PR4 Disappiontment...

[Phil Tarman]

I've got a PR4 rear tire that's got about 8,000 miles on it and I don't think I feel confident riding to the National Rally on it. I'm going to replace it with a used PR4 that's probably got 6K on it but has way more tread left.

Is anybody else getting such low mileage from the PR4 rear?

 

[JQL]

Re: Disappiontment...

There are a number of factors which could contribute to high tyre wear (I hope I'm not teaching anyone to suck eggs ):

1. Road surface - an abrasive surface will wear the tyres more quickly.
2. Inflation - under inflation will wear the tyre more quickly as the tyre runs hotter and more of the tyre is in contact with the road.
3. Riding style - hard acceleration and high speed both heat up the rear tyre making it run hotter as well as abrade the tyre more quickly thereby shortening its life. Frequent hard braking will do the same for the front tyre.

On another board, one of the members used to work for Michelin and his recommendation is to run the tyres slightly over-inflated. His recommendation is for 2 psi over-inflation (cold tyre) on both front and rear. I have found that I prefer just 1 psi on the front and 2 psi on the rear over-inflation. He also recommends not going higher than 2-3 psi.

I have done about 8,000 miles on my PR4 rear and it's about 1/3 worn.

Wear on a PR4 Rear fitted December 2014 approx 8,000 miles

 

[Macka]

Re: Disappiontment...

I have only about 5000km (3200 miles) on my PR4s and I am not overly happy with them.
The grip level seems to be OK although I have had it feel "vague" a couple of times on fast wet bends.
The rear tyre is noticeably "squared off" already. The front one seems to be wearing evenly but has already lost nearly 1mm of thread.
I always run them 2-3psi above the Honda recommended figures.
The main problem I have with them though is the noise factor. As they wear they are becoming very noisy. Many of our road surfaces in Southern OZ use "course-mix" bitumen and the surface is very aggressive on tyres. On a smooth surface they are very quiet but on a coarse surface they "rumble" quite loudly. It is clearly audible above my music and wind noise.
The first time I noticed it I thought that one of the pannier lids might not have been closed properly. It is that hollow, plastic, rattling type of sound.
I suspected all sorts of other possible causes and it took a few rides to track it down to the tyres.
The old tyres that came off were Michelin Pilot Active and although I was never confident in the wet they did 27,000 km (17,000 miles) with still about 2-3,000 km left and they were absolutely quiet.
I chose the PR4s to get the best possible wet grip but at this stage I am not sure that I would buy them again next time.

Macka

 

[DirtFlier]

Re: Disappiontment...

High ambient temperatures can also increase a tire's rate of wear.

 

[Macka]

Re: Disappiontment...

High ambient temperatures can also increase a tire's rate of wear.

3500km of the 5000km have been at less than 25 Degrees C (about 80 Degrees F) so that is not a factor for me.

 

[mikesim]

I've got a PR4 rear tire that's got about 8,000 miles on it and I don't think I feel confident riding to the National Rally on it. I'm going to replace it with a used PR4 that's probably got 6K on it but has way more tread left.

Is anybody else getting such low mileage from the PR4 rear?

You might document the date codes on both and drop Michelin an email about the problem. Maybe they changed rubber formulations or had a bad batch of rubber that slipped thru their QA process. If so, they might help you out with a new tire. Sounds strange to have two seemingly identical tires wear so much differently.

Just my .02

Mike

 

[charlie b]

Phil,

Didn't your first pair last a bit longer? Wonder what the difference was from. Maybe you got one of the first batches of PR4's and they changed them for some reason?

The PR3's were the first tires I ever owned that were still round at 8k mi.

 

[Miairhead]

I just took off my '3's because of a long trip coming. I was still riding around home I left them on, got 11K, and front was good, back close to indicators. I hope the4's do that good, too. I use to getting about 7 on my R100RT narrow tires, so near twice is great. I do run a little more air in them.
I will be very disappointed if I don't get 10K out of them, gravel road, and Michigan's excellent roads can shorten life of everything. Living on a gravel road does make breaking in the tires rather quick, still first 100 it even slower cornering.

 

[JohnC]

The FJR forums are also sometimes reporting high wear rates on PR4's. On the other hand, the FJR is heavier, more powerful, and in many cases ridden more aggressively. I am in the process of putting new tires on my bike. After a lot of thought, I opted for Bridgestone T-30 GT's.

I am planning on Spearfish, then three weeks later, Lobster-STOC in eastern Maine with a side trip to the Dragon and the Smokies on the return leg. I will see how the tires hold up.

 

[Comanche]

i got 13,600 on my last rear PR4, which was not substantially different from the previous PR3. That's in high Texas heat, chip seal road surfaces and 75-80 mph speeds.

Strange you should get such low mileage, Phil. I like the suggestion of noting the date code and telling Michelin.

 

[Bear]

John, When you get to Maine, give me a call. We have great lobster in Penobscot Bay.

 

[junglejim]

This thread inspired me to go check my tires (PR4s). Results below.

