I believe this is more of an issue on sport and race bikes. From what I understand it has to do with the radius of the tires matching. They are designed so that when a bike is leaning hard the friction patch on the tires balance. I ran a dunlop on the front of my R6 and a Pirelli on the back for a few hundred miles. I could feel the bike "push" during high speed turns. I changed to both pirellis and the problem instantly disappeared. Now on a Harley we all think we can lean them way over in the twisties but it is nothing compared to a sport bike. So on HD's I don;t think mixing would be any trouble.

 

i had a dunlop on the rear and a metzler on the front and it was down right scary. take my hands of the bars and they would shimy like all get out. put a dunlop on the front problem gone

 

In years past only baggers ran the same pattern front and rear, and they weren't noted for great handling. The original FX came with a ribbed tread on the front and standard tread on the rear Goodyear. The old 70's choppers usually had an Avon Speedmaster on the front and a Goodyear tread on the rear. Not all of them were stretched out ridiculously, and a chop with a 6 or 8 over front end handled pretty well. Sportsters in the 60's and 70's also ran the ribbed front 3.50-16 and a 4.00-18 tread Goodyear and as I remember handled just fine. The limeys were the best handling bikes back in the day and most featured a ribbed front 325-19 and tread on the rear Dunlop K70 400-18.

 

My front Metzler did that until I put more air in it. Metzlers require higher PSI.

 

Thanks for all the great input. All things considered, I went with a Metzler on the front and an Avon cobra on rear. The metz does take psi of 38-41 and avon emphasized 42psi on rear. Theres definitely a difference in tread so I will keep everyone updated as to the ride feel and if I experience any "pushing". I will probably ditch the cobra and go metzler if that happens.

 

Northside thanks for the knowledgable input. I did not realize thats how they rode'em back then, good to know but it sounds like Im backwards to the tread patterns on how they used to ride them. I got the s style or v whatever it is on the rear and standard looking tread on the front. We will see.....if it works out. Thanks