Tyres tyres tyres! Aero tyres, big fat gravel tyres - in this episode has a lot of tyres in it. We have a bit of a shakeup this week. Dave Rome is on a well-deserved holiday so Caley and Ronan are joined by pro mechanic Zach Edwards to talk through Parcours' latest tyre testing and what the data can teach us about optimising for various road courses. Then we discuss the trend toward 50mm+ rubber at the pointy end of gravel races, some updates from Zwift, and Caley's new cross-country bike.