Any reason NOT to go MTB tubeless?

[jackthelad]

I went for a ride with the OP
he gave me a lift for a ride
and i will happily help him go tubeless
when he has the valves and sealants.
i have everything else to go tubeless
compressors and tapes etc.

His old bike bike was a15 yr old 26 HT, with V Brakes,
so he's had a steep learning curve, after cracking his headtube
dealing with new wheelsizes, Tyres, shocks and disc brakes.

[Duck!]

Don't take it personally, but this one covers most of the myths, so I'll rip into this one. Most of it is bull; my debinkings in red

So....are there any reasons why would you NOT want to go tubeless for MTB?

sealant dries out OK yeah, but it takes six months or more. How many flats might you have fixed in that time?
everything costs more Bull. Tubeless tyres cost about the same as good foldies. Sufficient sealant costs about the same as a pair of tubes (and lasts longer), valves (if not supplied with the rims) cost about the same as a pair of tubes, and last a bloody sight longer. So in the long run tubeless costs less.
tyres are harder to get on and off the rims Depends a hell of a lot on tyre and rim combination; no different to non-tubeless. Some combinations will be a pain even with a compressor; others will be fine with a mini-pump; others will fall in between. I've dealt with them all.
you still need a tube to fix a big tear Yes, that at least is true. But you'd still have to carry a spare tube anyway, so what's the differece?
sealant slops around in the tyre Bull. G-force from the rotation of the wheels spreads what hasn't soaked in around the tyre, so it's no different to having a tube in there.
tubulars are lighter & faster and can handle even lower pressures without pinchflats Tubulars in MTB are extremely rare, expensive, and not in the context of the original question. Tubulars still have a tube inside the tyre, so are not immune to pinch flats; therefore claims of ability to run lower pressure than tubeless are highly dubious. Plus they're a royal pain to fix on the fly unless you happen to be carrying a pre-glued spare tyre with you..... In any case I'd take tubeless over tubular in half a heartbeat, maybe even faster.
sealant is almost as messy as tubular glue In both cases, only if youdon't know what you're doing, but even when you do, glue is a fair bit messier Adding sealant is a very clean process.

The short answer is that no, there is no good reason to NOT go tubeless on MTB

vs
ghetto tubeless is cheap True, and easy BUT can be more sensitive to rim/tyre fit
tubeless + sealant rocks bigtime when you're in double-gee/caltrop territory Doeasn't matter where you are, tubeless just plain rocks!

[Jmuzz]

Do tubulars still have tubes inside?
I have been assuming that the newer varieties are probably just a permanently sealed construction, no stitching a tube in there.
A lot of the diagrams certainly make it look that way.

[singlespeedscott]

They still have an inner tube. The top quality ones use a latex tube.

[Thoglette]

Don't take it personally,

Haven't, wouldn't. Good to have you chip in.

They still have an inner tube. The top quality ones use a latex tube.

Some mftrs are doing "tubeless" tubulars.

The ones I've been able to afford are "meh" and I'll not bother again. Basically, they are are a one piece molding and feel like it. I could imagine that a conventionally constructed (i.e. hand made) tubular with a squirt of "magic juice" rather than a tube might work.