
After using Avon - Grand Prix & Road Runners, & Dunlop TT 100 I have been using a Heidenau 3.50 x 19 rear tyre for some 2600 miles.
So far so good, it is a good quality tyre, red spot for balance and directional with load rating and speed rating in excess of a twins requirements.
It is a little 'Blocky' compared with more modern tyre patterns but suits my Vincent fine. It is far better than the 4.10 H19 TT100 for 'whitelining' and the profile is excellent. The bike goes from one bank to the other very smoothly. When I fitted it it went on quite well despite being a very firm carcase.
At about the same time I fitted a 80/90 -21 Pirelli MT66 to the front instead of an Avon 3.00 x21 Speedmaster. Again an improvement, no noticeable loss of steering stability that is so good on the Avon Speedmaster, so the above make a good combination for a solo Vincent.