Going tubeless

I finally bit the bullet, bought some tubeless tyres (had to buy new tyres anyway) and then heart thumping fitted and inflated them. So, what's the deal?

Tools

You will need:

foot pump

Track pump

Presta -Schraeder valve converter (cost <£1 from local bike shops - not the sort of thing you'll find listed on websites)

Not required - air compressor

This is what you need: Sealant (three of the measures in the red cup per tyre), mix of water/washing up liquid, valve adapter, foot pump, track pump.

Fitting

I used Bontrager wheels that already came with rim strips and tubeless valves. Since I'd been running these wheels tubed for some time, I had to refit the plastic rim strips that I'd taken out. This was not a problem. The tubeless tyres were a little tighter going on the rim than tubed type kevlar beaded tyres and I had to use tyre levers rather than just fingers. That said, it wasn't difficult. Next the bit that's always filled me with dread - inflating them. First off, if you just put a foot pump on them then there's no way they will either inflate or lock onto the rim, they need lubrication. For this you mix up a 25% washing up liquid, 75% water mix and coat the tyres and rim. Fit the foot pump and the beads can now slide on the rim strips, the tyres will inflate but not seal. For sealant I used Stan's, simply because that was what the local bike shop had in. Put the recommended amount of sealant (2 scoops) into the tyre through the valve (tubeless valve cores are removable). Now fit the foot pump and start pumping. You don't have to pump like crazy, just the same as if you were adjusting the pressure on you car. The tyre inflated first time. Incredible. I was fully expecting to have to go down to the garage and use a compressor. There was a little hissing and some bubbles around the rim from the soap but just sloshing the sealant stopped most of this. The tyre wasn't properly seated however, so I switched to a track pump and cranked it up to 60 psi. There were a few frightening pops and bangs as the bead suddenly seated correctly and all bubbling stopped.

Now the second tyre. This didn't go quite as smoothly as there was a leak around the valve. I had to refit it and then really crank down on the lock ring with pliers to get the o-ring seal to compress. The tyre then inflated just the same as the first.

I left both tyres overnight with 60 psi in. Come morning one had lost 10 psi, the other was still holding 60. I reduced them to something more sensible and went out for a ride. The hedges alongside a bridleway had recently been cut and so there were bits of branch and thorn everywhere. Its a fair bet the tyres punctured (no way of knowing for certain though) but the sealant did its job and no loss of pressure at all.

One thing I will add is that at no time did the tyres spray sealant every where. There was a little leakage putting it in the tyres through the valve stem but that was easily wiped up with a rag. Overall, it wasn't messy.

Three weeks after fitting the tubeless tyres, they have not lost any pressure.

Advantages/Disadvantages

There's no disputing the fact that fitting tubeless tyres is more difficult than fitting tubed tyres. That said, although it turned out to be fairly easy, that was in my garage. Re-fitting on the trail is a definite no-go. If they do lose pressure then you'll have to fit a tube to get you home.

Tubeless tyres are currently a lot more expensive than tubed tyres, however, factor in a tube and they come a lot closer but tubeless is still slightly more expensive. Then add sealant. This is a must. A bottle of Stan's costs £15 but I used less than a quarter of it to fit two tyres.

Weight. As you will see below from my own measurements, there's nothing in it.

Lower pressures. I ride cross country not downhill and pinch punctures aren't a problem. In muddy conditions I'll run 15 psi in the front and 20 psi in the rear just to get traction. I can't go lower than this as the bike handles like a complete dog on the road with the tyres that soft. So, for me, being able to run lower pressures isn't an issue.

Lower rolling resistance is often claimed as a tubeless advantage. I can't comment on this, however, any advantage will be small and will be completely swamped by a dragging brake pad.

Puncture resistance. As I've already said, I run slimed tubes as thorn punctures are a big problem for me. I also find that slimed tubes are far from perfect and some brands are better than others. Personally I find the kosher "Slime" brand by far the best and Bontrager self sealing tubes to be pretty poor. Theoretically it should be much easier to seal a punctured tyre than a punctured tube as the rubber is much thicker and the membrane stresses correspondingly lower. It is for this reason alone that I've gone down the tubeless route. Only time will tell if tubeless does indeed live up to the hype.

Weight

One of the oft cited advantages of tubeless tyres is a reduction in weight and if there's one component of a bike that can use a weight reduction its rims and tyres. If you have extra weight on say the bike's frame then you have to put in extra effort when pedalling up hill. However, because the wheels rotate, as well as their mass, there is also inertia to consider. Inertia is the product of mass and the radius squared (from the centre of rotation). The worst possible place you can add extra mass to a wheel is the rim/tyre as its at the greatest radius from the axle. A 1kg increase in hub mass won't have any where near the same effect on a bike's responsiveness as a 1kg increase in weight on the tyre/rim. So any weight reduction offered by going tubeless is a great advantage.

Here's some actual masses of a somewhat random collection of wheels, tyres and tubes.

Cheap wheel + Kenda tyre+ slimed tube - front	2.5 kg
Cheap wheel + Kenda tyre+ slimed tube - rear	3.2 kg
Bontrager wheel + Jones ACX tyre + slimed tube - front	2.0 kg
Bontrager wheel + Jones ACX tyre + slimed tube - rear	2.6 kg
Bontrager wheel + Jones Mud X tubeless tyre and sealant - front	1.9 kg
Bontrager wheel + Jones Mud X tubeless tyre and sealant - rear	2.4 kg
2x Kenda tyres	1.75 kg
2x Bontrager Jones ACX tyres (actual weight)	1.25 kg
2 x Bontrager Mud X tubeless tyres (claimed weight)	1.1 kg
Bontrager race disc wheels (no tyres)	2.75 kg
Cheap wheels (no tyres)	3.4 kg
4 x slimed tubes	1.5 kg
2 x non-slimed tubes	0.4 kg
2x Bontrager Satellite elite 26x1.5 hardcase semi-slicks	1.4 kg

As you can see, the tubeless set up is lighter than a slimed tube set up but heavier than a normal tube set up. Where I live in the south of England, slimed tubes are a big bonus as you tend to get lots of thorn punctures. In this situation there is a small weight saving in going tubeless. What is obvious though is that if weight is important then bin the wheels that came with a £700 bike and get lighter ones, the weight saving is far far greater than you'll ever get by going tubeless.

Note that there is no discernable difference between the Bontrager Jones ACX tyre and the Bontrager Jones Mud X tyre.

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