TRIANGULARS

[Allred]

In KC's recent Cycle World missive he reminisces on his early days of the 1960s. And in his "Home is Where The Wrench Is" section he talks of Dunlop triangulars, which shot me back to those days when there was so little choice in the way of tires.
https://www.cycleworld.com/story/blogs/ask-kevin/all-the-worlds-a-shop/

In the UK there were two main tire manufacturers, Avon, operating from Melksham, Wiltshire, and Dunlop, founded in Dublin Ireland with its main factory in Erdington, Birmingham (UK). There were one or two off-brand motorcycle tire manufacturers but no self respecting cafe racer would be seen dead using them.

And from these two manufacturers you had the heady choice of, well, not much at all. Avon had their Speedmaster MKIIs which consisted of a ribbed front tire and a barely rounded, heavy tread-patterned rear.  Dunlop had their K70, which had an even more blocky tread pattern. Like Chevy vs Ford or Coke vs Pepsi, there were advocates of both. Personally I was an Avon man and wouldn't be seen dead with a K70 on my motorcycle!

Avon did make a "racy" looking tire called the "Avon GP", it was more rounded, had less blocky tread, was more expensive, and didn't last as long as the "standard" Speedmaster MKII, partly because it had a slightly softer compound, but mainly because it had less tread on it! And as we struggled to get much more than 1,500 miles to a rear tire, my apprentice wages didn't stretch to the cost of Avon GPs.

Dunlop upped the anti in around 1968 when they introduced their K81 model, a radically innovative design with a rounded aspect and racy-looking tire pattern. (later renamed the TT100 after Malcolm Uphill lapped the IOM at 100mph in 1969 on his Triumph Bonneville). It was also innovative in that it was recommended to be used on the front as well as rear wheels, before this everyone used ribbed front tires.

Around this time Honda had introduced its 4 cylinder CB750, and its frame design, weight, power output and engine characteristics played havoc with tires of the day. At high speeds they found that front ribbed tires like the Avon Speedmaster had a tendency to want to creep off the rim!!!!!!! The fitting of Dunlop's K81/TT100 tires front and rear seemed to cure this.

Then they found that machines like the CB750 had such rapid acceleration that rear tires were splitting at the center where the tires joined during manufacture if fitted "the wrong way around" It was realized that directional tires were needed and directional arrows began appearing on tires.

Because of the problems with tires of the day on such rapidly advancing machines, I began using racing "Triangulars", the tires used by professional racers on the track. They had an extremely "triangular" profile to them, and gave a feeling of either upright, or full lean, but they gripped far better than regular road tires, and surprisingly, actually lasted about 50% longer than regular road tires, which offset their hefty price tag as they were almost twice the price! They had a very stiff sidewall and were a bear to fit but so worth it as their performance was far superior for fast roadwork........and you were riding on the same tires as Mike Hailwood!!!!

We don't know how lucky we are with today's vast array of superb motorcycle tires.












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[motogrady]

Very cool piece Mr. Allred.  

Back then, I was running pretty much anything I could afford that would fit the rims, and didn't have thread showing.

Street or dirt.  

I do remember an affinity, and spending what I considered a fortune, on a few sets of Trelleborgs from Sweden.  This, when I was convinced I had found my calling as a professional Motocross Racer lol.

Nowadays, it's Bridgestone Spitfires on the CB.
Alas, unlike the threadbare model of years gone by, mainly the chicken strip version of the present!

[oldironnow]