uneven front tire wear

[howie333]

2017 FJ-09

Under 5K miles on Dunlop Sportmax 3 front and rear. Tire pressure- 36 front/40rear. Rear tire is in great shape.  Andreani fork cartridges. Sonic rear shock. rider Sag set 44mm measured @ 35% fork travel using a Mototool to measure sag. 165 lbs. rider weight. Cartridge springs- listed @ 8.3 ; I ride semi aggresive cornering (east Tennessee).  I think my rebound screw is all way out, but barely once bounce back when forks pushed down and released. Compression is set @ mid range Still sort of stiff and semi hard on bumpy roads. Handles well thou. Why is my front tire doing this ? Scalloping or cupping ?

 

Thanks ...

[betoney]

1 hour ago, howie333 said:

I think my rebound screw is all way out, but barely once bounce back when forks pushed down and released.

When you say rebound screw is all the way out, I am assuming you mean that the rebound clicker is fully turned counter clock-wise? is this correct? 

If your rebound damping is set to fully open- meaning almost zero rebound hydraulic damping, you are basically riding the spring, when you press down on the front end it should rebound back up very quickly and feel bouncy.  If that isn't the case your fork leg could possibly be binding.  When your damping is correct and you press down and release it should move down and back up smoothly and controlled with no downward binding or stiction and not springing back or slowly dragging upward.

[OZVFR]

I wouldn't be expecting a lot more than 5000ml on a Sportmax 3 front tyre.

My last Rosso III's (equivalent tyre to the Sportmax) lasted only 4400ml on the rear and 5200ml on the front.

From the look of your tyre you lean a bit, but not a lot. You will never wear out the middle before the sides on any front tyre, at least I never have.

Scalloping is a normal wear on that type of tread pattern, and not much you can do to stop it, but correct damping adjustments will lessen the affect.

Check front fork damping adjustment as Betony advised, it helps to have a second person while doing it.

Front is always harder to tell from just bouncing it due to stiction, but not impossible to at least get an idea of where its at.

Adreani cartridges are known for being a bit harsh, but it should never be set to zero rebound.

I usually get rid of my front tyres while they still have usable tread because I don't like riding on one that has a triangular shape.

[howie333]

2 hours ago, betoney said:

When you say rebound screw is all the way out, I am assuming you mean that the rebound clicker is fully turned counter clock-wise? is this correct? 

If your rebound damping is set to fully open- meaning almost zero rebound hydraulic damping, you are basically riding the spring, when you press down on the front end it should rebound back up very quickly and feel bouncy.  If that isn't the case your fork leg could possibly be binding.  When your damping is correct and you press down and release it should move down and back up smoothly and controlled with no downward binding or stiction and not springing back or slowly dragging upward.

Yes right side cartridge screw turned counter clockwise.; It springs back quickly w/ no lag for adjustment after pushing down forks, but I'm pushing by myself w/ no help. Should my weight be on the bike and have helper push forks? Fast Bike Industries in Henderson NC assured me they installed the right springs and valving for my weight. There's only a few thousand miles on the fork oil.

Edited June 4, 2023 by howie333

[betoney]

9 minutes ago, howie333 said:

Yes right side cartridge screw turned counter clockwise.; It springs back quickly w/ no lag for adjustment after pushing down forks, but I'm pushing by myself w/ no help. Should my weight be on the bike and have helper push forks? 

Is the rebound adjuster always fully open? meaning no damping?  as @OZVFR mentioned, your rebound settings shouldn't be at zero.

Your damping adjustments control the SPEED of the spring compressing down and or rebounding back up.  You don't want the suspension to bounce, you want it to move up and down in a controlled manner.  You can set baseline settings while in the garage or driveway but most of your adjustments should occur while riding.  I have always kept a straight slot screwdriver in my tank bag for suspension tweaks while riding. 

[OZVFR]

As a baseline you should adjust rebound until it first starts to slow down the fork return action, after that you’ll need to adjust by test riding. 
Best with someone holding the bike upright from behind while you stand on the pegs holding rear brake (not front) and bouncing the front. 
There is no perfect for everyone setting, it has to be adjusted to your riding style. 
Have you checked the other fork to see what adjustment the compression damping is set to?

