Front Tire Wear

[lhanscom]

Every front tire I've owned, on both my 700, and now my 1150 has cupped. What does this mean? I figured I needed to do suspension work to the 700, and that's why that bike was doing it, but the same thing has happened with the 1150 now. So, is this just how tires wear, or is it something in my riding style? I put on 100miles a day, over various conditions, from highway to rough pavement. I like riding the corners hard, but don't do it all the time either. Speeds from 40 to 80. I've run metzlers, Kenda's, Cheng Shins, and currently have a Dunlop on.
Thanks for any input.

[Hoomgar]

I have seen this on bikes where the rider is really big and fat.


















:twisted:


LOL!!!

OK, jab in the ribs out of the way, I would say since you have the same issue with two different bikes Luke that it would be because of how you run it up into the corners. Do you break late and hard a lot of the time? Because this will do it.

Other than that it must be the same gremlins chewing away at your tire in your barn while you sleep.

[lhanscom]

Never thought of the gremlin thing. From your first comment I deduce that you have the same issue? :P

(Right back at you big guy)



Oh, and yes, I tend to late brake some, I guess that's at least part of the problem, though I didn't think I was being that hard on things.

[Hoomgar]

Never thought of the gremlin thing. From your first comment I deduce that you have the same issue? :P

(Right back at you big guy)



Oh, and yes, I tend to late brake some, I guess that's at least part of the problem, though I didn't think I was being that hard on things.

Well that's what I was wondering because I would say I tend to be a bit hard on the old front brakes myself but the difference may be that I brake earlier than later. I am usually almost completely done braking by the time I start to lean her over. Usually just a little feathering off of the front brake as I start to lean and then some acceleration as I make the turn. Even when I am running hot.

You may be simply pushing enough harder that you are braking just enough later than I do that it is hammering your side treads and cupping them.

This is all speculation but I am at a loss as to what else it could be.
It doesn't happen to me on any bike with any tire and I am shaped very much as you are so the first theory is not only a joke but could hold some weight (no pun intended) as us heavier guys when braking late could pound our tires a lot harder.


Tubby

[Bolder Biker]

Just quickly dug these up off the internet:

All tires are subjected to uneven wear from bumps. Car tires show it less
because they are wider and there are four of them. Car tires are often
rotated, which changes the cupping and basically negates it.

Bike tires cup because of the 'pogo' effect of the suspension. With only
one wheel on each end, you can't rotate the tires. MC tires a quite a bit
softer than car tires and as such are more subject to uneven
wear. Motorcycle tires are also subject to a hell of a lot more stress
than a car tire.

Preventing cupping includes keeping the tires well inflated and buying
harder tires.

I am not an expert - these are just my notes from the last time this came
around.

Will
http://will.mylanders.com/outdoors/m...ad.pl?file=122


How can I keep my tires from cupping?



You may not be able to entirely avoid cupping. Tire cupping or irregular wear is a somewhat common occurrence on all vehicles. On a four-wheel vehicle, you are advised to rotate your tires periodically to even out wear. Unfortunately, you do not have this luxury with a motorcycle because front and rear tires, unlike those on a four-wheel vehicle, are not interchangeable.

However, there are steps that can be taken to minimize cupping and uneven wear on a motorcycle:
1. Maintain your motorcycle and particularly your front forks and suspension.
2. Avoid hard braking whenever possible. Braking causes the tire to grab and wear in one direction. When braking is applied to the front tire, the load transfer over-flexes the tire and increases the tendency for cupping and uneven wear.
3. Maintain your tire pressures. Underinflation or overinflation in motorcycle tires are significant causes of cupping and uneven wear, particularly in association with hard braking and/or trailer use.

Some of today's tires feature tread patterns and constructions that are less prone to cupping than the ribbed tires of old. The Dunlop 491, D401 and D402 touring and sport touring tires are good examples.

Tire companies can, and are, helping to minimize cupping and uneven wear but you, the rider, must do your part. Follow the aforementioned guidelines. How Much Run-in Should I Give a New Tire? When new tires are fitted, they should not be subjected to maximum power or hard cornering until a reasonable run-in distance of approximately 100 miles has been achieved......


BB

[lhanscom]

Very good info, thanks a lot.

[Joe Nardy]

I learned in a previous life, while working at a tire store, that cupping occurs naturally on the front tires of vehicles due to the fact that they only 'pull' in one rotational direction. Rear tires are subject to acceleration, braking, and engine braking forces which tend to even out the tread wear. Front tires freewheel most of the time with little force acting on them. The only real force is braking force, which is always in the same direction. This causes the cupping. It is also seen on vehicles such as pickup trucks (2 wheel drive) which have large tires with aggressive treads. It does not occur to any noticeable degree on full time four wheel drive vehicles, which have opposite acceleration and braking forces. In the cage world cupping is referred to as 'free wheeling wear' because it only occurs on tires with no drive forces (free wheeling).

Joe

[oldschoolGS]

Normal on every front I have ever run - when it gets very pronounced buy a new tire. I have yet to fully wear out a cycle tire before it gets replaced. Cheap insurance against bone breakage I guess. Ride On, Ed.
1983 GS750ED
2001 TL1000S (for sale)

[SqDancerLynn1]

What kind of air pressure are you running?? front should be around
35 psi for good wear Road conditions can also have an effect on tire wear

[saaz]

Some tyres are more prone than others to cupping. Also, if the tyre is not up to the weight of the bike it can flex too much. If the damping and spring rates are not right the tyre has to make up for this, which can lead to cupping. There are so many factors at play that it is hard to say.

[Hoomgar]

You know the tire pressure thing may be onto something there Luke.
I have never had any cupping on any of my motorcycle tires but have had it on front truck tires as stated above. In the cases where I got it they were always tires with aggressive tread patterns that ran lower pressures. On tires with higher pressures I would have to say I don't see it as much.

On my motorcycles I always have run the higher end of the allowable pressure scales and maybe that is why I don't see it? Do you run slightly lower pressures maybe?

Also terrain was mentioned, maybe something with the roads in your area? Or the combination of these two things?

[mdole]

I have had cupping problems with several bikes. The Dunlop F-11's were the worst tires I have run for cupping. I tend to run the max inflation pressure in my tires and that helps slow the process.

Most of my riding is on two lane roads that are not always in the best condition, I tend to ride fast when commuting before traffic hits, and the roads have lots of curves. I believe that all of these things contribute to the problem.

I tried using different tires and got an improvement with a Metzler 880 on the front, then I ran a Kings front and it did even better as far as wearing out before it was cupped too bad but it only went 6k miles. I am now running a Dunlop Elite II on the front and it hasn't had any noticeable cupping in the last 10k miles.

Mike

[lhanscom]

Thanks for all the great info, I need to check my psi, I normally run max psi, but I haven't checked it in a while, so maybe it's lower then it should be.

[Guder]

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

[mdole]

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