Latex tubes typically only come with 42mm valves.

do you know the model? that might help also if you have the wheel in hand then it is easy, otherwise if not then you need to look for 2 options buy any tube you want and get some valve extenders or buy long stem valves, Vittoria butyl longest is 80mm, same for Schwalbe so depending how deep the wheel is you may still need a valve extender.

The valve stem needs to be roughly 15mm longer than the wheel depth. Rim beads vary, so this is an approximation, but a fairly safe one.

Personally, I use valve extenders on all my deep wheels (the older "straw" kind where you don't move the valve core) for the following reasons:

-You can buy any length stem tube (or borrow any length stem tube from a riding buddy if you flat).

-Latex tubes mostly come in 40mm, so you'll need extenders to run them.

-If you run a deep wheel front/disc rear combo in a race you typically need a short valve stem tube for the disc.

-If you get a different depth wheel in the future, your stock of tubes isn't obsolete.

-Extenders come in a variety of colors, so you can bling out your bike with ones that match the frame or decals. Yes, this is a very minor point, but if you are going to get extenders anyway...why not?

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Only Silca. Challenge is 47.5mm, Vittoria is 48mm, Vresdestein is 50mm.