Thursday 2 March 2017

Going tubeless

I was an early convert and switched to tubeless tyres on my mountain bike many years ago. There is no way I would go back! Occasionally I ride a bike with tubes and the lack of control, feel and grip will be one of the first things I notice.

Replacing the tube with sealant allows you to run lower tyre pressures. At the Gorrick race on Sunday I ran 18psi front and 21psi rear which is the softest I've tried. However, on the fast rooty course it worked perfectly, taking the sting out of the multiple impacts. On the damp soil it also increased the tyre surface area in contact with the ground providing extra grip for cornering up front and increased traction on greasy climbs on the back wheel.You are able to risk running those much lower pressure because there is no chance of pinch flatting a tube against the rim.

So you might think that rolling resistance would go up at such low pressures, but because the tyre is more supple and absorbs small undulations in the trail you actually roll along faster and in much more comfort too.

The big sales pitch behind tubeless tyres is of course their puncture resistance. On YouTube you can watch video's of people stabbing hundreds of nails into tyres or riding over beds of spikes. I have taken off tubeless tyres which when I've checked have had 4 or 5 thorns in them that would have deflated a tube in seconds. So it undoubtedly works! Living on the South Downs one of the main causes for punctures is cuts from flints. This is an area where tubeless sealant isn't always quite so successful. Cuts tend to open and close under stress as the tyre rotates. This means that the hole can continue to weep slowly, sometimes covering rider and bike in a splatter of latex sealant. There is also no doubt that when something does go wrong out on the trail, putting in a replacement tube can be a very messy business!

The same can be said when it comes to fitting tubeless tyres. With a pump it can sometimes be frustrating (and tiring) trying to get in enough air to get the bead to seal allowing the tyre to inflate. However there are some great high volume pumps on the market now which overcome this problem by dumping a volume of air instantaneously. For example the Top Peak Joe Blow Booster.

The final advantage of tubeless tyres is the weight saving. It is relatively small but that weight is in a critical area - rotational mass. So you'll be able to accelerate faster.


I've tried various brands of tubeless sealant but have always come back to the original - Stans No Tubes. They have recently released a Race Sealant which claims to have larger particles floating around in the liquid that seal the hole quicker. This is a claim that is hard to verify as no two punctures are the same, but the peace of mind probably justifies the higher cost.

No comments:

Post a Comment