Ask Michelin or Ducati and they would quote their own, different, figures; for them to do otherwise would be to stray into dangerous legal territory. So where does that leave us ? Experiment between the two and try to assess what 'feels' right.
one of the guys in my other bike club is speaking directly with Michelin techs over this. Apparently they are very interested to hear this about slips / pressures, because its the first negative feedback they have received regarding PR4s. I didnt realise until I looked the other night that there are 3 different types of PR4: normal, GT, and Trail. No idea which type I have. You guys might want to check yours.
Okay, I'll risk showing my ar*e and ask the question. How do you know which are GT and which are Normal? (I presume Trail have a different tread pattern) I've PR4's fitted and it's not obvious which they are.
When my PR4 was fitted middle of May my tyre guru rang up and was told by Michelin that Multistrada 1200's should have the standard PR4 rear; so mine has that at 42psi for the rear. My PR3 rear at 42psi lasted 8600 miles and had about another 500 miles left. Took Doris on the back 2 days ago, (no panniers) and on tight bends in 5th gear and blatting along the rear was fine (tyre).
I have found the wear mark from Donington, which was a thousand miles ago nearly, hasn't yet been worn off on the rhs. Surprised it hasn't cleaned up yet
I am on my second set of PR4's - The standard PR4 Not the Trail which is for GS etc. and not the GT which is for K1600 etc. both GT and Trail are marled as such the standard PR4 just says PR4. I use 32F / 36R when solo and 34F / 38R when loaded (panniers and top box - no pillion). I have not noticed any slower turn in and not noticed any drift on acceleration out of corners and that is using all the available torque from a Ducati 1200 V twin! They just GRIP in almost any conditions you can throw at them, so far I have ridden in dry, wet, VERY wet and wet snow and they have never let go at all. Almost impossible to get the ABS or TC to kick in - they just stop the bike or make it go! On the minus side - Michelin say they will last longer than the PR3 - hmmm - not so sure about that. They can get very hot when pushed hard and the rubber feels quite soft and sticky when hot, the result is that they wear out. The 1st set had a pretty hard life - including almost 4K miles in France, Spain and Germany and after not quite 5K miles the rear was illegal, the front was OK for another 2-3K. It is noticeable that the tread pattern "feathers" on the sides on both the front and back when they are fully used. I am assuming that hard braking feathers the front and hard acceleration does the same to the rear, nothing to worry about but a bit odd, (BTW PR3's also do this), they still grip just feel rough when you touch the tyres. Current set are 2.5k old and still look OK, hopefully they will last a bit longer. My thoughts on the PR4 at the moment is that it is a great tyre for everyday use but may not be up to being ridden hard on something like a Multi, I think they get too hot and the result is accelerated tyre wear. I may try the Z8 's next time.
There's a good article perhaps you've all read on the MCN site with regard to the Multi tyres and pressures.... Staff Blog: Multistrada 1200 tyre review - MCN Staff Blogs | MCN
The set of PR4s which I fitted last week are set to the same pressures as the previous PR3s, namely 36 psi front and 36 psi rear cold for the road. I am finding that the PR4s get much hotter than the PR3s with consequent rise in pressure while running. My remote tyre pressure sensing device keeps warning me about this repeatedly, which never happened with the PR3s, and when stopping for fuel at motorways services the rear tyre feels scorching. Slightly worrying really.
Could increase the pressure a little. Mine was scorchio after taking the missus out sat but nice and warm sun on my own going a lot faster
