Is Dunlop valve almost the same as Presta?

[On a RoadTrip]

Hi everyone.
First post, posting from a phone while on a week-long bike tour. I forgot to pack a spare mountain bike tube [/w presta valve] and there are not many bike shops around, but we managed to pass by one in a remote area. Surprisingly, they only got Dunlop and Auto valve, no sign of Presta inthe necessary size. Was it a gamble to take Dunlop? Does it usually fit with the same rims as Presta? They look similar ... I prefer google search on my desktop, not on my phone haha.

[Jesper]

(04-19-2021, 05:46 PM)On a RoadTrip Wrote:  Hi everyone.
First post, posting from a phone while on a week-long bike tour. I forgot to pack a spare mountain bike tube [/w presta valve] and there are not many bike shops around, but we managed to pass by one in a remote area. Surprisingly, they only got Dunlop and Auto valve, no sign of Presta in the necessary size. Was it a gamble to take Dunlop? Does it usually fit with the same rims as Presta? They look similar. I prefer google search on my desktop, not on my phone haha.

Welcome "Roadtrip",

You cannot use a Dunlop/Woods valve in a Presta configured rim; has a wider diameter than a Presta valve at the rim hole, but you can use a Presta pump head to inflate it. It will fit a Schrader/auto valve configured rim. You might be surprised at who is carrying Presta valve tubes, but I is still probably hit or miss depending on size and availability. I know Walmart has Presta tubes when they did not a few years back. I am surprised that a bike shop didn't have one unless your rim size is odd.
In a pinch you can "ream" out (on the road: screwdriver, hex wrench, knife, etc.; at home: drill bit) the presta hole making it large enough to fit the wider valve stem. Not too hard to do with an alloy rim when on the road, harder with a steel rim; I wouldn't do it on a carbon rim. Of course now you are stuck using the wider valve stem tubes, but you can still use a Presta tube if the need arose for a quick fix. Personally, I would not alter the rim unless absolutely necessary.