Pirelly Sport Demon

[Tomchri]

Just saying, wortht having an extra look at your tires. Mounted late last fall, production year 20. Can't say I experienced anything like it. Will I get the same tire, NO.

Cheers Tom.

 

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[audiomick]

30 minutes ago, Tomchri said:

 Mounted late last fall, production year 20.

So they have presumably been stored somewhere for a couple of years. Since I can't imagine Pirelli producing something that developes that kind of fault so quickly, I must assume improper storage along the delivery chain somewhere.

[80CX100]

I've read about different types of dual compound tire design, almost looks like there's been a separation failure.

What I find puzzling is that the failure isn't symmetrical and even,the bottom picture looks like the failure is running right into the bead area.  wtf idk

tks for the warning & heads up

[audiomick]

7 minutes ago, 80CX100 said:

,the bottom picture looks like the failure is running right into the bead area.

Yes. What I know about dual-compound construction is that the tread area has different compounds. I've even had tyres on which one could clearly see the delineation between "sticky for cornering" and "hard for durability". I can't imagine why there would need to be a compound mixture in the sidewall, particulary one that is not evenly distributed all the way around.

[Tomchri]

Def a major production fault. It shoud have survived 2 years just left outside in the weather, I think.    Glad I spotted it. Lawyer food. It actually had cracks 3 places. 

Cheers Tom.

 

[Tomchri]

What, What, another Pirelly Sport Demon with the same fault . Tire looks fine when mounted, a week later when filled with air cracking showes.
Cheers Tom.


Sent fra min SM-S906B via Tapatalk

[Speedfrog]

It is odd the way they crack in a long fine line but not really following any markings on the sidewall or it’s radius.

Is the last one from the same batch as the first? Bad compound on a small batch series?

I would contact Pirelli and take those back to the place of purchase.

And stay away from them Demon-iac hoops!

[Tomchri]

Both Brazil made, aug and sep 20.  I have 1 more Demon spare, made in Indonesia. Feels a bit different, but NO, will not be mounted. Known the tire dealer since early 80, so no problem there.   I might send the pictures to Pirelli if doable. D not acceptable for a bike tire.

Cheers Tom.

[p6x]

This is really strange. The place of manufacturing does not usually change anything to the quality of the compound.

In a tire thread, we discussed how important the storage of rubber/elastomere compounds is critical. The tires should always be left in their individual wrapping, and stored in a temperature controlled environment until they are ready to be installed.

Another possible issue is the vulcanization process. Temperature and time are so important.

When I was a student, I visited the Michelin Plant in Clermont-Ferrand. The guide told us that any breakdown in the process equates to failing QA/QC and resulting in discarding.

You should definitively have your dealership to make contact with Pirelli to make them aware.

[Tomchri]

My 1000 S came with Demons made in 2012. Almost like new, but to old for my liking. So much for getting new tires 

Cheers Tom.

[p6x]

16 hours ago, Tomchri said:

My 1000 S came with Demons made in 2012. Almost like new, but to old for my liking. So much for getting new tires 

Cheers Tom.

As with any other rubber, there is a shelf life, beyond which the tire's performance is no longer per specification. The shelf life of an o'ring is written on the package. Parker specifies that an open package should be used quickly. Storage conditions too. And of course, in an opaque environment.

I have discussed this here with the tire shop where I get my car tires. I always order my tires. I don't like how they store theirs.

[LowRyter]

@p6x

I have to agree.  I took off a rear tire that was about have done off my Sport in anticipation of a trip.  After the replacement wore out, I reused the take off.  Man, that tire was awful.  Despite storing it on my garage for a couple of years, it was really bad.  I lost $ more in the mount and balance than I ever saved.  But it was actually worse than the tire I took off.