SV650SK6 tyres - trying PR4 instead of Z8s

[aesmith]

Hi,

When I first needed tyres for the SV I went for Metzler Z8s. I'd had good experience with earlier Metzlers on the CBR, for example I could run them right down to the legal limit without handling issues. By contrast the Michelin's that were on the bike wore out really quick and also flattened off quickly.

A year and a bit on, the Metzlers were due for replacement. My experience was mixed.

On the good side the rear lasted 15 months (say 13,000). On the bad side I was never really happy with wet grip at the rear, even from new. I would get the odd rear wheel slither exiting a wet roundabout if I opened up the power too quickly, and even a couple of times had wheelspin when accelerating from say 50mph in a straight line (wet again, of course).

The front I kind of screwed up, it lasted 12 months (say 11,000) but I messed around with tyre pressures as the bike felt much better with a softer front. I over did it and ended with uneven wear. Taking more care they should have lasted longer.

The other reason for chooing Metzler was that I'd missed the fact that Michelin Pilot Road are a different animal from the Pilot Power that had worn out so quickly.

So I've just fitted a pair of PR4s based on all the recommendations here, and will see how I get on and how long they last.

Tony S

[jambo]

You're not alone, I suspect you'll get on fine with them, there's a thread in the tyre section here (http://forums.sv650.org/showthread.php?t=207475) with people's experiences thus far, most of which seem positive.

Jambo

[aesmith]

Yes, they seem to be pretty much universally liked on here. What surprised me was the price was almost exactly the same as the Z8s, I was expecting them to be more expensive. Looking forward to seeing how well the bike runs on the PR4s, I've only done 30 damp miles so far.

I still feel I didn't give that Metzler front a proper chance, but once it was worn uneven it started to feel really weird so would have had to go even if it wasn't at the legal limit at MOT time.

[NTECUK]

Your not alone with the Z8 spinning

Mines done 1000 miles and is not really in the same univers as the M5 i had previously.

[aesmith]

After a bit over a year I've had to change the front, but the rear still has quite a bit of life. That's interesting because with previous bikes the rear has always worn out first.

[Swin]

Replaced my PR2s a few weeks back, went for the PR4s and they are doing superb at the moment - probably about 500 miles so far and they are even better than the PR2s, which were very very good in any case

[Sentinel]

After a bit over a year I've had to change the front, but the rear still has quite a bit of life. That's interesting because with previous bikes the rear has always worn out first.
Sounds like a problem with your bike and or tire pressure.

[Daywalker]

Just put some pr4s on my curvy k2 and what a difference they've made especially in the wet/sleet & hail yesterday (sat) i'm using the standard tyre pressures 33f & 36r and she feels well planted on the road, miles so far about 400 & well pleased with the hoops :smt023

[Bibio]

PR4's are superb but not s good in the wet as the PR3's which are just stupidly good. PR4's seem a bit better in the dry though.

aesmith, if you feel you need to drop the pressure on the front to gain grip then i would suggest you look at your suspension. or you weigh 8st. there should be no need to drop the pressures.

[Sir Trev]

After a bit over a year I've had to change the front, but the rear still has quite a bit of life. That's interesting because with previous bikes the rear has always worn out first.

Oddly (I think) new fronts come with less tread when new than rears. I have a tread gauge and measured my PR3s after they were fitted. More likely the pair will wear out at the same time possibly.

[Sentinel]

Just put some pr4s on my curvy k2 and what a difference they've made especially in the wet/sleet & hail yesterday (sat) i'm using the standard tyre pressures 33f & 36r and she feels well planted on the road, miles so far about 400 & well pleased with the hoops :smt023
How do you find out what the "standard" pressures are for tires? I think I've only seen the Max Cold numbers.

[DomP]

I've got a pr4 on the front which was vastly better than the massively worn out original tyre. Can't wait for the rear to wear out now to match it up.

[aesmith]

aesmith, if you feel you need to drop the pressure on the front to gain grip then i would suggest you look at your suspension. or you weigh 8st. there should be no need to drop the pressures.
That was with the Metzlers. The Michelins have always been 32/36. But yes, improved front suspension would be good. I have the emulators, but not really had a time when I felt like taking the bike off the road long enough to dismantle forks and send the rod to be modified.

By the way, looking at the spec it seems the rear is dual compound, but not the front. That could be why the front wears quicker. I also noticed the bike feeling a little "uneasy" towards the end, nothing serious but noticeable compared to the feel with a new tyre.

Anyway there's still some meat in the rear and it still feels fine so we'll see how long it lasts.

[Bibio]

the PR4 fronts are dual compound. excess wear on the front just tells me that the front suspension is needing attention. i get between 7-9k from a front but i'm a fairly aggressive rider.

[aesmith]

Cheers, I never really made the link between suspension quality and tyre life, but it makes sense. Anything I can do to improve tyre life is a bonus.

[Bibio]

if suspension is too stiff then the tyre carcass flexes too much (something has to give).
if suspension is too soft the wheel 'patters'.
in both cases it accelerates wear. yes a tyres carcass should flex under normal conditions so it creates a wider footprint but should only be under certain conditions like cornering. setting tyre pressures properly allow the carcass to flex properly. too high a pressure and it wont flex enough creating wear. too low a pressure lets it flex too much again creating wear. your hot pressures should be around 10% of your cold for correct pressure (thank Luckypants for finding that out).