Roadster Front Tire Wear

[Triple Trouble]

@UberR3 I'm not sure what the point of your post is? Maybe there is a clue in your avatar as to where you got your degree.
I have many years in automotive engineering in design and prototyping as well as manufacturing (now retired) and see only generalisations with no facts. What does,"My point is these variance can be fairly large which means a factory frame is NOT going to be perfectly straight and true. " mean? Are we talking about frames not being within tolerance or in your opinion the factory tolerance is too wide? In this day and age of robotics, laser welding and laser checking of parts I doubt that the frames vary much and certainly won't be out of specification.
I have no specific information on how many Rocket III's have been built to date but a few years ago it was estimated that the number was 16,000. If that number has doubled since then( Not likely) the 5,000+ members of this Rocket specific forum still represents a significant percentage!
Take a look at the profile of the Metz 880 on an R3, especially a worn one and you will notice that there is an unusable area in the region of the tire commonly known as chicken strips about 25mm per side and no amount of bravery will eliminate them. With all alternative tires you can get to within 6mm. This tells me that the tire is wrong for the rim width. On the other hand maybe we are all wrong?

 

[mexican]

except when its flat

Hmmmm, good point

 

[IMFASTTOO]

except when its flat

OR its a car tire

 

[mexican]

OR its a car tire

The only logical choice for the Rocket!!

 

[breeze]

OR its a car tire

car tires are indeed round at least here in new mexico they are

 

[EasTexRIII]

except when its flat

Someone calling me????

 

[Claviger]

@UberR3 You are instantly dismissing real world evidence for theory. The fact is, if other tires (Avons) can perform better in real world conditions across the same subset that the Metzlers failed for, they are a tire capable of coping with a wider set of variables, and therefor a better design.

Trying not to be combative, but your writing style is very dismissive, arrogant, and refuses to acknowledge the reality that there are THOUSANDS of posts of cupping ME880s across various forums, across multiple brands and models of motorcycle. The diversity in reporting reinforces that the tire is faulty, not negates it as you would try to infer.

A motorcycle is not designed from the TIRE out. In the case of the rocket, I can tell you for a verifiable fact, it was designed motor out. The fact that there was a tire that fit the requirements off the shelf economically does not qualify it as "The rocket was designed around the tire", it simply means it was "close enough". If you want an example of a vehicle LITERALLY designed around a tire, go read about the history and root of the Dodge Neon ACR. Engineers opened the SCCA rule book, took the max tire width allowed for the class they targeted and went from there.

 

[dragonjocky]

My experience with front tire cupping is with Dunlop, Avon Ultra II and Michelin Pilot Road tires on my Marauder so I can not speak for the Rocket III in particular. I've experienced cupping with all three mfr's tires typically being noticeable on the Avons and Michelins around 7000miles and progressing throuh the remaining life of the tire. Interestingly it has been directly associated with improper inflation, typically low tire pressure. Diligence in monitoring tire pressure 39-41psi cold minimizes the cupping effect on the Marauder. No that said there is 100lb discrepency in weight and the geometry is different between the two bikes, but I suspect tire pressure is the ultimate culperet on the Rocket as it is on the Marauder.

The simple solution is to only ride the twisties for the first 7000miles, then alter your rides to all slab rides for the remainder of the tire life. Therby you'll capitalize on the entire radius of the tire.

it's the economy of tire efficiency! Just sayin.

 

[Claviger]

Bringing up an interesting point.

Is the 34 PSI recommended pressure the root of the problem?!

 

[dragonjocky]

Bringing up an interesting point.

Is the 34 PSI recommended pressure the root of the problem?!

Is that recommendation by Triumph or Metzler? I'm inclined to give more creedence to recommendations by the tire mfr then the bike mfr.