Tire help for BUB

[aching_ass]

Hi,

'bumpy_roads' here. I lost my password and changed emails so had to re-up. I am working on a '97 883 with a 89CI S&S power plant and will test it out this year with hopes of AMA next. I'm thinking about Avon AM26 Roadrider V-Rated 149 MPH Bias. Any suggestions? I have gone through forum topics and Internet looking for info and come up pretty dry? Do I want grip? More or less rubber on salt? Any particular tread design? Or none at all!

Thank you, Bumpy

[k.h.]

The APS/PBF 1650 record holder in 2004 ran on ZR rated Avon Azaro ST tyres.  They have an aramid band that precludes the tyre from pulling itself away from the rim due to centrifugal force at speed. 

[dwarner]

Password hint!!

Use the same password for every forum, news group, etc. you sign up for.

DW

[joea]

very much application specific......but generally speaking...
...less rubber on salt....harder compounds work well.....avoid
prolonged wheel spin......in you application the v-rated would likely
suffice......if you plan on speeds over 160's, consider going to a regular
zr rated radial on rim designed for it.......they have proven very durable on the salt.........

[k.h.]

If it was me, and it's not, I'd consider running an Avon Azaro AV45-ST 110/80 R19 (front) tire on both the front and the rear.  It will fit a rim from 2.15 to 3.00 inches, per factory specs.  It's 26.10 diameter & 4.30 wide.  It's R rated.  But (!) I would advise one to turn the rear tire around to roll AGAINST the arrow. 

[JackD]

Splain the lap seam / directional requirement shown with the arrow and the difference in forces between the front and rear tire in German.
Never mind, do it in American, not English and we will translate. 

[k.h.]

The Azaro ST has eight layers in the build process:  1. Bead and bead filler (apex)  2. Tubeless lining 
3. Radial ply  4. Chafer  5. Radial cut belt   6. Sidewall  7.  AVBD wind  8.  Tread 

AVBD (Advanced Variable Belt Density) offers high stability at all lean angles, including none at all.   SBC (Spiral and Belted Carcass) has two extra belts to increase stability and grip under heavy acceleration for speeds of 168+ mph.  Spinning reeeaaallly fast (unlikely with a pushrod motor, no offense) may cause the tire tread to rip away from the aramid belt. 

Today I am completely unable to translate hard science into simple English regarding front tires on the back.  (A cop out.  You'll do a better job of 'splainin').

[JackD]

Pertty good.
The HD is particularly good in the traction department as evidenced by it's long term successes on the mile.
The timing of the power pulses is such that it recovers during the dead pause to hook up again and is ready for more power.
UJM multies are almost electric in their nearly constant power application and once they run away, they don't recover as well.

The point of the arrow:
Wrap your tire with a single length of duct tape in the direction of travel and observe the lap seam at the end.
That is to simulate the wrapping method used to apply the various layers of rubber to the tire.
Now sit, look, and think about it.
Remember what forces are acting on it when in hard use.
The front tire will do a higher percentage of the braking and the rear will drive you down the road.
Now decide which direction you want the free end of the tape / lap seam to go and see if the factory is correct.

[k.h.]

Well, for the front tire in an A pushrod class (and no front brake) one is probably doing well by running it with the arrow.

For the back tire, traction wheel, in that same A pushrod class, against the arrow oughta' be better.

By the way, I hold the most theoretical land speed records with my fleet of theoretical motorcycles.

[aching_ass]

Thanks to everyone for responding. The research continues and all the info helps.

Bumpy

[JackD]

"Theory becomes fact when the rubber meets the road." (me)

[Xea]

Isn't it a requirement to have the same speed rating as the record in the class you are going to run?

[aching_ass]

Isn't it a requirement to have the same speed rating as the record in the class you are going to run?

It would make sense. I'll check rules again.

I went with Avon AM26 Roadrider V-Rated 149 MPH Bias. The ZR rated Avon Azaro ST won't fit my wheels. If bike runs faster than I'm anticipating (I hope!!) I'll change wheels for a higher rated tire.

[tortoise]

Isn't it a requirement to have the same speed rating as the record in the class you are going to run?

2.Q. TIRES
It is recommended that tires are rated for the appropriate speeds
and, use is at the sole discretion of the owner/participant. The rider
has the sole responsibility of inspecting the condition of the tire
before and after each run.

Slim should like the comma after the "and".

[Dakin Engineering]

Just a hint; best make sure your shoes are rated for the expected performance in your particular class. And if you don't have a steering dampner, get one.

Sam