Front tire cupping

[The Big Red One]

It is not Busa-specific. Trust me.

This is simply the by-product of a large, heavy sport-touring bike that is using its front brake properly on the street. Virtually all front tires will cup under normal street use.

One of the biggest contributors to front tie cupping is simply the tire's tread pattern. Some tread patterns truly lend themselves to cupping, even early in it's service life - the Dunlops are among the worst of them, Q2's and RoadSmarts in particular. Some Bridgestone models also cup quite early in their life.

Other tire models don't display much cupping until close to the end of their service life. The Michelin PR2s and PR3s are examples of late-cupping tires.

I ran a set of Dunlops many many years ago that were as slippery as seal snot on an ice floe, they had so little stick they were dangerous. A friend had the same experience, so I haven't ran dunlops since, and neither has he. And after the ridiculous BT-014's and their SUPER short lifespan on my 14, plus too many other horror stories of severe very early front tire cupping with them like I had, I don't do bridgestones anymore either. I'm sure both brands make some good tires, I just prefer not to use them.
I do like conti's alot tho, very neutral and easy turning on my gen1 busa, makes it feel very nimble and predictable in the corners with lots of grip, and the road attacks still last pretty good...my fav so far for the busa. The avon storms are pretty good and PR's rock as well. Its prolly hard to go too wrong with rubber nowadays, but I doubt I'll be running dunlops or bridgestones again any time soon Once bitten twice shy I quess........

 

[Tufbusa]

It is not Busa-specific. Trust me.

This is simply the by-product of a large, heavy sport-touring bike that is using its front brake properly on the street. Virtually all front tires will cup under normal street use.

One of the biggest contributors to front tie cupping is simply the tire's tread pattern. Some tread patterns truly lend themselves to cupping, even early in it's service life - the Dunlops are among the worst of them, Q2's and RoadSmarts in particular. Some Bridgestone models also cup quite early in their life.

Other tire models don't display much cupping until close to the end of their service life. The Michelin PR2s and PR3s are examples of late-cupping tires.

Strange! I've never had a tire cup on any bike I've owned and I've owned a pile of em. But then I usually kept my suspension tuned, relaxed on the bars and checked tire pressure daily.

 

[Schism]

coincidentally, this has been bothering me within the last couple of days. these are my 1st set of Q2's and it is very noticeable compared to the bridgestones and michelin's i've ran in the past. personally, i will most likely buy another set after these burn out just because i really like the quick warm up and the confident inspiring grip it has in the corners for the street. i run 36psi front and 38psi in the rear and they still cup so i can't see the psi affecting it as much if you are running yours around 42psi which seems high.

 

[busabobh]

How, praytell, would you do that?

Alignment may not be the problem, but here is a site to show how. motocyclistonline/how to/string align motorcycle wheels.

 

[jphilipson]

It is not Busa-specific. Trust me.

This is simply the by-product of a large, heavy sport-touring bike that is using its front brake properly on the street. Virtually all front tires will cup under normal street use.

One of the biggest contributors to front tie cupping is simply the tire's tread pattern. Some tread patterns truly lend themselves to cupping, even early in it's service life - the Dunlops are among the worst of them, Q2's and RoadSmarts in particular. Some Bridgestone models also cup quite early in their life.

Other tire models don't display much cupping until close to the end of their service life. The Michelin PR2s and PR3s are examples of late-cupping tires.

+1000 on all counts. I vowed years ago never to by a Duncupped tire again. PR2's I get 6-7k out of without any major cupping. But yeah, scalloping/cupping is just due to braking. Some tire designs cup way more than others. Nothing in my experience cups as bad as Dunlops though.

 

[nabusa]

The set of CT'2 lasted me about 12,000 before they started cupping. The skinko 005 cupped on me. My entire front folk assembly is brand new so I don't know why it cups either. I tried different psi, but still get the same result.

 

[binx]

I talked to the guy at dunlop and he said its not normal. I am running them at the pressure recommended buy dunlop. No difference in wear to my previous ones. He said to use the roadsmart 2's because the q2 is more a race tire rubber.

 

[Tufbusa]

+1000 on all counts. I vowed years ago never to by a Duncupped tire again. PR2's I get 6-7k out of without any major cupping. But yeah, scalloping/cupping is just due to braking. Some tire designs cup way more than others. Nothing in my experience cups as bad as Dunlops though.

I'm curious, what makes you think braking is the culprit? Is it the pads you use, shorty levers or just the direction you're looking when you pull the lever?

I really don't know what causes a front tire to cup. When I talk to five different guys who say they know I get five different answers.

Confused!

 

[VIPER]

The set of CT'2 lasted me about 12,000 before they started cupping. The skinko 005 cupped on me. My entire front folk assembly is brand new so I don't know why it cups either. I tried different psi, but still get the same result.

I cant see dunlop suggesting 42psi cold on front tires. Thats way to high. i chatted with a couple suppliers and a couple of the local racers here 42 is way to high.

 

[binx]

Im running 39 cold f&r and check my tires a lot now and never above 42.

 

[jphilipson]

I'm curious, what makes you think braking is the culprit? Is it the pads you use, shorty levers or just the direction you're looking when you pull the lever?

I really don't know what causes a front tire to cup. When I talk to five different guys who say they know I get five different answers.

Confused!

To clarify, it is due to braking, and cornering, to be fair. Anything that places a lot of force on the tire. Look at it this way, think of each of those rubber sections between the grooves and sipes on a tire as individual erasers. Now take a pencil eraser, and drag it upright along a surface. You will see the wear on the eraser is not distributed evenly on the eraser - most of the wear is on the leading edge. The same happens with a tire, that when braking, is essentially becoming a giant eraser on the road surface. Each of those blocks of rubber between grooves is having the same thing happen that was demonstrated with the eraser.

