Michelin PR 4 vs. PR 4 GT

patm said:

The original Metzeler Z8 that came with my RT had a darker band as a wear indicator.

Click to expand...

Most tires have a silver stripe as a wear indicator

here are images of my Michelin tires' tread wear indicators...

PR4 NOT the GT version with the TWIs being about 1.125" apart AND with a TWI in the middle of the siping...



and the Road 5 with the TWI dimples being 1.25" apart....



while not exactly in the center of the tread they are pretty damn close....

wyman.winn said:

while not exactly in the center of the tread they are pretty damn close....

Click to expand...

But not pretty damn close enough. You'll get the silver stripe indicator first.

beemerphile said:

You'll get the silver stripe indicator first.

Click to expand...

and you know this for certain on the Road 5 tires....dang, you do ride a lot....they were only released on January 1st...!!!

Lee said:

Most tires have a silver stripe as a wear indicator

Click to expand...

Lee said:

Most tires have a silver stripe as a wear indicator

Click to expand...

OK. But for how many miles does this silver stripe show. If I am here in the Big Bend, headed to your house - 800 miles - and I check for the silver stripe when I leave here and see no stripe, will I make it to Engles before I have a problem? Curious.

I have Pilot 4 tires with angled wear like they were on severely slanted slab for 12 K miles in 3 years. The center is great, the cheeks are my concern.
Should I replace these?

Jim S
Long Island



Sent from my iPhone using Tapatalk

jsoque said:

Should I replace these?

Click to expand...

Is this a serious question?

Lee said:

Is this a serious question?

Click to expand...

It was a test, and you passed!
I have never had such serious side wear before and I guess cornering on wet pavement “could be” an issue.
Thanks,
Jim


Sent from my iPhone using Tapatalk

It looks like a lot of miles underinflated to me.

That picture shows the same sort of wear I've had on PR3 and PR4GT tires, and I'm beginning to see similar wear on a Metzeler RoadTec 01. Seems to be typical of tires that use two tread compounds. My front tires have been kept at 40 psi to reduce cupping, so not under-inflated. The "step" develops at the transition between the center tread compound and the softer side compound. Could probably be reduced by not hitting the corners so hard, but where's the fun in that?

The wear is a little unusual in that the left side (from the rider's perspective) usually wears faster. In that picture, it looks like the right side is more worn.

That tire is well past due for replacement. I'm into the wear indicators by about 9000 miles on the Michelins.

lkraus said:

Seems to be typical of tires that use two tread compounds. My front tires have been kept at 40 psi to reduce cupping, so not under-inflated. The "step" develops at the transition between the center tread compound and the softer side compound.

Click to expand...

My wife and I get the same step with dual compund tires.

34 round town, and 40 on the highway

PGlaves said:

It looks like a lot of miles underinflated to me.

Click to expand...

Hi Paul,

I respect your input and thank you.

Around town I'm at about 34 lbs psi for both, and with loaded bags for a long trip, 25 lbs x 2, and 35 lbs x 1, it was suggested I take both tires up to 40 lbs psi for both.

Softer sidewalls are just about my only explanation for the unusual tread wear.

Honestly, this ones' a first for me otherwise I wouldn't be crying 'No Joy'.

Pilot 4's on order now and will be mounted after I come back from a business trip.

Jim

I would think 36F/40R with light loads and 38F/42R for heavier loads would be close to the ticket. I have always run more pressure in the rear. You could always do the research based on the pressures that give you a certain pressure increase from cold to hot. Some references say 10% rise, which may be the number for best performance, but I use a simple +2psi instead (closer to 5%) as I think the performance is still fine, but the tires last longer with the higher pressure.

Funny thing, on the current bikes with wide radials, that drill keeps coming up with the numbers I posted above.

jsoque said:

...Around town I'm at about 34 lbs psi for both, and with loaded bags for a long trip, 25 lbs x 2, and 35 lbs x 1, it was suggested I take both tires up to 40 lbs psi for both.

Softer sidewalls are just about my only explanation for the unusual tread wear. ...Jim

Click to expand...

Jim, IMHO, you should probably stick to the recommended pressures for the bike you're putting the tires on. 34 psi isn't too far off for the front tire, but way under-inflated for the rear. Everything I've seen says the front should be at 36 psi and the rear at 42 psi. I've seen only one tire manufacturer recommend 40 psi for the rear on my bike.

But what works for mine, may not be what is recommended for yours. You need to check your owner's manual.


Some people recommend increasing the front tire pressure to eliminate cupping. Frankly, I've never had enough cupping on a tire to feel it before needing to change tires for wear.


On a previous bike, I thought I'd get more tread life by increasing the rear tire pressure by another 4 psi over the manufacturer's limit. What I found over several tires, was all I succeeded in doing, was to make the ride stiffer. At the recommended tire pressures, the tires lasted just as long.

Chris

One final point is that with $5 pencil gauges The graduations are imprecise and it is difficult to find two that will give the same reading within 2 psi. You can also be led astray by digital gauges that read to a tenth, but are no more internally accurate than a cheap plastic body pencil gauge. I have a Milton pencil gauge that beats some of the electronic wonders that have passed through my shop (and out by way of the garbage can). So, if 2 psi makes a significant difference, then 2 psi with which gauge? Some of the TPMS systems have temperature compensation which if you have one of those can leave you trying to correlate a (possibly inaccurate) gauge to a somehow compensated TPMS reading. Some digital pressure gauges are temperature compensated, but to the ambient temperature and not the temperature of the air in the tire. So reference points can vary as much as internal accuracy and reading precision.

One simple path to success would be to set the tires to the manufacturer's recommended pressure with an accurate tire gauge and motor on. For an accurate pencil gauge with 90 degree head try this...

https://www.amazon.com/PCL-Passenger-Pressure-Gauge-TPG1H17/dp/B0107WNRSW#customerReviews