We Need to Talk Pilot Road 4...

[Guest Kakugo]

I've installed a set of Pilot Road 4GT on my 2009 RT. They have a tad over 1000km now in various conditions.

 

So far I am not overtly impressed with them and wondered if I am doing something wrong. I have been running them at the usual Michelin suggested pressure of 2.5 bar front and 2.9 bar rear. No possibilities of suspension adjustment as I have ESA.

 

What really bugs me is the rear. It bounces around far too readily and seems to fall into corners much faster than the front, never a good thing.

 

I have devised endless horrific causes for these rear end issues, from some catastrophic impending final drive failure to issues with the (freshly rebuilt) rear shock.

 

Any comment from anybody with these tyres would be greatly appreciated.

 

 

 

[biometrics]

What really bugs me is the rear. It bounces around far too readily and seems to fall into corners much faster than the front, never a good thing.

 

 

Sounds like classic underinflation symptoms to me. I don't know how your "bar" measurements stack up to pounds of air pressure, but try running 40 lbs. front and 42 lbs. rear and see if that improves your tire performance and feel.

[Glenn Reed]

From the all knowing google -

 

1 bar = 14.5037738 pounds per square inch

 

so 2.5 bar front works out to 36.25 psi, and

 

2.9 bar = 42.06 psi.

[RTJohn]

Max cold pressure front and rear, all the time, no problems.

[Guest Kakugo]

Thanks for the replies.

 

I have three tyre pressure gauges at home, plus the "Professor" (TPMS) on the bike, so getting pressure wrong is not very much an issue.

I am beginning to suspect either I got a dodgy tyre (I've had a single one in decades of riding so far) or, more likely, there's something wrong with the bike... but what? When the tyres do not "act up" (another issue is they seem oversensitive to tarmac quality) the bike feels like a dream.

 

[SinNH]

I can certainly see why you say the rears falls into corners faster than the front because I went to a tech day last weekend and a fellow mounted a PR 4 rear on his machine and the first thing I noticed was how "pointed" it was----- with 42 PSI.

[Alfred02]

I have had PR3's on the 2005 Hexhead and now PR4's on the 2014 Wethead.

No issues at all, even at hard low cornering, keeping up (in corners, not outright acceleration) with CBR's and other sportbikes on an RT.

So as you said. Either one off tire issues or some kind of drive/suspension problems.

Your tire pressures are fine as that is what I am using on the Wethead, so that's not the issue.

 

Some observations:

 

1) your issue has been reported multiple times by other Users with the PR4's while others (like myself) have no problems at all and love the tires. Is there a QC problem during manufacturing?

 

2) Tire scuffing is another issue reported and there seems to be a lean towards increasing front tire pressure to 38~40PSi, which as reported seems to highly reduce/eliminate scuffing.

 

[Guest Kakugo]

Cheers Albert.

I will contact Michelin and hear what they have to say.

[Scubadvr]

You could also check to see that it is mounted in the correct direction.

[Matts_12GS]

Check the amount of damping in ESA, maybe try to run it one setting higher than you need (e.g. 2 helmets instead of just one) and see if that changes the feeling.

[EffBee]

Your location says "Middle of the Alps." At what altitude? You may be setting it correctly for where you live, but do you ride at higher or lower altitudes? If lower, you're probably riding on overinflated tires. Here's a quick chart to show atmospheric pressure at increasing altitudes. Not that you get about a 10% drop for every 3000 feet.

 

Alt (ft)..........Atmospheric Pressure (psi)

Sea Level.......14.7

1,000............14.2

2,000............13.7

3,000............13.2

4,000............12.7

5,000............12.2

6,000............11.7

7,000............11.3

8,000............10.9

9,000............10.5

10,000...........10.1

 

[Guest Kakugo]

Thanks, useful info.

However the issue seems to be much more tarmac than height related.

I suspect it may be something to do with the ply: perhaps it's so much stiffer than the one used on the PR3's I was accustomed to they seem to bounce a lot?

Perhaps I need to lower the pressure?

