Tyre Pressure PR4

[raj_27]

Hi Guys,

I just have a set of new PR4s fitted. Just wondering what kind of pressures do you guys run? The bike specifies 33 front 36 rear. When i checked the pressures on Michelin website for the PR4s the specify 36 front and 42 rear. All pressure in PSI.

 

[Erci]

Hi Guys,

I just have a set of new PR4s fitted. Just wondering what kind of pressures do you guys run? The bike specifies 33 front 36 rear. When i checked the pressures on Michelin website for the PR4s the specify 36 front and 42 rear. All pressure in PSI.

36/42 is recommended for riders over 200 pounds. Anything under (including cargo weight).. manual says 33/36 and it works well for street riding.

 

[iviyth0s]

I think I run 38/38 myself (154lbs) on my BT-023s

 

[tejkowskit]

170lb and running 33/36 with my pr4's. It feels fine. I bump it up a few psi if I'm touring and am loaded with gear.

 

[SweaterDude]

for highway/distance riding add a few PSI, but otherwise its better to run to spec. for better grip. your wear and mileage wont suffer if youre hitting the backroads.

 

[PhotoAl]

Seems like a couple of years ago everyone went to 36 and 42 for tire pressures. That is why you are seeing that on Michelin's web site. My 2012 CBR600RR has 36 & 42! I'm running PR3's but generally run them at 30 to 32 on the front and 36 on the rear - may be too much for really fast riding. When I'm headed out for a long trip I put them at 36 and 42. Have to remember where they are as it does affect the handling.

 

[raj_27]

I was just running bike specific pressures (33-36) always no matter what tires. Until yesterday the guy who installing the Tyre said that Michelin's are different than the stock dunlop (something to do with dunlop having steel reinforcemnt and michelin not) and require different pressures. But he also said it can vary and everyone likes their own combinations. Hi recommendation was 36-38.

I am going to give it a try with that and see how I go, but i am pretty sure i am not experienced enough to tell the different feel with different pressures.At least with my type of riding (commuting).

 

[shannim]

My understanding is that the recommended pressures in the manual are for the OEM tires. I run PR3s around 40/40. This gives me the best handling, in my opinion. And I'm a small/light guy. 5'6", 130lbs without gear.

 

[Erci]

My understanding is that the recommended pressures in the manual are for the OEM tires. I run PR3s around 40/40. This gives me the best handling, in my opinion. And I'm a small/light guy. 5'6", 130lbs without gear.

Wow.. that's seriously high. Think about what happens to your traction patches when you put that much air in. There is less tire touching the ground, at any given point. When you go to brake hard and the weight transfers forward, you want the tire patch to grow. With so much pressure up front, you are definitely minimizing this effect.. and therefore are potentially more likely to lock the front wheel under hard braking.

You also want the tire pressure to come up as you ride.. as in: warming up the tires. Overinflation will prevent your tires from warming up, because traction patches are too small. So potentially, your tires are *cold* the whole ride.. once again, less traction.

I agree that rolling profiles of motorcycle tires can be drastically different, but that much of a pressure difference seems exsessive.

Also consider this: I know we are talking about street riding, but baseline pressure on the track is 30psi front/rear.. for bikes where manufacturers recommend 36f/42r. Of course it's about maximum traction on the track and not about tire wear, but there needs to be a compromise.

For what it's worth, I had PR2 on both FZ6 and FZ1 (I know.. not exactly the same as PR4) and I always ran suggested pressure (33/36 .. I weigh 170). Bike handled beautifully.
Also ran suggested pressure on FZ1 with those tires (36/42) and they lasted over 12k miles.

 

[shannim]

Wow.. that's seriously high. Think about what happens to your traction patches when you put that much air in. There is less tire touching the ground, at any given point. When you go to brake hard and the weight transfers forward, you want the tire patch to grow. With so much pressure up front, you are definitely minimizing this effect.. and therefore are potentially more likely to lock the front wheel under hard braking.

You also want the tire pressure to come up as you ride.. as in: warming up the tires. Overinflation will prevent your tires from warming up, because traction patches are too small. So potentially, your tires are *cold* the whole ride.. once again, less traction.

I agree that rolling profiles of motorcycle tires can be drastically different, but that much of a pressure difference seems exsessive.

Also consider this: I know we are talking about street riding, but baseline pressure on the track is 30psi front/rear.. for bikes where manufacturers recommend 36f/42r. Of course it's about maximum traction on the track and not about tire wear, but there needs to be a compromise.

For what it's worth, I had PR2 on both FZ6 and FZ1 (I know.. not exactly the same as PR4) and I always ran suggested pressure (33/36 .. I weigh 170). Bike handled beautifully.
Also ran suggested pressure on FZ1 with those tires (36/42) and they lasted over 12k miles.

All valid points. I just find the bike handles much better at that higher pressure. The bike goes exactly where I point it more predictably and the turn in is very precise, as if it were on rails. At lower pressures it feels less planted to me. And I don't really notice any difference in braking, but then again, most of my riding is on a highway with very little traffic. When I did my track day, I definitely ran lower pressures to account for the heat.

 

[OneCheekRider]

Overinflation will prevent your tires from warming up, because traction patches are too small. So potentially, your tires are *cold* the whole ride.. once again, less traction.

I just want to clarify that over-inflation leaves the tire carcass 'cold' while the surface of the tire can actually overheat. At street speeds this might not be so noticeable, but agreed that traction is definitely compromised and tire wear can still be affected. Interesting read on (track) tire wear here: Race Track Motorcycle Tyre Wear Guide - Types and Causes - some of which can be applied to the street.

Personally, I wouldn't run a front tire on an FZ6 (and most bikes) greater than 36psi (cold) due to the sole fact it can take 100% of my braking power and I want all the traction I can get since it's a lot harder to control a front wheel slide, especially in an emergency braking situation. Since fronts typically cost less and last longer than rears, why not go for more traction? For street riding, I use 33/38.

 

[Erci]

I just want to clarify that over-inflation leaves the tire carcass 'cold' while the surface of the tire can actually overheat. At street speeds this might not be so noticeable, but agreed that traction is definitely compromised and tire wear can still be affected. Interesting read on (track) tire wear here: Race Track Motorcycle Tyre Wear Guide - Types and Causes - some of which can be applied to the street.

Personally, I wouldn't run a front tire on an FZ6 (and most bikes) greater than 36psi (cold) due to the sole fact it can take 100% of my braking power and I want all the traction I can get since it's a lot harder to control a front wheel slide, especially in an emergency braking situation. Since fronts typically cost less and last longer than rears, why not go for more traction? For street riding, I use 33/38.

+1. Yeah.. didn't want to go into too much detail. Not very likely to get a cold tear on the street (overinflation = hot surface + cold carcass.. ugly ugly tire wear on the track).

 

[Marthy]

I found some info on website a while ago. 10% front & 20% rear pressure raise from cold to hot was the guidelines. Coming from a racecar back ground, make sense to me.

Sent from my SAMSUNG-SGH-I337 using Tapatalk