Simply Cycling 27 Inch x 1.25 Inner Tube with Presta Valve

Simply Cycling CC013 Inner Tube, 27 x 1.25, Presta Valve27 inch is an older road wheel size, common on classic road bikes and vintage bicycles built before 700c became the standard fitment. It is not the same size as 27.5 inch, a modern mountain bike wheel with a smaller diameter, so the two are not interchangeable even though the names look similar. This tube is built for genuine 27 inch wheels only. The 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 tube has a Presta valve, the narrower type with a screw-down top and a locknut, sometimes called a French valve. 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 o