 

[Wag]

Wow. Where to begin.

Tire pressures seem to be okay but bear in mind, that's a cruising speed tire pressure, on a normal temperature road with an average weight of combined bike and rider. You may find that you have to change the pressure for your particular riding conditions and practices. There really isn't any one correct tire pressure to rely on for every rider, every bike, all conditions. The tough thing is, it's difficult to experiment when it takes a thousand miles before you can tell what the effect of the change is!

But wait! There's more!

Your suspension needs to be set up right. If the cupping is on one side only, then I would bet dollars to dimes something is wonky with your suspension. Tires can tell you, believe it or not, when there are very minor imperfections in your suspension. If you put in new aftermarket internals (valves and springs), you may find the problem solved. Ohlin's and Racetech are two of the ones in which I have a great deal of confidence.

If wear is happening on both sides, it may mean that there is nothing wrong with your suspension. Or maybe you just have the WRONG suspension. Again, better internals, especially valves, may very well solve your problem.

If you're a heavy guy over 200 pounds, I would take a serious look at getting new internals, front and rear.

But wait! There's more!

Brakes. It's pretty rare that you can blame brakes for the problem. It's just not a real issue in most cases, I'd save the brake diagnostics for last. When brakes are blamed for cupping, it's really just an issue of trying to compensate for another problem.

That said, your braking habits CAN have an affect on the way the tires wear, no doubt. The ultimate bottom line to all braking (and all other controls on the bike) is that you be smooth about how you execute your braking. The eraser example above was pretty good. With that in mind, if you are in the habit of suddenly grabbing a fistful of brake when you stop, it's only going to amplify the problem. Getting on the brakes in a smooth, controlled fashion will mitigate the majority of that problem, if, in fact, that is the problem.

If you yank on that brake lever, the tire will skid for a brief moment and the effects described in the eraser example above are amplified a thousand times. If you're smooth on the brakes, it reduces that effect. That is not to say that you have to be slow in braking. You can be smooth and brake very quickly but the subtle difference translates to how your tires wear. One of the things I always teach in class. (For that matter, smoothness in all of your controls reduces wear on nearly every moving part!)

--Wag--

 

[jphilipson]

Brakes. It's pretty rare that you can blame brakes for the problem. It's just not a real issue in most cases, I'd save the brake diagnostics for last. When brakes are blamed for cupping, it's really just an issue of trying to compensate for another problem.

I have to respectfully disagree with that statement. Nothing creates more friction on a tire than braking. Therefor, braking wears a tire quicker than any other force applied by the bike. You can test this yourself quite easily. Go for a fast ride in the twisties for 10 minutes, stop and measure tire heat. Then go on a straight road and do 1 or two quick stops from 50-60 mph and measure heat.

 

[The Big Red One]

To clarify, it is due to braking, and cornering, to be fair. Anything that places a lot of force on the tire. Look at it this way, think of each of those rubber sections between the grooves and sipes on a tire as individual erasers. Now take a pencil eraser, and drag it upright along a surface. You will see the wear on the eraser is not distributed evenly on the eraser - most of the wear is on the leading edge. The same happens with a tire, that when braking, is essentially becoming a giant eraser on the road surface. Each of those blocks of rubber between grooves is having the same thing happen that was demonstrated with the eraser.

Sport Rider or MotorCyclist did a nice in depth article about why tires cup and some tricks to minimize it a few years ago, the article might still be online. I don't remember the specifics, its too early and not enough coffe yet lol. Informative article tho.

 

[Wag]

I have to respectfully disagree with that statement. Nothing creates more friction on a tire than braking. Therefor, braking wears a tire quicker than any other force applied by the bike. You can test this yourself quite easily. Go for a fast ride in the twisties for 10 minutes, stop and measure tire heat. Then go on a straight road and do 1 or two quick stops from 50-60 mph and measure heat.

Friction, yes. Wear, yes. Heat, yes. Cupping. Nope.

Cupping is a manifestation of abnormal wear, heat and friction caused by some other problem. Braking doesn't cause cupping on it's own. Ever. Something else is causing the problem, the problem being cupping, not normal wear and tear.

--Wag--

 

[card16969]

one thing ive learned if you have any front suspension problems or have it set too firm for you it can cause some cupping if you have rough roads at all.... our roads here are absolutely horrible

 

[Wag]

one thing ive learned if you have any front suspension problems or have it set too firm for you it can cause some cupping if you have rough roads at all.... our roads here are absolutely horrible

I'm not so sure I buy that one either, however, I have no evidence for or against.

--Wag--

 

[skydivr]

here is what mine was doing.

with some advice from Tufbusa I put race tec springs in and that made all the difference. I was changing front and rear every 2-2500. I now have 3000 with 1 track day on them and the front still looks great and the rear will need to be changed after this Sundays ride. I think I'll be at 2 rears to one front now.

This front ain't great, it's done and needs to be replaced - there's zero tread left on the sides and look at the profile as compared to a new tire - good job on burning those sides off!!

 

[skydivr]

Too add: I have been having a 'chattering' or 'oscillation' in my front for awhile. I thought maybe it was my rotors (see other thread for my rotor nightmare/fiasco). But, when I put those new bearing in last week, my front end really smoothed out. I could be that will also fix my cupping issue, it will be interesting to revisit this when I get a few city miles on it.

 

[jphilipson]

Too add: I have been having a 'chattering' or 'oscillation' in my front for awhile. I thought maybe it was my rotors (see other thread for my rotor nightmare/fiasco). But, when I put those new bearing in last week, my front end really smoothed out. I could be that will also fix my cupping issue, it will be interesting to revisit this when I get a few city miles on it.

Sounds like a bad bearing to me.