Jump to content

Tire cupping, what causes it?


Guest OldGold

Recommended Posts

Guest OldGold

I have an 83' VF750F and the front tire is cupping more so on the left side of the tread but also on the right.

The center is wearing normally. When riding especially in the wind it feels squirrelly and I am not fond of that feeling.

Now, I don't just want to put new tires on it I would like to find and cure the cause before spending my pennies on new shoes.

Just a little background on the bike it has Dunlop arrowmax GT 501 F tires on it, the forks don't leak I am running 6 PSI

in the forks it has the original springs in the forks and to me they feel a little squishy. It has TRAC anti dive but it is useless

(have been pondering progressive springs for the front) new EBC HH pads fresh calipers, no binding or vibes to speak of.

I ride secondary roads and back roads exclusively (no freeways) I ride fast but not aggressively and don't take corners

to fast either I don't know where to begin to look for issues. The bike is bone stock (other than exhaust) so no fancy fairings or luggage. Please help

Link to comment
Share on other sites

That makes sense the crown on the roads here are pretty hardcore

and yes I do trail brake, to burn off speed when approaching a stop. But in the corners

I try not to but I am a bit of a pussy and tend to do so

I love this site you guys really know your stuff

Y'all have given me some things to ponder

Do any of you know of some good books on technical riding...

there is a whole lot I don't know

Thank you :fing02::beer:

Link to comment
Share on other sites

  • Member Contributer

CUPPING:

To begin with improper balance has nothing to do with cupping on a

motorcycle tire. Improper balance will merely cause your bike to

vibrate within certain specific speed ranges. Cupping, which is more

accurately described as scalloping is a natural wear pattern on

motorcycle tires and it will always follow the tread pattern. It is

not a sign that you have bad suspension parts. It merely shows that

your tire is indeed gripping the road when you make turns (thank you

for that Mr. Tire!). This cupping develops within the side wear bands

of a leaned motorcycle. The leading edge of the tread does not flex

much as it grips the road and the rubber is scuffed off the tire in

that area causing a depression. As the tire rotates, the pressure

moves to the trailing edge of the tread pattern where the tread flexes

more causing less scuffing so less material is ground off the tire.

The more complex the tread pattern, the more complex the cupping

pattern will be. The softer the compound of the tire, the sooner this

cupping will develop. Radial tires are more prone to cupping than are

bias ply because the compound of radials is softer.

Link to comment
Share on other sites

  • Member Contributer

Also, the tyre you're using will be more or less susceptable to it. For example, on my bike, BT020 fronts were always scalloping very noticeably. However, the BT021s and PR2 that I have used since have not shown it at all, with similar riding histories.

Link to comment
Share on other sites

My experience has been, most Dunlops that fit VFRs cup more and earlier than most other tire brands, so take it into consideration when you buy you next set of tires. What's bad is, the deterioration that I noticed in handling goes up exponentially with the rate of cupping on the front tire. I did not experience the same on the rears though.

Link to comment
Share on other sites

I have been pondering getting Bridgestone BT 045 's for it

a buddy of mine has them on his SV50 and they seem to be doing pretty good

on his ride

thought of Pirelli's and Avon's but they are pretty spendy in these parts

and it is hard to find v rated tires in my size most have only h rated unless I up size

and a lot of places like Bike Bandit ... won't ship them up here, only lower 48

Will have to do some more diggin

Link to comment
Share on other sites

I have been pondering getting Bridgestone BT 045 's for it

a buddy of mine has them on his SV50 and they seem to be doing pretty good

on his ride

thought of Pirelli's and Avon's but they are pretty spendy in these parts

and it is hard to find v rated tires in my size most have only h rated unless I up size

and a lot of places like Bike Bandit ... won't ship them up here, only lower 48

Will have to do some more diggin

One more time...

Check Pete's Superbike, he is near Montreal, ships pretty well anywhere. Prices are pretty good and he can get most sizes. I don't what size your year takes though, so I may be wrong. Seems to me he's got every size of PR2 I can imagine.

Brian

Link to comment
Share on other sites

WOW! thanks for that link Brian! :fing02:

They have pairs for what people are paying for singles here. :cheerleader:

And I would gladly give my money to a shop from back home :fing02:

Link to comment
Share on other sites

  • 1 month later...

Busy Little Shop explanation is 100% correct. The only thing I would add is that tire wear on the left will always be more pronounced in the US because we drive on the right side of the road. The radius of our left hand turns are about twice as big as a right hand turn, which enables us to also take them a little faster than a right turn and we can lean the bike a bit more. You see more cupping on the front because the wheel is turned, but the inertia wants to keep going straight ahead.

For a a really good article on tire wear read : http://www.rattlebars.com/tirewear/index.html

Link to comment
Share on other sites

Archived

This topic is now archived and is closed to further replies.

×
×
  • Create New...

Important Information

By using this site, you agree to our Privacy Policy.