to give me an idea though...

pippi_langsamer-2

Very interested in this.

MP4E's have been my go to tyre for years, but I only recently binned one of my tyres because of this exact "phenomenon", with the weird pink stuff. Tyres were on my Addict and were fitted last beginning of last year and were fine throughout the year. It was only post-winter that I got the Addict prepped for a ride that I noticed the tyre guff. What worried me was the fact that ( as reported on the WW thread), any attempt to remove the guff seemed to result in rubber underneath slothing off the tyre to the point I didn't trust inflating it, never mind riding it.

Certainly won't put me off buying the tyres, but it would be good to know why exactly some of the are doing this, and indeed if Michelin are prepared to replace any that exhibit "pink guff"

priory

I put a pair of these on and 200miles later a very ordinary pebble slashed the front sidewall.So I put the vitt zaffiras back on. However recently ,the zaffs having eventually worn out, I bought another mich and put them on for another try. The lighter and more flexible the tyre the more it costs, the ride is perhaps slightly smoother, more punctures and less milage.Unless you really are in a race the cheap tyres are probably the more efficient choice.

sunnyrider

I agree about inexpensive tires, but I got these when I *had* the money to. I once had ultramos and as soon as I rode on them I thought, "aaaahhh, so this is what money buys". not being a serious rider that packs on the mileage these days I didn't mind spending the money, as I figured they'd last a long time... I'll just ride on these carefully, and I'll give an update if that was a bad choice!

re: storage, I had these indoors the whole time. the room wasn't heated much, so maybe that played a role.

step83

Noted this on a patch on the front of mine, I thought id gone over something an not noticed, probably covered about 1800 on them wearing nicely bar this new oozing spot something ill have to keep an eye on!

imafatman

Rubber slowly perishes, leaving them lying around for years is going to have an effect.

pippi_langsamer-2

imafatman wrote:

Rubber slowly perishes, leaving them lying around for years is going to have an effect.

Agreed, but it's not natural perishing. I have a few older P4E's hanging around my garage- including two on my old winter- now turbo delegated bike. The rubber on these is fine (albeit turbo ravaged). The P4E I noticed the pink guff stuff on was on a much newer tyre that showed little sign or no sign of perishing except under these isolated pink spots.

I'll be keeping an eye on the most current P4E I bought to replace the affected one.