I have about 4K miles on mine and the rear tire is down to a total tread depth of less than .110" and only about .0900" to the wear bars. If I prorate the wear rate I'll get about 14K out of the rear if I keep it that long. I believe they start with 5/32" (.1563") of tread, .1250" of which is usable to get down to the wear bars.

Tread depth measurements of the front tire are almost identical to the rear. They were put on at the same time.

 

[Phil Tarman]

I'm going to replace my rear tomorrow with another PR4 that had about 4-5K on it when we left on the Epic Ride.

 

[junglejim]

Just talked to my son who is trying a set of Bridgestone T30s. He has 2400 miles on them now and his tread depth is .175" which is more than I started with on my PR4s. His last tires were PR4s which gave him about 8,000 on his C14. He prefers the Bridgestone T30s over the PR4s. BUT he switched from a 50 profile PR4 to a 55 profile BT30 and that may account for the better handling as much as the tire itself. The higher profile fixed the speedometer error too.

 

[Macka]

This thread inspired me to go check my tires (PR4s). Results below.

I have about 4K miles on mine and the rear tire is down to a total tread depth of less than .110" and only about .0900" to the wear bars. If I prorate the wear rate I'll get about 14K out of the rear if I keep it that long. I believe they start with 5/32" (.1563") of tread, .1250" of which is usable to get down to the wear bars.

Tread depth measurements of the front tire are almost identical to the rear. They were put on at the same time.

Hey Jim, in your attached pic it looks like there is some scalloping on the sipes. Is that correct?

Macka

 

[junglejim]

Hey Jim, in your attached pic it looks like there is some scalloping on the sipes. Is that correct?

Macka

Yes, the tires on both ends are getting cupped. I've had Dunlops, Avons, Bridgestones, and Michelins and they have all cupped to some degree, some worse that others. I'm not an aggressive rider and the pressure is set at or about 1# above spec. Most of my riding on the tire shown in the picture was on asphalt and concrete roads in WI. No high temperature chip-and-seal pavement. They were put on last September and ridden about 2 months in the fall and again for two months this spring.

Does anyone know the tread depth of a new PR4???? They don't want to publish any tread depth data that I can find. A lot of street bike tires are 5/32 when new. Some are more.

 

[Macka]

Yes, the tires on both ends are getting cupped. I've had Dunlops, Avons, Bridgestones, and Michelins and they have all cupped to some degree, some worse that others. I'm not an aggressive rider and the pressure is set at or about 1# above spec. Most of my riding on the tire shown in the picture was on asphalt and concrete roads in WI. No high temperature chip-and-seal pavement. They were put on last September and ridden about 2 months in the fall and again for two months this spring.

Does anyone know the tread depth of a new PR4???? They don't want to publish any tread depth data that I can find. A lot of street bike tires are 5/32 when new. Some are more.

I measured my new PR4s the day they were fitted. The front had 3.5mm (9/64th" or 0.1378") to the tread wear bars, measured at the tread centre. The rear had 6mm (15/64th" or 0.236") measured at the tread centre to the wear bar and 5mm (13/64th" or 0.197") measured on the side to the tread wear bar.

Macka

 

[junglejim]

I measured my new PR4s the day they were fitted. The front had 3.5mm (9/64th" or 0.1378") to the tread wear bars, measured at the tread centre. The rear had 6mm (15/64th" or 0.236") measured at the tread centre to the wear bar and 5mm (13/64th" or 0.197") measured on the side to the tread wear bar.

So, based on your information, my PR4 rear tire is about half worn out at 4,000 miles.
That is about what Phil experienced too.

The previous PR4 went about 12,000 miles and could have gone a little longer.

 

[dnktng]

Included in the "riding style" factor for rear tire wear should also be how much rear brake you use. Not sure how big of a factor it is, just something to consider since some riders say they don't use the rear much. I'm pretty good at consistently using both brakes to slow and finish with the rear only, so I would think I'm in category of a "moderate to heavy" rear brake user. I don't think I'll change my riding style to increase the life of my rear tire.

I have 5600 miles on my rear PR4 and it has 3.2mm at the center tread wear bars. Thanks to Macka reporting a 6mm initial depth, I should get about 12000 miles. I got 9000 and 12000 on two PR3's. For me, the PR4 isn't a dramatic improvement over the PR3.

 

[JQL]

When braking the rear brake makes up about 33% of the braking force. So one could say that the tyre will wear 66% less under braking. This, of course, is not actually true because you are more likely to "unload" the rear tyre under braking making it more susceptible to sliding even if only very slightly or virtually un-noticeably adding to the wear. So, for the sake of argument lets change that to 50%. Also the rear tyre is also wider so can should handle the braking wear better so lets make that 55%.

The rear tyre does take more wear under acceleration, how much depends on your style of riding. I tend to accelerate quite quickly up to the limit then hold the limit. This is because some experiments in the 1990s seemed to suggest that this form of driving/riding was, overall, more economical.

My braking style is similar to that of DNKTNG

For all these reasons my rear tyre tends to last only about 66% the life of the front.

Your mileage will vary!