I had my forks done by Racetech, so they came back already set up by the shock dyno (I didn’t leave it like that because I didn’t like it after test riding it), but cartridge’s often come set to zero as they’re not tested  

 

Edited June 4, 2023 by OZVFR

[bwringer]

We're sort of confumblefuzzing two separate topics here...

1) I think we're all agreed that's just perfectly normal front tire wear. That's just how sporty front tires wear on sporty motorcycles. Note that it's more worn on one side than the other, but acalloping and asymmetric wear are perfectly, 100% normal. That tire had a good, long life, longer than most of that make and model, and has earned its rest in Rubber Valhalla.

2) Your damping adjustment doesn't seem to make any sense. Some good advice above; you may find that the bike handles better once you've untangled this. This is not really related to tire wear.

[johnmark101]

You obviously have some great twisty roads near you and ride them often.  In this case, wearing out the sides first is not unusual.  I have some good roads near my home as well and wear the sides ahead of the center.  I hate the way the front feels once the tire is worn in this manner, but it's normal when riding mostly twisty roads.

Your tire also appears to have a bit of scalloping.  For what it is worth I have had the same, but to a lesser degree when running the Dunlops.  According to a friend of mine the Roadsmart 4 does not wear like this, and that will probably be the next tire I try on my Tracer.

Edited June 5, 2023 by johnmark101

[duckie]

FWIW…….my first sport bike was a 95 900ss ducati.

At first , I would go through two fronts to one rear…..until I learned how to corner properly. Then it was two rears to a front. 
 

What did I change in my cornering…..not being off the throttle in a corner. I started using neutral throttle or maintenance throttle in the corners. 
 

Neutral throttle is not closing the throttle nor opening the throttle. Maintenance throttle is just adding a little throttle to keep from slowing down in a corner.

If you close the throttle while cornering, you are putting extra weight on the front as you corner causing the wear seen here. 
 

Sometimes it aint the tire that is the issue.

[duckie]

It is best to think in term of slow or fast when adjusting dampening settings cause that is what really is happening. 
 

Rebound is what keeps the tire in contact with the road when encountering rough surfaces. Improper settings can result in pogoing and packing. Pogoing occurs when the rebound is allowed to move to fast, packing occurs when the rebound moves to slow. 
 

A good starting point for setting rebound is to set it so that the fork clamps not to overshoot their resting postion. Overshoot is when the clamps go over their resting position then comes back down to resting postion. 
 

Try for a setting that lets the clamps come back to their resting postion with no or very minimal overshoot.

Resting position is where the clamps are when the motorcycle is not being bounced up and down.

[howie333]

Would a single compound tire make more sense, since I'm not putting on highway miles, and mostly cornering to get a more even wear? Seems I'm wearing the soft compound down rather fast; also would their be a problem to mix tire brands sa. a Dunlop Sportmax 3 rear w/ a new Continental road attack 3 rear tire ? 

Thanks ...

Edited June 19, 2023 by howie333

[How2]

I had 2 set of tires do this.

The problem was that the headset bearings were nicked Under 18k miles.

Yamaha is notorious for not putting enough grease in their headsets or swing arms. There is a test to see if the steering bearings are nicked. You do have to drop the wheel and front forks to do that. I took it to a shop to check it but they just lifted the front end an moved the bars.

They said the bearings were ok. But they were not on inspection as described.

Once the bearings were changed, the problem was solved.

Peace out

[roadrash83]

Did you replace the bearings with roller or ball?

[PhotoAl]

Some tires are more prone than others.  I've had Michelin Road 5 and Pilot Power 5s do that on two different bikes.  Road 6s are wearing much more evenly.  Several factors including tread block design, tread compound and carcas stiffness.  Good to check and grease head bearings.  Tightening specs for ball bearings are different than tapered bearings.  Folks have different opinions on which is better - imagine that just like oil and ....  🙂 

 

[Brentinpdx]

Dave Moss has some good info on suspension tuning for motorcycles. You can try his remote tuning.
 https://davemosstuning.com/remote-tuning/