This article will help new cyclists to properly recognize the two most widely used bicycle inner tube valve systems. New cyclists are frequently bombarded with choices they are unfamiliar with when purchasing or replacing bicycle inner tubes. This sometimes leads them to purchase the correct size tube (in length and width) with the incorrect valve type, or to attempt to install an improper inner tube valve into a rim hole that is either too small or too large for the valve type they have chosen.
NOTE: The larger Schrader valve tube will not fit into the small rim hole designed for a Presta valve tube. However, a Presta valve tube will fit into the larger rim hole designed for a Schrader valve tube but doing so will greatly increase the chance of tube failure from a pinch or tear near the base of the valve stem.
Photo 1 – Schrader / American Valve (You will see this notated on the inner tube box as SV or AV).
These type of valves are used with rims that have a larger valve hole.
Photo 2 & 3 – Presta / French Valve (You will see this notated on the inner tube box as PV or FV)
These type of valves come in either threaded or smooth post style. These type of valves are used with rims that have a smaller valve hole. Most wheels utilize the threaded post style. The threaded post style utilizes a fastening nut which holds the valve in place against the rim (Photo 2). The smooth post style (seen on the right in Photo 3) is longer than the threaded post style and is primarily used with rims that have a very deep wall design (i.e. Triathlon disc, carbon fiber, and special application wheels).
So WTF does the SV stand for??
SV = Schrader Valve. SV is also sometimes recognized as being AV = American Valve.