Yamaha FZ-09 Forum banner
1 - 17 of 17 Posts

·
Registered
Joined
·
137 Posts
Discussion Starter · #1 ·
Need some help here. I attached a couple pics. Bike has 1100 mostly touring miles on it with the occasional twisty road thrown in. 300 or so miles are two up riding. Temp ranges of riding 45-70 degree days. Mostly dry pavement riding. Stock suspension. Stiffened up rebound and preload on rear shock.

The front of the groove is worn down while rear of groove isnt. Cause?? Is it normal wear or indicative of some issue. Im by no means a set up expert and have never riden on a track but the rear of this bike does not inspire alot of confidence in a corner that isnt perfectly smooth.

Rear tire. Front doesnt have issue.

Thx for input. image.jpg

image.jpg
 

·
Registered
Joined
·
835 Posts
Something about the way the tire flexes as you're accelerating, the front lip of the groove digs in while the rear is skipped over.

I'm sure someone can give a super technical reason but I can draw a bastardization in MSPaint for ya!
 

·
Registered
Joined
·
657 Posts
This is from lack or rebound, and riding two up with luggage.

 

·
Registered
Joined
·
835 Posts
IMG_20140522_073959.jpg

2k miles mostly highway, lots of wheelies.
 

·
Super Moderator
Joined
·
5,751 Posts
Turn the rebound setting on the rear shock...COUNTER-CLOCKWISE, that will slow the rebound down. Too much rebound will cause excessive wear on the leading edge of the groove and cause it to wear away faster than the trailing edge. Conversely, if the trailing edge is worn lower than the leading edge, you need to increase or speed up the rebound setting by turning the adjustment screw CLOCKWISE. Always do these adjustments in small amounts...2 or 3 clicks at a time. If the shock doesn't have "click" detents, go about 1/4 turn at a time. Results or changes in tire wear may take several hundred miles to show, depending on how you ride.....straight line vs. twisty stuff. Hope this helps.
 

·
Registered
Joined
·
1,806 Posts
Turn the rebound setting on the rear shock...COUNTER-CLOCKWISE, that will slow the rebound down. Too much rebound will cause excessive wear on the leading edge of the groove and cause it to wear away faster than the trailing edge.
counterclockwise reduces rebound damping which increases the speed at which the shock rebounds. clockwise increase rebound damping which slows down rebound.
 

·
Registered
Joined
·
137 Posts
Discussion Starter · #8 ·
Thx all.
 

·
Registered
Joined
·
226 Posts
Turn the rebound setting on the rear shock...COUNTER-CLOCKWISE, that will slow the rebound down. Too much rebound will cause excessive wear on the leading edge of the groove and cause it to wear away faster than the trailing edge. Conversely, if the trailing edge is worn lower than the leading edge, you need to increase or speed up the rebound setting by turning the adjustment screw CLOCKWISE.
Triple, I'm certain you've got this at least partially backwards, or we're just not using the same terms to describe what's happening.
Straight out of our manual: "To increase the rebound damping force and thereby harden the rebound damping, turn the adjusting screw in direction A (clockwise)."

I too was getting a decent little lip on the trailing edge of the sipes with the stock shock at it's as-delivered position. Turning the adjusting screw in (clockwise) reduced the size of the lips until I maxed it out. Shortly thereafter I installed my Penske. I've got considerably more adjustment range now and after some more ride time I'm sure I can get the tire wear evened out.
 

·
Registered
Joined
·
137 Posts
Discussion Starter · #10 ·
It possible i reached limit of adjustability with stock shock? I have to dbl ch but i think im most of way into increasing damping on my shock. All i kno for sure is rear end of this bike does not inspire alot of confidence around non-smooth corners. :)
 

·
Registered
Joined
·
2,155 Posts
Even with a perfect suspension can't there be asymmetrical wear from powering out of turns?
Yes...all tires will wear that trailing edge when powering out of corners. Most people think they are Valentino Rossi and run such low air pressure on the street..they only get 2k miles out of a rear tire.
 

·
Registered
Joined
·
3,008 Posts
Thanks CD. Back in the day on my SV650 I got about 3,000 miles from a rear tire on the street, so I guess I thought I'm only a mid pack MotoGP rider. ;)
 

·
Registered
Joined
·
137 Posts
Discussion Starter · #14 ·
This is leading edge wear.
 

·
Super Moderator
Joined
·
5,751 Posts
counterclockwise reduces rebound damping which increases the speed at which the shock rebounds. clockwise increase rebound damping which slows down rebound.
Bobby, my mistake, I was trying to do it from memory, as I didn't have access to my home computer with the CORRECT way to do it. Glad you caught it.
 

·
Super Moderator
Joined
·
5,751 Posts
This is leading edge wear.
Zak........see Bobby Walnuts post #7, he correctly stated what was/is happening on your tire. I had it just opposite, as I was trying to post from memory instead of what I have written down at home on the computer. So, here is what you need to do.

The front edge of the groove is lower than the rear edge of the groove, which signifies that the rebound action is too quick and the leading edge of the tire is making contact (during a rebound situation) before the rear edge of the groove does. In order to correct this, you need to INCREASE the rebound setting (Clockwise direction of the adjustment screw). This in turn will increase the amount of rebound, which slows down the rebound action. You still only want to do a couple of clicks at a time though, or no more than 1/4 turn of the screw, then ride the bike for a couple of hundred miles and check again. Sorry about the mix up.
 
  • Like
Reactions: Crosshairs

·
Registered
Joined
·
137 Posts
Discussion Starter · #17 ·
Thx much!!
 
1 - 17 of 17 Posts
Top