Front Tire Wear

[Hoomgar]

I normally run max psi,

If you are referring to the max pressure listed on the sidewall, you are probably running too high, which is more likely to pronounce uneven wear on a motorcycle than running too low.

You should inflate your tires to the maximum limit expressed by the vehicle manufacturer for your particular application (by vehicle, passenger, luggage, etc.) for the best wear and fuel economy.

The max rating on the tire is simply a physical limit of the construction and is not intended as a usage guideline.

Guder

I think that your inflation pressure needs to be set by the type of riding you're doing.

I was running the sides of my tires until I started running near the max inflation pressure for the tires. I do most of my riding on two lane mountain roads and ride moderately aggressive so that seems to leave tires with good center tread and two bare strips around the sides at much less mileage than inflating them more and getting some of the wear in the center of the tread,

Mike

Same here Mike and I also go a few over max PSI in some cases as needed. It's not an absolute value and is conservative. I do know that I got cupping with lower pressures on trucks and it stopped when I used higher pressures and that my bikes always run high pressure and have never cupped so that has to tell us something Guder. I believe you in that to some degree but I think my experiences have been pointing to the opposite of that. It's still no absolute though and I don't claim to be an expert on this subject by any means.

[Bolder Biker]

I have never experienced any cupping on the ME33 Laser front tires that I have run for years on my 1983 GS750ES......but then I try to ride as smoothly (if rapidly) as possible through the canyon twisties. I must admit that I don't do a lot of hard braking as I try to carry as much speed as I can through the corners, while still being prepared for the unexpected on the many blind bends.

What I have found interesting relates to front tire pressures. My GS's owner's manual calls for front/rear inflation pressures of 28/36 psi for solo, and 32/40 psi for two-up. When I recently replaced my last Metzeler ME33 with the newly-designed ME330 I downloaded a Metzeler PDF for tire applications. This recommended a minimum front pressure of 34 psi for the ME330 for my GS model (i.e. 6 psi higher than the 28 originally recommended in the bike's manual for solo riding). So, I am now compromising on a 35 psi pressure for my riding (mostly two-up), with the thought that I may have to raise the pressure even higher to 36 or 37 psi when carrying a passenger.

BB

[snowbeard]

hey guys,
I've been meaning to ask about this, at least this may be what I wanted to ask... I've got the ME77 perfect on front, and lately I've noticed that each knob of the tread has "cupped" or is uneven in height from front to back. it definitely comes from braking in my case because the knobs are shorter in the front (at least it's the front where it contacts the road), kind of curving up to the back, as if it had been sliding. kinda how cheese on a cheese grater gets balled up at the back... what I'm starting to wonder is can I turn this tire around and run it backward? I have yet to find a direction arrow on it, and the pattern of the tread is symmetrical such that it would have been the same in either direction once upon a time.


I know, just go get a new tire, huh?

[Guder]

I am certainly no expert in motorcycle tires, either. I would also stick with whatever combination of tire/load/pressure you have safely used for best tire life.

Anecdotal evidence can be confusing due to the number of variables involved, and the length of time it takes to cycle through a new tire for comparison. All the disclaimer mumbo-jumbo being said...

I work in the US warranty center for one of the major manufacturers, albeit commercial tires, not motorcycles. Speaking generally about tread wear, the low spots you see on a cupped tire are the areas which show the least pressure on the footprint. Carrying a pillion will actually increase the life of a rear tire. Pressure on a tire is a result of load and inflation. The greater the load, the greater the required inflation. Changing that formula, greater inflation with the same load effects less footprint pressure, hence faster wear.

That being said, I also tend to go a few pounds higher than the vehicle recommendation on my tire pressure for various reasons.

Presented merely for academic interest. YMMV.

Guder

[Hoomgar]

hey guys,
I've been meaning to ask about this, at least this may be what I wanted to ask... I've got the ME77 perfect on front, and lately I've noticed that each knob of the tread has "cupped" or is uneven in height from front to back. it definitely comes from braking in my case because the knobs are shorter in the front (at least it's the front where it contacts the road), kind of curving up to the back, as if it had been sliding. kinda how cheese on a cheese grater gets balled up at the back... what I'm starting to wonder is can I turn this tire around and run it backward? I have yet to find a direction arrow on it, and the pattern of the tread is symmetrical such that it would have been the same in either direction once upon a time.


I know, just go get a new tire, huh?

The tire is positively directional and no you do not want to turn it around.
In most cases I would say don't worry about it unless the cupping is severe.

[snowbeard]

that's what I figured, thanks! no real problems so far, I'll have to see if the new one makes any noticable difference when I decide I need it!!

[Anonymous]

I have heard for years that cupping results from tires that are out of balance and will be worse if the suspension is not working well, i.e., by allowing the wheel to hop. I don't recall ever having this problem on any of my motorcycles.

[Carter Turk]

cupping tires

120/80/16's on both bikes? I think that helps contribute to the problem. They always feel like they're pushing and going to tuck under. Also that big area of unused rubber on the edge where it drops off like a cliff. It seems those fronts have a narrow contact patch when leaned over contributing to wear in one area regardless of tire pressure. Carter

[oldschoolGS]

You are probably right- the problem could be more noticable on the 16in fronts. I have seen it on the Dunlop K591 and Metzeler ME33 fronts that I have run. I always use correct pressure, proper balance and have the front suspension set up stiff. I am very hard on tires though and replace them often. Ride Safe, Ed.

[Sandy]

You're right about the cupping on K591's. Ran the K591R's on my FZ750 street/race bike. Was really hard on the tires, trail braking, track use, extreme cornering loads, etc. They cupped badly and when they got really bad replaced them. The air pressure and balancing were always correct and the tires worked perfectly well until the tread got scarce where they were cupped. Always stuck like crazy and were very predicatable when driven at their adhesion limit. Thank God I don't do that anymore!!!

[oldschoolGS]

The softer compounds might also be more prone to this. I have always used the R compound on the 591's and the CompK ME33. That original FZ750 was a really nice bike- I remember racing a few of them in the late 80's- it was pretty fast back then. Ride On, Ed.
1983 GS750ED
2001 TL1000S (for sale)