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Re: tyre life

Posted: Wed Aug 17, 2016 5:45 pm
by BackAtIt53
Currently the odometer reads 7280 miles on my 16 with the original PR4GTs. The rear has 6mm of good tread remaining while the front has 3mm. Getting ready to do a 5,000 mile round trip beginning Sept.05 and decided to replace the front before departing ( was having the water pump replaced, so it just seemed the smart thing to do), I will probably have the rear replaced within the next 3,000 miles, depending on wear. I keep the pressures up @ 38-39/front, 42-44 rear. Most existing mileage done commuting, so both tires have squared just a bit, but no issues other than that.
Stay safe, enjoy the ride.
8) 

Re: tyre life

Posted: Wed Aug 17, 2016 7:02 pm
by guest2360
You are obviously achieving more than the normal mileage from your tyres.  Two questions.  Fronts last better than rears but not yours. Any explanation.
Why run them with higher than recommended pressures? I have a nearly new Roadtek 01 on the rear, 1200 miles.  The central tread debts on that and it looks mint is 6mm. The same as yours with 7 times the mileage?

Re: tyre life

Posted: Wed Aug 17, 2016 7:27 pm
by Casbar
There are many tyre threads on other RT forums that recommend higher pressures for PR4GT, more so on the front. Apparently slightly higher pressures help prevent cupping on the front. The impact on slightly higher pressure, does not alter grip, well not noticeably. Michelin themselves recommend higher pressures than BMW do. I have been running 3 bar on the rear and 2.7 on the front, which is what was recommended by the manufacturer. Can't hurt to give it a try.

Re: tyre life

Posted: Wed Aug 17, 2016 8:34 pm
by guest2360
Metzler say.  "You will find the correct pressure in the operating manual of the motorcycle "  So that's easy.  They do point out that over inflation reduces the size of the contact patch.  So for me its 2.5 and 2.9.

Re: tyre life

Posted: Wed Aug 17, 2016 10:08 pm
by richardbd
BackAtIt53 wrote: Currently the odometer reads 7280 miles on my 16 with the original PR4GTs. The rear has 6mm of good tread remaining while the front has 3mm. Getting ready to do a 5,000 mile round trip beginning Sept.05 and decided to replace the front before departing ( was having the water pump replaced, so it just seemed the smart thing to do),I will probably have the rear replaced within the next 3,000 miles, depending on wear. I keep the pressures up @ 38-39/front, 42-44 rear. Most existing mileage done commuting, so both tires have squared just a bit, but no issues other than that.
Stay safe, enjoy the ride.
8)

That's a really unusual wear pattern to me!  In all my years of riding I've always had a fairly consistent ratio of two rear tyres for every one front.  What am I doing wrong??

Re: tyre life

Posted: Thu Aug 18, 2016 7:17 am
by Casbar
RTman10 wrote: Metzler say.  "You will find the correct pressure in the operating manual of the motorcycle "  So that's easy.  They do point out that over inflation reduces the size of the contact patch.  So for me its 2.5 and 2.9.

That is a good starting point, but every tyre for a particular motorcycle can not be the exact same. So some manufacturers they have different recommendations if you speak to their technical team. The easy thing and safest for the masses is stick to the manual. Having raced cars for years, 1 pound can make a lot of difference and how the car is loaded, so one pressure for all sensibly doesn't work. As for size of contact patch, that is true, but under inflation gives too much contact, and again unless all manufacturers use the same tyre compound and side wall strength, one pressure for all doesn't make sense.

Re: tyre life

Posted: Thu Aug 18, 2016 7:22 am
by guest2360
Nice to be one of the masses.

Re: tyre life

Posted: Thu Aug 18, 2016 10:38 am
by David.
BackAtIt53 wrote:Currently the odometer reads 7280 miles on my 16 with the original PR4GTs. The rear has 6mm of good tread remaining while the front has 3mm.
Looks like PR4's must have a greater tread depth from new than Dunlop RoadSmarts (I).

Had two new pairs of RS I's, the rear had 5.5 - 6.0mm & the front had 3.0 - 3.5mm, in both cases, this is serviceable tread to the legal limit, i.e. TWI.

The PR4's have the same/similar tread depth remaining after over 7,000 miles compared to the RS's from new.

Re: tyre life

Posted: Thu Aug 18, 2016 10:46 am
by guest2360
Don't believe it.  Most of us will wear out a back in 6 or 7K.  So if you start with 6mm and 6k later your down to about 1mm that would mean that BackAtIt53 started with 11mm.  That's a tractor tyre.

Re: tyre life

Posted: Thu Aug 18, 2016 11:05 am
by David.
The first pair of RoadSmarts did 5,400 miles, they were still legal with 1.6mm on the front & 1.0mm on the rear to TWI.

The second pair have done 4,800 miles with similar serviceable tread remaining.

The increased wear is probably due to a trip to Scotland, where the road surfaces are aggressive on tyres.

Re: tyre life

Posted: Thu Aug 18, 2016 4:58 pm
by Sprintgull
Change 'em or you will be constantly wondering whether they will last.  Enjoy your holiday

Re: tyre life

Posted: Fri Aug 26, 2016 1:41 pm
by Our Gee
My two pence worth on my recently changed Roadsmarts. Rear did just over 8000 miles and was well flattened off in the centre with about half a millimetre left before the TWI. Front tyre renewed yesterday due to very eneven wear pattern with poor "feel" from the front. Quite a way to go before "legal" limit would be reached. Mileage 5000. All set for an Autumn run down to Provence now.

Re: tyre life

Posted: Fri Aug 26, 2016 2:03 pm
by DaveCly
Checked my Pilot Road 4GT's this Morning 6mm left on the rear. And 5mm left on the front that's at 3967miles!

Re: tyre life

Posted: Wed Sep 21, 2016 10:09 pm
by gogs01

My Michelin PR3s have done 8000 miles, including two European tours and a lap of the Nurburgring and now measure 3mm front and 4mm rear.  Previous PR3s have been changed at up to 11,500 miles (front) and 7,600 miles (rear), but not necessarily down to the legal limit.  I'm seriously impressed with these tyres !

2013 90th anniversary edition.

Re: tyre life

Posted: Thu Sep 22, 2016 1:45 pm
by JMRT
After 5000 kms on my RT I am noticing that my front tire is starting to show signs the PR4's cupping.  I started to feel a bit of vibration and also can feel the surface is uneven on the center thread.  I always keep the tires inflated at 38psi front and 42 back.  The rear tires is in great shape but I have no idea how long the front will be usable for given how quickly it deteriorated.  I guess I will have to replace the front and run a higher psi to keep it alive longer.