Simply Cycling 700 x 18-23c Inner Tube with Presta Valve

Simply Cycling CC012 Inner Tube, 700 x 18-23c, Presta ValveSeven hundred c is the standard road bike wheel size, and this tube covers the narrower end of it: tyres from 18 to 23mm wide. That takes in classic road bikes, track bikes and any build still running the 23mm tyres that were standard racing fitment for years. Simply Cycling Inner Tube is made from butyl rubber and air leakage tested, so it holds pressure between rides.Which valve do I need?This is the Presta version, the narrower valve fitted to almost every road bike. It is sometimes called a French valve, and it needs a pump head suited to Presta, though most modern track pumps switch between the two.The way to check is to look at the old tube or the hole in the rim. A Presta valve is narrower, around 6mm, with a small nut on top that unscrews to let air in. A Schrader valve is wider, about 8mm, with a small pin in the centre and a threaded outer sleeve, the same type used on car tyres. The rim hole matters most: a Presta va