So, my fat bike has come from the dealer set up as tubeless. Getting it out of the garage for a pre- gravel dash fettle I find I have a flat front tyre

Having removed the valve core there is, as expected, no sign of sealant.

I'd rather not break the head of the tyre as I'd struggle to get enough air in to reseat it, so as a newbie to tubeless:

Can I just add sealant via the coreless valve and give it a spin and a shake to distribute the sealant?

How much fluid for a 4.8 inch fat tyre?

And thanks to Big Dummy Steve for giving me a nifty valve core removal tool on the WRT it works well

Yes, you can add sealant through the valve once the core is removed. You'll need a fair bit for a fat tyre. I use the stans injector to top up my sealant.

150-200 ml for a fat tyre, squirt seal is better than stans

Worth finding out what sealant was in there originally and use the same stuff. The rumour mill says it’s not good to mix them but not had first hand experience of this

It is a very good idea to carry a tubeless repair kit too.

Weldlite etc do them and they work well, takes a few goes to get it down pat mind.

If you are feeling flush then Dynoplug are bloody brilliant.

If you go to a chemist and ask them for a 50p syringe 20ml, you will find that the plastic end of this fits perfectly inside the core of a presta valve, once core is removed, so you can add sealant precisely.
Rinse the syringe after if you want to use it again as I've found the sealant residue left over time has rotted/melted the plastic of the syringe.

While tubeless is generally less hassle than tubed what you are really doing is moving the hassle from the trail to the workshop. If/when things go wrong out on the trail it tends to be a bit more dramatic than with tubed (and of course it will happen at the most inopportune moment at the worst possible location) so having a backup is sensible. I put a split in the central running surface of a tyre at the JennRide, even fresh sealant wouldn't deal with it, fortunately it wasn't a new tyre.

I'd take:
Spare inner tube. Remember to carefully check the inside of the tyre for thorns before using!
Tyre boot - can be a bit of old inner tube
Needle and thread - to repair sidewall splits, a curved needle makes the job easier with the tyre still mounted (I'm sure Gian will be along with his Icelandic repair story )
Sealant - 50ml should be enough for normal tyres but you might want more for fat ones.
Normal tube repair kit - with fresh glue
Tyre plugs (anchovies) - to plug larger holes such as from 6" nails and then let the sealant do it's job.
Core remover or pliers.
Zip ties - can help hold a tyre on. You won't be riding quickly but you will be able to keep moving.

If you've an old tyre lying around or one that you are about to bin it's worth having a practice at home

While tubeless is generally less hassle

The only real hassle with running tubes is tubeless zealots at café stops asking you if you are running tubeless and then droning on about it. Happened to me 3 times in the highlands last week

restlessnative wrote:

While tubeless is generally less hassle

The only real hassle with running tubes is tubeless zealots at café stops asking you if you are running tubeless and then droning on about it. Happened to me 3 times in the highlands last week

So are you running tubeless then?

I came across this about tubeless repairs http://www.bikepacking.net/forum/questi ... ll-repair/ Note that the link in the first post no longer works.

restlessnative wrote:

While tubeless is generally less hassle

The only real hassle with running tubes is tubeless zealots at café stops asking you if you are running tubeless and then droning on about it. Happened to me 3 times in the highlands last week

The only real hassle with tubeless is tube zealots droning on about how they haven't had a puncture in years and/or that their friend suffered a horrific injury because their tubeless tyre fell off.

johnnystorm wrote: The only real hassle with tubeless is tube zealots droning on about how they haven't had a puncture in years and/or that their friend suffered a horrific injury because their tubeless tyre fell off.

Thanks all.

I got a big and a small bottle of stan's (as that's the brand that was in stock). I plan to use the small bottle to dispense the sealant into the tyre via the valve. There's not been sealant in the tyre before so mixing brands is no issue.

If that fails when I try tomorrow, I'll get a syringe from my local chemists.

I always carry a spare tube, a tyre boot and zip ties. I'll add the small bottle of sealant to my kit and look into the repair kits.

A belated update. On a stony downhill, on the Dorset gravel dash, I heard a hissing sound from the front tyre, and despite my best efforts of spinning and wiggling the wheel the sealant didn't seal. So after a bit of faffing, I decided to fit my spare inner tube. To my surprise there was an inner tube already inside the font tyre!

The tubeless (but sealant free) set-up from the dealer wasn't! It hadn't occurred to me to check, before I added the sealant.

The sealant had done a good job of trying to seal the tube, but hadn't quite worked.

Time for some new tubeless valves and some (more) sealant!

(Sorry)

Happens a lot! Tubeless ready on the spec sheet doesn’t mean it’s tubeless done. Had a few customers query this

Something I learnt about tubeless recently (and the reason why I've fought with my tyre/rim combo for years)...UST and TCS are barely, if at all, compatible. Was chatting with a bloke from a bike shop on XWA and he explained to me the hook/bead interface is slightly different for the two different types. No doubt someone from these parts will be able to clarify/confirm/deny any of this - I'm just a casual bystander.

Greetz

S.

voodoo_simon wrote:Happens a lot! Tubeless ready on the spec sheet doesn’t mean it’s tubeless done. Had a few customers query this

I didn't think to query as it said 'tubeless' not 'tubeless ready'!

Clearly I'm far too trusting

Dr Nick wrote:A belated update. On a stony downhill, on the Dorset gravel dash, I heard a hissing sound from the front tyre, and despite my best efforts of spinning and wiggling the wheel the sealant didn't seal. So after a bit of faffing, I decided to fit my spare inner tube. To my surprise there was an inner tube already inside the font tyre!

The tubeless (but sealant free) set-up from the dealer wasn't! It hadn't occurred to me to check, before I added the sealant.

The sealant had done a good job of trying to seal the tube, but hadn't quite worked.

Time for some new tubeless valves and some (more) sealant!

I've tried various sealants in inner tubes, it just doesn't work anywhere near as well as straight up tubeless in my experience. Stanimals seem to form pretty instantly too.