Fair do's to Uniroyal, they got back to me asking about the Rainsport pressures and only 2 days after I sent the email! "Thank you for your recent query. Pressures for track use a very much a personal decision. It is not uncommon for pressures to be dropped given the forces involved which invariably leads to expansion after several laps. The Uniroyal's are quite pressure sensitive, so it pays to be very accurate with regards to how you set them. In addition, they have quite a deep tread depth from new so pressure becomes even more critical as too low a pressure will lead to excessive block movement which can affect handling. Will you be driving to the circuit on the tyres? The pressures will need to be adjusted when they are stone cold so this would need to be done prior to leaving. How they react on the day will be down to the ambient temperature, track temperature and how hard you are pushing them. It will not be uncommon to see an increase of up to 10psi after several laps in warmer temperatures - particularly on such a short and technical circuit where braking and cornering forces are frequent and can be quite severe, depending on your ability and knowledge of the circuit of course. As such, you need to be very mindful if you are adjusting them when warm/hot to compensate for what handling issues you may find. Ultimately, you have to experiment to find the best pressures that work for you. Best regards, Craig Product Support Engineer"