How To Tell What Size Valve Stem I Need

It is easy to overlook the apprehensive valve stem, just should it fail, or worse, be also short to suit your wheels, and so information technology tin sabotage your entire ride. In this mail, Australian tech editor Matt Wikstrom takes a look at one of the most little but important parts of your bicycle.

---

Once upon a time — let's say in the '80s — in that location was no need to worry about the length of the valve stalk when buying a spare tube for your road wheel. Low-profile box section rims were ubiquitous and a single valve stem length, ~40mm, could serve every road bike.

All of that changed with the introduction of high-profile aerodynamic rims, and more recently, the massive growth in composite rim designs. Now local agglomeration rides are populated by wheels with rims ranging in tiptop from ~25mm to 60mm or more than.

Such variation is a cause for confusion when information technology comes to buying a spare tube, peculiarly for the uninitiated. In most cases, calculation 15mm to the meridian of the rim is a reasonable rule of thumb when it comes to deciding on a valve length. That extra 15mm is important because it provides enough length to fit any pump caput.

Valves come up in a couple of unlike configurations and it's possible to extend them to conform different rim profiles.

According to this rule of thumb, low-profile rims that mensurate around 25mm crave a 40mm valve stem. For those wheelsets measuring 35-45mm, a 60mm valve stem will normally be long enough, while anything taller than 50mm demands an 80mm valve stalk.

Valve stem length	Maximum rim height	Examples
40mm	25mm	Shimano C24, Mavic Ksyrium, HED Ardennes, Zipp 202
50mm	35mm	Fulcrum Racing Null/1/iii/5/7, Shimano C35, Campagnolo Scirocco/Zonda/Eurus
60mm	45mm	Mavic Cosmic forty, Zipp 303, Enve 3.4
80mm	65mm	Shimano C50, Mavic Cosmic 60, Zipp 404, Enve v.six

For those riders making use of very high-profile rims similar Zipp'due south 808, a valve extender will usually be necessary since tubes with very long valve stems are rare.

There are ii kinds of valve extenders: at that place are those that thread onto the valve stalk simply similar the valve cap, and then there are those that thread into the valve stem. For the latter, the valve must have a removable cadre, and so won't be compatible with all tubes (Continental and Schwalbe tubes typically have removable cores, bargain brands do non).

Of the two, the second strategy is far more robust, since the extension is less likely to leak and more than probable to work accurately with the pressure level estimate on a pump. And since the valve is situated at the elevation of the valve stalk, it's much easier to deflate the tyre.

Making use of valve extenders

For those that haven't had much experience with valve extenders, hither'due south a quick overview of everything that you lot'll need to know:

one. Know your valve extenders. A valve extender tin can thread onto the valve stalk like a valve cap (left), or information technology can thread into the valve stem in place of the core with the aid of a small tool (right).

2. Know your valves. Picking the difference between a valve stem that has a removable core or not can exist hard, however removable cores ever have flattened sides on the upper thread, every bit tin exist seen for the lower stem in this photo.

3. Go the right tool. It may look insignificant, simply this small plastic tool is all you'll need to remove the core of a presta valve. Simply fit it over the upper threads and unwind it similar a grit cap.

4. Recall the possibilities. For those extenders that thread onto the stem, just one can be used to lengthen the valve stalk, while the alternative can exist stacked.

Last considerations

Every road passenger should be cocky-reliant, so with the rim tiptop in mind it should be a simple matter for any rider to equip themselves with suitable valves. All the same, for those riders that participate in bunch rides, or join a regular group of friends for a ride on the weekend, it's worth carrying a tube with a valve stem that volition adjust everybody's wheels.

Punctures always happen, and then rather than get out somebody with tall hoops stranded on the side of the road, carry a tube with a longer valve stem. Improve withal, make certain information technology has a removable valve core so that a valve extension tin exist used if necessary.

As for those riders that ride on high-profile wheels, it's worth keeping an extra valve extension (or two, one of each kind) in your saddlebag or bailiwick of jersey pocket along with a cadre removal tool. In this way, yous should be able to catechumen whatsoever valve stem to conform your wheels.

Finally, valve extender can develop leaks after repeated use, but there's an easy ready: merely wrap some plumbers tape effectually the threads (in an anti-clockwise direction so information technology won't unwrap every bit the extender is tightened) and that will restore closed seal.

Tags

How To Tell What Size Valve Stem I Need,

Source: https://cyclingtips.com/2017/02/spare-thought-valve-stems-everything-need-know/#:~:text=According%20to%20this%20rule%20of,demands%20an%2080mm%20valve%20stem.

Posted by: pittmanhavess82.blogspot.com

Share this post