Which Tubs?

Sunday in Büttgen, the track was a lot older, maybe ore slippery surface, but (maybe important to point out) no heating. Temperature was around 3 - 5 °C.
Still a lot of riders on the track without any grip problems, riding around with moderate speed, chatting with the hands on the drops, etc.

as i'm only riding in the winter months at our "local" indoor velodrome (80km away) which always has less then 5°C i never ever had any issues with grip. it's an old wooden velodrome (200m length, 45°, appr. 4m heigh) and i'm riding a conti tempo II at the back and a conti sprinter at the front. but there are also guys who riding clincher tires without any problems, mostly with a minimum of 145 psi/10 bar.