Front Tire Wobble Rear Tire Cupping

[zedxmingus]

Looking for some advice on troubleshooting a newly installed pair of tires. A thousand miles or so ago I installed a set of Metzler Roadtec Z6 tires on my '08 with 6500 miles (or so) on it. Right from the start I noticed a slow speed wobble in the front end. The wobble was similar to the wobble I would get when my '02 R1 front tire was reaching end of life. I chalked it up to a balance issue and planned on attending to it next month when the bikes go away for the winter.

As I was detailing the bike this week I ran my hand over the rear tire looking for nails or any issues that may have come up since my weekend ride. I was surprised to feel cupping when running my hand clockwise on the tire. Itseems that ever groov has a raised edge on it. I removed the wheels myself but had the dealer do the actual tire demount/mount and balance. Any advice what my first step in troubleshooting should be?

I run the factory recomended air pressure btw and ride two up almost always. I am 270 6'4" and she is 125 5'5". The bike has a Givi 55 loaded with rain gear and jackets for the cool nights, rear shock setting is set to hard.

Any advice would be greatly appreciated.

-Jeff

 

[ESPrider]

Check the tire pressure recommended by the Tire Manf, not Yamaha. I would also run a little on the higher end of the spectrum, especially on the rear tire, given the total weight you're carrying.

 

[SLK50]

I don't think I've ever seen cupping on a rear tire before.

Are you applying the rear brake while leaned over in a turn?

 

[escapefjrtist]

Metzlers will wobble just a bit at low speeds. Nothing as severe as the (in)famous Avons but a little nonetheless.

Regarding the rear cupping... I have it on every set of tires I run. You can try reducing the rear dampening a few clicks, but the load you're running will dictate how far you can go. As mentioned above, keep tire pressures on the higher end. Most folks are running 42 rear and 40 front with good success on most brands. Question on the rear Metzler. Did you purchase the FJR spec tire or the standard Z6?

FJR's are hard on tires...find a brand that works well for your riding style and load, and stick with them.

--G

 

[UHOH]

I was surprised to feel cupping when running my hand clockwise on the tire.

It seems that every groove has a raised edge on it.

clockwise doesn't communicate what direction you're running your hand

are you going same direction as tire rotates or opposite?

In my book, cupping is not the same as "every groove has a raised edge on it."

you oughta seek out a local bike night gathering (not cruisers, they use different type tires)

and look at other tires in the middle of their life.

 

[GalaxyBlue]

I was surprised to feel cupping when running my hand clockwise on the tire.

It seems that every groove has a raised edge on it.

clockwise doesn't communicate what direction you're running your hand

are you going same direction as tire rotates or opposite?

In my book, cupping is not the same as "every groove has a raised edge on it."

you oughta seek out a local bike night gathering (not cruisers, they use different type tires)

and look at other tires in the middle of their life.

The raised edges you are referring to has happened to me with Avons and Bridgestones, And i believe the cause is too much engine braking in the twisties. I am super hard on tires in the corners and use the motor rather than brakes. At least, That is what i believe anyways!

 

[zedxmingus]

Thanks for all of the input

-I am running the higher load rated tire suggested for the FJR.

-I am running my hand opposite of the direction of rotation, sorry for being unclear. I laughed at how dumb that statememt was after I read your response. Thank you.

-It appears that my rear tire pressure should be increased from the comments below. I will increase it tonight.

-I am not using the rear brake in most scenarios. I picked up that bad habit from the R1 and my other sportbikes. I mostly use the front brakes on those machines and the habit has carried over to this bike as well.

-I had a conversation with my pillion this weekend about feeling like we are reaching the "bottom" of the shock rebound in some harsh bumps and drops in the road. It may be time to educate myself on suspension setup for this machine.

Thanks to all who responded, I appreciate the input. I have found the forum to be very helpful in my farkle purchases and on mechanical questions.