I have a 2011 street glide. I know tire threads are overdone... with that being said, I would like some feedback from anyone who has had experience with both bias and radial ply tires on a glide. I'm going to be replacing the rear tire. It is cupped and I'm getting some bad shake through high speed turns. Tread life is not a concern, my other bike gets about 5k miles on a rear tire. Some might say I ride aggressively but I wouldn't compare my riding to anything close to the purpose built canyon Carver baggers.
How much of a difference did you notice going from bias to radial in the rear? It seems like the Avon cobra chrome's might be a good choice or possibly the american elites but I think they may only be bias. If the switch is going to be negligible and i get twice as many miles, I'll stick with bias. But if it definitely made a difference in the twisties i will absolutely switch.

I have radials on both ends of my Buell and Sportster, bias front and radial rear on my old Glide (with non-stock wheels). They all ride like 'normal' bikes! I'm not sure what more I can add. If you remove a worn rear tyre and replace it with a brand new one, whether it is identical, another brand, or a different construction, the bike may well feel and behave differently at first, as the new tyre beds in and scrubs off the shiny surface of the tread. Takes a hundred or so miles, by which time your bike is likely to feel normal once more!

How often do you check your tire pressure? What tire pressure are you running?
Bias tires typically have a high load carrying capacity.

Rear tire was at 39.5psi, spec is 40. I wondered the same thing too as I hadn't checked it as recently as I should, but it was still ok.

I'm just curious if anyone has switched from bias to radial. My m109r runs radials front and rear, I have no problem with shake no matter the speed and feel completely comfortable dragging peg at 70+. I know the sg is completely different and don't ride it the same. But if going to radial makes a noticeable difference, I'm game.

Buy tyres recommended for your bike! Most reputable brands make them for our Touring Harleys. If they include radials you're onto a winner! Having checked however, I suspect you will find that most brands will suggest Bias tyres for stock sized wheels.