Modern Radial Tires

Hi I am putting Metzeler Z6 radials on my kz900 170/60/17 on the rear and 110/80/18 front, has anybody tried this combo or anything close to it? So called experts say not to run radials on these older bikes,but I think this is bogus I am ordering these tires monday.Any input would help, this could be a costly experiment! Thanks ZTorch

as long as you have the right width wheels and a swing arm wide enough for the tire you will be fine.new radial tires on a old bike work great.heres a pic of my kz1000 with a 180 rear.

depending on which bike youre working on id say the biggest issue is going to be swingarm flex and frame bracing,im guessing youve already dealt with the swingarm issue.