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Old, Bold rider
2002 Honda 919, 1976 Yamaha XT500 cafe, TC-JAG TZ250
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What changed?
Roadracing.
Up until the Japanese horsepower wars starting with the 1969 CB750 rapidly followed by Kawasaki H1 and H2 triples, even factory racers were using Dunlop Trigonic tires constructed of synthetic rubber / carbon black compounds. They were barely adequate for the racers until horsepower and weight increased, whereupon the deficiencies of the existing compounds started to show. Enter silica compounds. The Silica added to rubber buttressed it much better than carbon black compounds due to its molecular structure: a twisted helix of tunable length which flexed with the rubber rather than carbon black compounds which not only hardened the rubber, but were also non polar, meaning it is hydrophilic which can bond with water, significantly compromising wet traction. (yeah, I learned about all of this when a Dunlop rep showed up at Morris Industries and enlightened us on it, and many other aspects of tire construction.) The addition of silica (actually trending toward polysiloxane formulations) which is polar, meaning the compound is net hydrophobic, greatly improved wet traction. The construction was still bias ply and the aforementioned performance and weight increases were showing just how bad that construction was when it came to dealing with it. After several very bad crashes due to tires catastrophically failing pointing out the deficiencies of bias ply construction Michelin went to work and in 1983 the first radial rear tire shod Freddie Spencer's 500cc title winner. The end result was tires caught up with the burgeoning horsepower wars which badly overwhelmed the bias ply tires, and suddenly the chassis and suspensions started to show serious deficiencies when faced with 150+ horsepower and much greater cornering speeds. Fast forward to 1987 when Michelin, drawing heavily on lessons learned on the track, introduced the A59X and M59X radials, BTW just in time for the 1988 Honda Hawk which came with terrible bias ply Bridgestones. God, I hated those blocks of granite! The factories latched onto that and started making true sportbikes that with greatly improved frames and shocks took over the street, and were a godsend to club racers. Even nakeds benefitted with better frames and suspension, though not nearly as much as sportbikes.

Needless to say all the other tire manufacturers embraced the radial tech in a desperate attempt to try and keep up with the more demanding motorcycles, a very good thing!

Then there's the volumes of information on chassis design and implementation, a necessity brought on by the much better tires.
But that's another story.

Rob
 
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Wanna free cat?
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Discussion Starter · #3 ·
I used to think that Cheng Shin was a purty good tire, for the price.

P.S. Fast Freddie prolly could have won on a set of Cheng Shins.
 

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Wanna free cat?
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Discussion Starter · #5 · (Edited)
What is the meaning of Rub a dub dub?
Well, rub a dub dub was three men in a tub, in early American literature.

Rubber dub dub was a play on the phrase in reference to the fledgling compounds of motorcycle tires.
Those three guys in the tub prolly had no rubbers, at all.
At least I had my Cheng Shins.
roflmao

P.S. Welcome to the forum
 
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