Still in the 50°s today, so I’m going with the Dixxon Flannel. This one is the SE Racing Edition, as I was a dealer and had a few of their bikes in the past.
The Basic Black tie seems to go best with this one.
Red Kap Trousers, Black Belt, Comfortable Loafers, and it all gets topped off with the Herringbone Tweed Jacket by Bill Blass.