My Z1 restorers guide suggests that the Z1 needs a ribbed front tire to give it dirrectional stability. Riders who scrapped the ribs back in the day for tt100's were fooled into thinking thier bike was handling better by the way it felt and often crashed.
It does suggest that Continental, Dunlop Red Arrow, and Metzeler eventually made tyres that worked better but it doesn't say what type besides Red Arrow.
I'm sure our CB's had some of the same charictaristics although I'm not claiming to know really what all this means.
Did I Come off a curt on that post about my tyres? I have a habbit if using really short scentances and didn't want to sound that way. Soory about that.
Chris.