Valve extenders for deep section rims

Does anyone have any experience with 100 mm deep section carbon rims, with regards to suitable valve extenders? The longest I can find in most retailers is 65mn, but I'm almost certain these won't be long enough. Can anyone suggest alternatives please?

Could you not pair the extenders with a 60/80mm valve stem?
https://www.wiggle.com/p/lifeline-road-inner-tube

I am using tubular tyres, which usually come with a standard 40mm valve length unfortunately. I actually just found out that Zipp are the only company who makes 100mm extenders, so I have promptly ordered some while I can get hold of them.

Good luck finding a pump head that'll form a decent seal around a Zipp extender. I hate those ones.

IMO* the only ones worth the effort are the ones where you pull out the valve core, insert the extender and then reinstall the core into it.

*My opinion being informed by being the person that everyone comes to at the track when they can't pump their tyres up because they've chosen a shite Zipp extender.

Thanks, hopefully my track pump at home will do the job (it's a Joe Blow track pump). I don't know if there any any alternatives however. I used Challenge extenders on my 58mm rims which were great, but I think they don't make any longer than 60mm.

I actually just found out that Zipp are the only company who makes 100mm extenders,

100mm - https://www.tredz.co.uk/.Token-Valve-Lengthener_237305.htm?
100mm (slightly different design to what I prefer but suspect they'll still work pretty good having a proper core) - https://www.bikester.co.uk/kcnc-presta-core-valve-extenders-100mm-M938904.html
80mm so plus your 40mm valves would be 120mm - https://www.ebay.co.uk/itm/142709302560?

Do you have any plumbers/PTFE tape? Fit some to the valve before installing the extender.

Thanks - I may well consider these if the Zipp ones don't work well!

Yes, I used PTFE tape on my last install and it worked a treat. Thanks! Great tip

IIRC I use 65mm LifeLine extenders installed into Vittoria latex tubes with 55mm or something valve stems.