Michelin Pilot Road 3 tyres progress report

This post is predominantly for my mate Jules in Australia.  He's been nudging me along to write a progress report on how the PR3's are going on the Street Triple.  Personally, I think he simply wants to sit back and watch the fur fly as everyone seems to hold strong opinions about tyres, even if there's bugger-all objective evidence for aforesaid opinions!  The report is a bit nerdish (oh all right, anal!) so if you want to do something exciting like watching paint dry, it's ok by me :-)!  Think yourself lucky - Jennie has to put up with this sort of behaviour all the time!

Background
Just to recap, I'm an Avon fan, having had them on my Blackbird and then the Street Triple.  I fitted them to the ST after being a little disappointed with the Dunlop Qualifier sport OEM tyres.  The Qualifiers gripped ok in the warmer weather, I was nervous about them in cooler, wet conditions and they also tended to tip into a bend rather than roll in smoothly.  By 6000 km, they had lost most of their tread and also lost their shape.  The replacement Avon Storm 2 sport-touring tyres did most things really well but were outstanding in the wet, which was not unexpected based on past experience. They were replaced at 10,000 km which was satisfactory, given that the ST gets used for its intended purpose although the front tyre triangulated a bit towards the end of its life.  I would have happily used them again except that the NZ Avon importers had hiked the price significantly beyond that of competing brands.  That was the spur to look around and the PR3's sport touring tyres were chosen.  Photos of the Storms and PR3's when first fitted, together with some accompanying remarks can be found HERE.

The PR3's have now been on for nearly 6 months, so how have they gone so far?  Before we get to that, let's have a think as to why opinions on tyres vary so much (a euphemism for unadulterated bullshit in most instances) .  There are many variables which impact significantly on tyre performance (road surface and temperature, ratio of straights to curves, tyre pressures, bike weight and geometry, riding style to name but a few. Bike magazines which test normal road tyres round a test track for lap times don't replicate real world conditions either.  In other words, we're not comparing apples with apples in most cases. I'm not going to offer up much in the way of hard science either BUT what is relevant is that the ST has been ridden by me over virtually identical road and weather conditions for a touch over 20,000 km using 3 different sets of tyres.  At least this gives strong comparative indications, if not absolute ones.

First Impressions
The PR3 is similar to many modern road tyres in that it has dual compound construction - harder towards the centre to reduce wear when vertical and softer towards the edges for additional mechanical grip when leaned over.  I have the higher load rating "B" specification on the rear.  Carcass construction allegedly also increases the contact patch area when leaned over but other manufacturers make that claim too.  Where the PR3 is significantly different is in the tread pattern.  Michelin claim that they are the first to use the fine grooves (called sipes) which are a feature of some performance car tyres for clearing water at a higher rate than conventional rain grooves.  Here's a picture of the front tyre when it was first fitted:

Pilot Road 3 front - brand new

After leaving the tyre fitting place, my first noticeable impression was at walking pace coming up to the first set of traffic lights. There appeared to be a slight vibration through the bars at around 5-10 km/hr.  I actually wondered whether the transverse sipes were creating a harmonic at low speed. It wasn't enough to be worrying and it now seems to have gone away.  Don't think I was imagining it!  After taking it easy for 50 km or so, I started to explore the characteristics a bit more.  Turn-in was similar to the Avons, in that it's a progressive roll rather than the more pronounced drop in of the Dunlop Qualifier.  The reason may be due to a less crowned profile.  I'm also of the view that the PR3 is fractionally slower steering than the Avon Storm 2, but not to the extent that it's an issue and feel perfectly at home on them. In fact, they were so reassuring that there were no chicken strips on the rear tyre at the end of the 160km trip home.

Experience to date
The tyres are just coming up to 7000km from new.  Three characteristics are immediately noticeable.

• The profile is perfectly even with little or no hint of squaring off  on either tyre or "triangulation" on the front.  

• There is heaps of tread left.  I regret not measuring the tread depth when new but there is still over 3mm in the centre of the rear hoop  which suggests that 12000 km + will be easily attainable, even riding with enthusiasm.

I set the tyre pressures with a quality digital gauge (NEVER with a gas station inflator) and run them at 35-36 psi front and 39-40 psi rear, a little lower than in the Triumph manual.

Here are photos taken today, showing the tread and even wear profile.

Front

Rear

Front - worn nearly round to the edge and minimal tearing

As mentioned earlier, the PR3's were chosen over the Avons principally on price - NZ$600 fitted and balanced against $NZ650.  If you factor in the clearly superior tyre life, then it makes the PR3's a really attractive economic proposition.

• The third characteristic is performance.  In the dry, they really grip.  Job to say whether they're any better than the Avons because my mental bar is set lower than the limits of either brand of tyre but suffice to say, they're confidence-inspiring.  However, in wet conditions, they're sensational.  I thought Avon were great (and they are) but the PR3's are better.  In my last post on riding Dr Andy West's Daytona 675, he enthused about their performance in the wet and has subsequently said that when the Supercorsas are worn out, he'll be replacing them with PR3's.  Clearly, the Supercorsas are a superior tyre for continuous high speed work such as track days but for everyday road use where they don't reach the high operating temperatures required especially in the wet, grip is probably less than the PR3.  They certainly didn't give me much feedback in damp conditions.  Another interesting thing I noticed when Andy was riding my bike and I was following him in the wet was that the tyres were leaving a noticeable dry line behind them.  Perhaps this is an indicator of good water-pumping ability.  Must observe other bike tyres too.

Well, there we are - some impressions of the Michelin PR3 based on a comparison with other tyres fitted to the Street Triple and used in near-identical conditions - hope you think that it's been worthwhile.  More to come at life end.

Addendum:  The full end of life report can be found HERE