What causes cupping?

[dean owens]

I guess the better question is... could something be wrong with my bike to cause my front tires to cup?

Feel free to simply answer. But if you have the time, here's the background to cause me to ask that.

About a year ago I asked on here about my front end being a little unstable ("flopping" back and forth if I took my hands off the bars) and that the shop said they believed it was because my front tire was showing signs of cupping. That, along with a back tire wearing out, gave me a perfect excuse to change tires. So I got a set of BT-021's. That was about 4000 miles ago.

When I asked about why my tire was cupping someone suggested that I might not be keeping my tire pressure up. That's fair, because I wasn't the best at checking them. Since putting on these new tires I've been pretty diligent in checking tire pressure. I'm a bigger guy so I keep it closer to the top of the recommended pressures.

Update... I put about 2000 miles since I put them on last year and hadn't thought about it. I just got back from a trip to Maine which gave me a little over 2000 more. On the way back it was a lot of interstate riding and my tires developed a flat spot. I guess the contrast caused me to notice my front tire a little more. Turns out I have a good deal of cupping on this tire already. This makes me wonder if there's something wrong somewhere else on my bike causing my front tires to cup.

So what am I doing wrong, or what is wrong with my bike to cause the cupping?

 

[Shamus McFeeley]

Lots of things can lead to cupping.

The road surface - concrete/asphalt
Balance of your tires
The tire /tire compound itself - single / dual / bias
Tire pressure
Your front suspension / steering head

No matter how well you maintain your tires, they are always susceptible to some degree of cupping, its just a matter of time. I have PR2s and they are cupped slightly as well in the front. I believe this was mostly due to riding on the concrete highway with bad steering head bearings over the winter.

If you're tires are cupped so badly after 4000 miles that you are feeling it though the handlebars, and it is affecting your riding, you may want to concider checking your front suspension/steering head bearing condition.

 

[ohgood]

i'd really like to see some pictures of your handlebars and guards, not to mention whole bike.

this is the bestest long winded description of different types of tire wear i've ever found. hope you have a minute or 20 to read it.
Motorcycle Tire Wear
good stuff !

 

[iSteve]

There are plenty of explanations on the internet how it happens. But when I was researching this last year, because the stock front tire was cupped pretty bad at 5k miles. I found that tire design played a big part. Many tire manufacturers will now say things like the new tread design will help resist scalloping.

I do believe it will happen to any treaded front tire. Lot of braking is done with the front so your going to get this kind of wear.

 

[FIZZER6]

There are plenty of explanations on the internet how it happens. But when I was researching this last year, because the stock front tire was cupped pretty bad at 5k miles. I found that tire design played a big part. Many tire manufacturers will now say things like the new tread design will help resist scalloping.

I do believe it will happen to any treaded front tire. Lot of braking is done with the front so your going to get this kind of wear.

I 100% agree with this.

My original BT021's cupped badly.

My last 2 sets (Pirelli Diablo Supersports and my current BT016's showed almost no signs of cupping over their useful wear period. I have to assume that the tread pattern on the BT021's played a huge part in the cupping...and it's pretty obvious when you look at the tire because the cupping seems to abruptly stop right as you hit the groove between tread blocks on the tire....

 

[dean owens]

first time using multi-quote. pretty cool tool.

Lots of things can lead to cupping.

The road surface - concrete/asphalt
Balance of your tires
The tire /tire compound itself - single / dual / bias
Tire pressure
Your front suspension / steering head

No matter how well you maintain your tires, they are always susceptible to some degree of cupping, its just a matter of time. I have PR2s and they are cupped slightly as well in the front. I believe this was mostly due to riding on the concrete highway with bad steering head bearings over the winter.

If you're tires are cupped so badly after 4000 miles that you are feeling it though the handlebars, and it is affecting your riding, you may want to concider checking your front suspension/steering head bearing condition.

just so happens that i got a set of r6 forks coming to me. i'm going to go ahead and use the time to change out my neck bearings as well.

i'd really like to see some pictures of your handlebars and guards, not to mention whole bike.

this is the bestest long winded description of different types of tire wear i've ever found. hope you have a minute or 20 to read it.
Motorcycle Tire Wear
good stuff !

here's my photobucket file. fz6 pictures by jdeano - Photobucket are you looking at putting handguards on? and thanks for the link. i'll check it out later.

There are plenty of explanations on the internet how it happens. But when I was researching this last year, because the stock front tire was cupped pretty bad at 5k miles. I found that tire design played a big part. Many tire manufacturers will now say things like the new tread design will help resist scalloping.

I do believe it will happen to any treaded front tire. Lot of braking is done with the front so your going to get this kind of wear.

hmmm. i guess i have some reading to do to educate myself. i just assumed that a quality tire would wear evenly if the bike was fine and the rider road reasonably.

I 100% agree with this.

My original BT021's cupped badly.

My last 2 sets (Pirelli Diablo Supersports and my current BT016's showed almost no signs of cupping over their useful wear period. I have to assume that the tread pattern on the BT021's played a huge part in the cupping...and it's pretty obvious when you look at the tire because the cupping seems to abruptly stop right as you hit the groove between tread blocks on the tire....

how long did it take for your bt-021's to start cupping? i got them because they seemed to get pretty good reviews on this forum and i thought the dual compound would help them last longer since i mainly commute to work.

thanks all for your replies.

 

[FIZZER6]

how long did it take for your bt-021's to start cupping? i got them because they seemed to get pretty good reviews on this forum and i thought the dual compound would help them last longer since i mainly commute to work.

thanks all for your replies.

My apologies...It was actually BT020's which were not dual compound but the thread pattern was probably the same as your BT021's. Seems like any front tire with a lot of zig/zagging grooves in the tread pattern tend to wear like this...I've observed front tires of many different bikes and any that were cupping seemed to be tires with tread patterns like the BT020. Personally I think it's simple a design flaw.

 

[dean owens]

i decided to look up the patterns and that lead me to this thread.

Roadsmart and BT021 front tire wear pix

my front tire looks just like the bt-021 pictured in this thread (second pic in first post). seems a lot of them in that thread aren't fans of the bt-021's. dang it! thought i did a decent amount of research before getting them. guess not.

 

[greg]

fwiw, i've not noticed any cupping on my bt-021's, it could be problems with specific batches, or machine configurations?

 

[iSteve]

I took a chance with BT-023's have a little over 3k miles on them now and still look and ride great. Have to wait and see what happens at 5k. The ad copy says they last longer then 021's we'll see.

 

[Marthy]

I don't think you do anything wrong. Mine start cupping around 3K on my 6R. That's a 021 thing. Go with a different brand.

I came to my own conclusion that the rubber is too soft and the tire build too much heat and cup. Those 021 never felt "safe" to me anyway... I change them for a different brand and the bike handle much better now, and no more cupping.

There's a good variety of S-T tires out there. I got the Continental Conti-Motion. Really good inexpensive tire (Cycle Gear $255.00 monted for the set) The compound is a little harder then the 021 but the tire is very solid. The 021 always gave me that greasy feeling when leaning, I never felt safe. With those I can grind pegs without any hesitation. I just got a little over 3000 miles and the tire still look like new. I'll be getting another set when due.

One more thing. My spec psi are 36/42. I've been running 40/42 with those. I read in few review that those rubber like to be a little high on psi.

Hope it help...