 

It's time to contact Michelin now, hoping they don't answer "Check your tyre pressure".

 

 

[kgerry]

+1 on making sure the direction arrows are facing the right way...

[lkraus]

Well, we don't seem to be making progress by discussing air pressure. I'm not seeing any data on how you ruled out possible effects from the "freshly rebuilt" ESA shock. Let's kick around "how many helmets" and "sport", "comfort" etc. Was the rebuild done at the same time as the tire change? Was the spring replaced?

[Guest Kakugo]

Well, we don't seem to be making progress by discussing air pressure. I'm not seeing any data on how you ruled out possible effects from the "freshly rebuilt" ESA shock. Let's kick around "how many helmets" and "sport", "comfort" etc. Was the rebuild done at the same time as the tire change? Was the spring replaced?

 

We are not making any progresses for two reasons.

 

First, it seems the Michelin customer service here is unreachable, for whatever reason. Tried three times today and no luck.

 

Second, I haven't ridden the bike since and, in spite of not being exactly 100% on these tyres and having the service reminder lit (long story but do not worry), a friend managed to talk me over to go to Spain next week.

 

The shock (or to be more precise, both shocks) was rebuilt in February already. No spring change, no nothing apart fresh oil, nitrogen and an inspection. ESA is always set in single rider mode and normal mode.

 

I was perusing a few other boards and, as Albert suggested, it seems I am not the only one to have noticed these tyres are much harsher and less smooth than PR3's. That would be a much better definition of the issues I am having than simply "bouncing around".

Don't know if it's a batch of tyres or the riders, but I am not alone.

Some people had luck dropping the pressure to 2.2/2.5 bar, others just cannot get along with them.

I am going to experiment with pressure as soon as I have half an hour to ride the bike, then be back to you.

 

[Dennis Andress]

We have the PR4 GT tires on both our bikes. "Harsher" is about my impression of them. We don't have any complaints, but I next time I'll get the plain version and not the GT.

[Guest Kakugo]

We have the PR4 GT tires on both our bikes. "Harsher" is about my impression of them. We don't have any complaints, but I next time I'll get the plain version and not the GT.

 

Very curious to hear from you, since you are likely to change tyres before me.

 

In the meantime, as Michelin Customer Care appears to have gone AWOL, I decided to carry out a zero cost experiment and let a tiny amount of air out of the tyres. There was already a marked improvement.

I plan to attempt running the tyres first at 36/42psi sharp and then, if still not satisfied, at 2.4/2.8 bar first and then at 2.2/2.5 bar.

 

From what I could make out, these tyres are even more sensitive to pressure than PR3's. I may have let out 0.05 bar of pressure and I already feel a difference.

 

Very confused...

 

 

[Mr. Frank]

Motorcycle Consumer News just tested the new BMW R12RT. They mentioned they did not like the new Pilot Road4GT. They complained of heavy turning and vagueness in mid curve. The stiffness of the GT may be a problem when riding one up.

[BrianT]

My favorite tire has been the PR3's for traction vs mileage. I was eager to try the new PR4's. I have less than 1k miles on them now, but they do feel stiffer or less forgiving on the bumps. Might be the harder compound vs the PR3's. On the rear, they switched from medium center and soft shoulder compounds to hard center and medium shoulder compounds. One of the reviews I read described it as, "the GT rear tire casing features Michelin 2AT (Dual Angle Technology) that employs a combination of bias and radial construction, which results in a claimed 15-percent increase in rigidity."

[Mr. Frank]

One of the big pluses of the Pilot Road series has been the compliant ride. I'm due for tires soon and will be staying with the PR3.

[Lemans]

I replaced a PR3 B with a PR4 GT on my K1300GT, both using the stiffer sidewall. Not sure of the weight difference between an GT and an RT, but I suspect it is more than 70 lbs. After 2000 miles, all in the dry, at least half in the twisties or high-speed sweepers, I have no complaints. Turn-in and ride quality seem unchanged from the PR3 B. I don't notice the "pointy" profile described by another poster. I'm curious what tire the O.P. was running prior to the PR4.

