Guide · Pumps
Presta vs Schrader vs Dunlop: identify your valve before buying a pump
How to tell Presta, Schrader and Dunlop valves apart by the stem, what SV, AV, DV and SCV mean on a tube box, and what to check on a pump head.
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Short answer
Look at the stem before you buy a pump. A thin stem with a small locknut at the tip is Presta. A wider stem like a car tire's is Schrader. A narrow tip sitting over a large locking ring is Dunlop, also called Woods. Then buy a pump whose maker names that valve.
Presta: thin stem, locknut at the tip
Park Tool describes Presta valve stems as nominally 6 mm in diameter, thinner than Schrader stems.[1] The tip has a small locknut. It must be unthreaded before air can enter the tube, and Park Tool's install guide adds a quick tap on the valve to make sure it is not stuck.[2]
Some Presta valves have a removable valve core. Park Tool says you can recognize one by two wrench flats at the end of the valve, and that not all Presta cores are removable.[3] More on that in Presta valve cores that come out with the pump head.
See the Presta valve page for the pumps and tools that fit it.
Schrader: the car-tire valve
Park Tool says Schrader valve stems are approximately 8 mm (5/16 inch) in diameter.[1] There is no locknut to undo. A Schrader-compatible pump fitting presses on the valve's internal stem with a plunger so the tube can fill.[2]
That plunger is why a Presta-only head cannot open a Schrader valve. See the Schrader valve page.
Dunlop (Woods): narrow tip, big locking ring
Park Tool describes the Woods/Dunlop valve as a narrow stem top with a large locking ring beneath it. It says this valve can be inflated with a Presta-compatible head without unthreading the ring, and that it is found on less expensive bikes outside the United States.[1] Park Tool gives no stem diameter for it. See the Dunlop/Woods valve page.
Tube box codes: SV, AV, DV, SCV
Tube boxes often use letters instead of names. Schwalbe uses SV for Sclaverand (Presta), AV for car (Schrader), DV for Dunlop and SCV for its own Clik Valve.[4] Schwalbe says many of its butyl tubes come with Clik Valve, color-coded blue, but its page does not say which pumps work with Clik Valve. Treat Clik Valve as its own system and check the Schwalbe Clik valve page before buying a pump for it.
TPU tubes: check the valve core
TPU tubes use the same valve families, with one catch. Tubolito says its Presta (SV) valve cores are glued in, so only its Schrader (AV) valves have removable cores that accept sealant.[5] That statement covers Tubolito tubes only. See the TPU tube valve page.
Quick reference
| Valve | Stem (Park Tool) | How to open it | Head that takes it (as makers state) |
|---|---|---|---|
| Presta (SV) | Nominally 6 mm | Unthread the tip locknut | A Presta or dual-valve head |
| Schrader (AV) | About 8 mm (5/16 in) | Nothing to undo; the head presses the inner stem | A Schrader or dual-valve head |
| Dunlop/Woods (DV) | Not stated | Leave the ring on | A Presta-compatible head, per Park Tool |
| Clik Valve (SCV) | Not stated | Per Schwalbe's system | Only pumps whose maker names Clik Valve |
What to check on the pump
A pump fits the valves its maker names, nothing more. For example, Lezyne describes its Dual Valve floor-pump head as press-on with a locking lever and compatible with Presta, Dunlop and Schrader valves.[6] The same Lezyne page says its Slip Fit head on hand pumps is Presta-only. Read the valve line on the maker's page, and read how dual-valve pump heads work before you rely on one head for two bikes.
If you ride with both Presta and Schrader tubes, one electric option is below. CYCPLUS says the AS2 Pro switches between Presta and Schrader without extra parts.[7]
Picks that fit1 product
Choose the AS2 Pro, the only variant listed (black). CYCPLUS says it switches between Presta and Schrader without extra parts; it names no Dunlop or Clik Valve support, so check your valve first.
More on choosing
On Amazon, check that 'Ships from / Sold by' shows Amazon.com or CYCPLUS.
Electric pump for a pocket or bag
CYCPLUS AS2 Pro electric mini pump (120 psi, Presta and Schrader)
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Questions
How do I tell Presta from Schrader?
Look at the stem. Park Tool describes Presta stems as nominally 6 mm, with a small locknut at the tip that you unthread before inflating, and Schrader stems as about 8 mm (5/16 in), like a car tire valve.[1]
Is Dunlop the same as Presta?
No. Park Tool describes the Woods/Dunlop valve as a narrow stem top over a large locking ring, a different valve. It also says a Presta-compatible head can inflate it without unthreading the ring.[1]
What do SV and AV mean on a tube box?
Schwalbe uses SV for Sclaverand (Presta), AV for car (Schrader), DV for Dunlop and SCV for its own Clik Valve.[4]
Can I put a Schrader tube in a Presta rim?
We found no source among those we read that covers rim valve-hole sizes for this swap, so we do not give an answer. Ask a bike shop to check your rim before you change valve type.