The more miles you do the greater your chance of a puncture. Glass on city streets to foliage in the countryside, it's always best to be equipped for repairs on the road. The best way to avoid punctures is to keep your tyres inflated to 80-100 PSI. However, if you carry the Brompton Toolkit and a spare inner tube, you will have everything you need to fix a puncture on the road. Please Note: T Line bikes have a Presta valve tube. A Schrader valve will not work with T Line. Presta valve tubes are not recommended for use with other Brompton bikes.