Tubeless is essential in heavily infested goathead territory and is useful everywhere for DAY-RIDERS on fat-tire bicycles (MTBs and touring bikes with wide tires). If you are long-distance touring in remote desert areas, like me, it is a different story, because you will likely be carrying a tiny pump, and even if you are carrying a large primary pump, your spare pump (you are carrying a spare pump, i hope, if you go in remote areas) will be tiny.
[Post edited by Admin. to remove potentially libelous statement about one brand of sealant, made in violation of Thorn Forum Guidelines, posted here: http://thorncyclesforum.co.uk/index.php?topic=26.msg6285#msg6285 -- Dan, Thorn Cycling Forum Administrator]I once experienced a huge puncture with Stans which sprayed the sealant all over the inside of the rim. Washed off easily with a few squirts from my water bottle. I also experienced a tube of Stans leaking at the bottom of my pannier (I now store in the saddle bag). More of a problem to wash off, since it had dried by the time I noticed it, but no major problem. So forget this idea that sealants create a big mess.
Sealants do dry up after a few months, but the dry residue weighs like 5 grams. Not enough to unbalance the tire.
Dan's description of the process involved with prepping a rim for tubeless are needlessly complicated. Get the proper prep kit from Stans, along with the proper and much simpler instructions at Stans website.
Tire liners are a very dumb idea. Heavier than sealant, they WILL eventually destroy your inner tubes, a nuisance to install. Worst of all, they do NOT fully protect from goatheads. Rather, they convert easy to find punctures into slow leaks that are impossible to find without a bucket of water to dunk the inner tube in and look for bubbles. And who has a bucket of water when touring in the middle of nowhere? People who say tire liners saved them from punctures are like people living in London, let's say, who insist that their magic talisman has saved them from being run over by herds of stampeding elephants. Correlation does not prove causation. Punctures are rare if you are using good tires (better Schwalbe tires already contain a kelvar tire liner) and avoid problemmatic areas (infested with goatheads, which are only present in disturbed ground, littered with broken glass and pieces of tiny wire from disintegrated truck tires, etc).
I have a webpage on the subject of protection from goatheads, which also addresses sealants and tubeless and similar topics in more details, including photos:
http://www.frankrevelo.com/hiking/biking_flatprevention.htm.