[Guest Kakugo]

I think we finally might be getting somewhere.

 

After dropping the pressure exactly (I have a pressure gauge that's accurate to the second decimal and carries out "on the go" unit conversion) to 36/42 psi, and not a tiny bit more, this morning I went for a 20 miles ride.

The tyres feel so much better: still a bit harsher than PR3's but a far cry from a week ago.

 

I've always maintained PR3's were the most pressure-sensitive tyres I've ever had (a 0.05 bar pressure drop could be easily noticed, especially at the rear) but these tyres are even more ridiculous. It seems absurd such a minute drop in pressure can make so much difference...

 

The rear tyre has a much sharper profile than both PR2's and PR3's: this morning I had the occasion to park my bike near an RT with brand new PR2's and the difference was staggering. The PR4GT rear is so pointy it almost looks like a 160 width by comparison.

 

We'll see how things evolve: next Saturday I am leaving for Spain and I'll be having plenty of occasions to try these tyres out on a long run.

[Glenn Reed]

Glad to hear things are getting better for you, enjoy your trip to Spain!

[Guest Kakugo]

Glad to hear things are getting better for you, enjoy your trip to Spain!

 

Thanks.

[lkraus]

No help with your problem, but still interesting PR4 info here: http://cyclenews.uberflip.com/i/319200/76

[Guest Kakugo]

Back from a few days riding a lot of magnificent (and a few dreadful) roads in France a few outstanding roads in Spain.

 

What can I say about PR4's? It's all about the pressure!

Before leaving I dropped tyre pressure to 2.45 bar front and 2.85 bar rear, and there they stayed the whole trip.

 

I met the most wide range of conditions: a dreadful detour in cold pouring rain in Provence, the amazing Gorges d'Ardeche in sunny and very warm weather, a very heavy downpour near Gap, lots of highway miles with a strong crosswind in Roussilon and the jaw dropping Col de Boixols in perfect riding weather.

 

How did the PR4's behave? Nothing short of magnificent. It's unbelievable (and I am not using this word lightly) how such a measly 0.05 bar pressure drop can work wonders.

 

So, if you plan fitting PR4GT's or have already done it, drop the pressure a tiny bit. That will solve if not all at very least 90% of your problems and you will enjoy the massive step forward from the already excellent PR3's.

[Blind Squirrel]

Thanks!

 

"tyre pressure to 2.45 bar front and 2.85 bar rear" = 35.5 PSI and 41.3 PSI. This confirms what I believe most people recommend 36/42 PSI on them. I am looking at PR4s as one of the contenders for my next set of tires.

[Lester V]

I think we finally might be getting somewhere.

 

After dropping the pressure exactly (I have a pressure gauge that's accurate to the second decimal and carries out "on the go" unit conversion) to 36/42 psi, and not a tiny bit more, this morning I went for a 20 miles ride.

The tyres feel so much better: still a bit harsher than PR3's but a far cry from a week ago.

 

I've always maintained PR3's were the most pressure-sensitive tyres I've ever had (a 0.05 bar pressure drop could be easily noticed, especially at the rear) but these tyres are even more ridiculous. It seems absurd such a minute drop in pressure can make so much difference...

 

The rear tyre has a much sharper profile than both PR2's and PR3's: this morning I had the occasion to park my bike near an RT with brand new PR2's and the difference was staggering. The PR4GT rear is so pointy it almost looks like a 160 width by comparison.

 

We'll see how things evolve: next Saturday I am leaving for Spain and I'll be having plenty of occasions to try these tyres out on a long run.

 

I just happened to have a new rear PR3, Metzler SportecM3 and a PR4 GT unmounted in my shop. All the same size 180/55/17

 

The PR4 is slightly wider than the PR3 and has less of a sharpe profile than the PR3. (PR4 is not pointy at all). The Metlzler is taller than both by about 1/2 " and has a much more defined peak or sharp profile than both of the Michelins. Both Michelins were made in February of 2014.