Tubeless Woes

First off, start with a clean rim bed and by clean I mean wipe with a damp cloth, getting into the bead and then wipe with some IPA. This will give the rim tape the best possible surface to stick to.

If the centre channel is really deep I usually build it up with some insulation tape first. Then wipe the insulation tape with some IPA. 

Get some Tesa 4289 tape. This is basically what every tubeless tape is but you can get a huge roll for a few quid. If the internal rim width is 20mm I usually use 21-22mm width tape. This means the tape will be under the tyre on the bead. If the tape isn't wide enough and the tape hasn't stuck properly air will find a way under and the tubeless sealant will actually help to lift the tape.

When fitting the tape I put the wheel on a chair so I can work from above and trap the wheel as I apply the tape and making sure there are no bubbles under it. Once you've  applied the tape go round with a clean cloth and make sure it's stuck down, especially at the bead.

Use a toothpick, something round and sharp to create the valve hole but not too big. Push the valve through the hole and let that make the hole fit it. Don't screw the valve down too tight just yet as this means the tyre will have the fit around a wider part of it.

I usually let the tyres sit in some warm-ish soapy water then the beads are nice and pliable. The soapy water helps the tyre slip up on to the rim bead.

Work from the opposite end of the valve towards it. Make sure the tyre is in the centre channel all the way around, especially near the valve.

By now, all of the above should mean the tyre will inflate with just a track pump. If it doesn't then I sometimes use a co2 cartridge.

Once the tyre is seated, leave it for 10-20 mintues. After 10 minutes, let the air out, the tyre shouldn't slip in to the centre channel. Remove the valve core and apply the sealant. I re-use the little bottles you get some sealants in that fit over the valve stem or you can get a medical syringe. Once the sealant is in the tyre, the valve core fitted and the tyre inflated you need to make sure the sealant gets everywhere inside the tyre and rim. Not just a gentle spin or a ride. You need to systematically shake the wheel as you rotate it. Both sides. I can't stress how important this part is as it will get the sealant everywhere.

I love doing tubeless tyres, it's my thing 😀

A fine and very comprehensive answer.

This man knows what he is talking about. I would add that if you use CO2 to pump up your tyres, they will lose pressure more quickly than if you had used air from a track pump. CO2 permeates through rubber more quickly than air, even though CO2 molecules are larger than nitrogen and oxygen molecules, CO2 is soluble in rubber and so passes through it quicker than air. So once your tyres are seated, deflate them, inject your sealant and then pump back up with a track pump. I persevered with Muc-Off sealant in my 28mm Hutchinsons at 60 psi but found it didn't live up to  it's "no puncture hassles" claim. Basically it was shite sealant, tyres would lose a lot of air over a week, which I thought was normal for tubeless tyres but when it failed to seal a small thorn puncture  I switched to Stans and boy what a difference. My tyres now lose much less air.

"I would add that if you use CO2 to pump up your tyres, they will lose pressure more quickly than if you had used air from a track pump."

Really?  That is not my experience, I have been using CO2 canisters for roadside repairs (inner tubes and tubeless before I went back to inner tubes because of all the fuss and no noticable improvement) for 10 years and have not found my tyres deflating or needing topping up any quicker than using compressed air from a pump, they can last months before they need topping up.  I believe this "fact" about CO2 seeping out to be a myth.

I don't know if CO2 leaks through tyres quicker than air, but one issue can be that very cold CO2 can cause polymerisation of the sealant which could then affect your tyre's permeability. If you ensure that the valve is at the top of the wheel when using CO2 then it should warm a bit before hitting the sealant pooled at the bottom.

Just found this bit on the bike pump Wikipedia page (https://en.wikipedia.org/wiki/Bicycle_pump):

Quote:

Carbon dioxide leaks out of a rubber inner tube more rapidly than air - despite its larger molecule size, the CO2 molecule is significantly more soluble than Oxygen and Nitrogen in rubber and as such can cause a tire to deflate far quicker than if filled with air.

That's mentioning an inner tube, so it's possible that there's a similar mechanism with leaking through tubeless tyres, although they're not just rubber.

I'd nitpick on the building up the centre channel. It is likely that the deep centre channel has in part been designed to make it feasible to fit some tyres.

Tubeless should be fitted without tyre levers as the levers can damage the edge of the tyre, causing sealing failures. To fit a tight tyre, tubed or tubeless, the starting point is to ensure that the tyre is located in the channel. Get this right and many of the most infamous tyres can be fitted by hand. I've fitted Continental 5000TLs to my Giant without issue and Schwalbe 1s, and the Giant own brand are easy enough too.

In my repair days I was faced with an impossible tyre. Removing 3 of the rim tapes fixed that one!

I've only ever used tubeless ready wheels though so have never been through the pain of applying rim tape for tubeless.