Gravel; whether it is getting off the beaten track, or following the best in the business as they take on the Life Time Grand Prix, gravel is here and it is here in force. Much more than just the intersection between Road and MTB cycling, gravel sits at the core of adventure cycling and epitomises the DIY ethos like very few sports can.
So how do you set yourself up for success in gravel? Well firstly, we highly recommend going tubeless.
In tubeless wheelsets, the shape of tyre is designed to fit perfectly into the rim wall to create an air-tight seal.​​​​​​​​ Sealant, a liquid, is added to the inside of the tyre which hardens on exposure to air. At inflation, the sealant will be pressurized inside the tyre and, in the event of a puncture, will automatically ​close any leaks in the air-tight seal e.g. punctures. This usually happens instantaneously, allowing you to ride on, rather than having to change your inner tube.
Tubeless wheels have dramatically changed bicycle tyres across all categories, but perhaps the largest gains have been in the off-road segments - gravel or MTB. Previously, a sharp rock, or sudden impact could end your ride. With the advent of tubeless tyres and sealant, both concerns are largely eliminated. However, liquid tyre sealant is not a perfect solution; it has inherent limitations in the size of puncture that may be realistically sealed. For a more in depth look into the pro's and con's you can check out our blog on tubeless vs. clincher tyres here.
For this reason, an entirely new category of tubeless tyre liners has emerged, which offer protection against these large impacts. These liners are an ultralight foam like insert that sits tightly against the rim, with a profile that protrudes slightly above the rim wall. They hold the tyre bead in place and protect your rim from direct impact (from rocks etc.), yet do not inhibit tyre performance or prevent the tubeless casing from deforming, saving your precious watts. Liners are intended to be used with liquid sealant, which still allows them all the benefits of a traditional tubeless set-up.
They're quite expensive compared to just going tubeless, so what's the real benefit? Aside from impact protection, tyre inserts offer benefits when used as a "run-flat" - imagine a thorn piercing the side wall of your tyre and creating a hole beyond the capabilities of the sealant to fix. In a run-flat scenario, the tubeless tyre beads are held in place along the rim walls by the width of the liner, which prevents the tyre from unseating. This allows you to continue to ride with confidence, stopping safely or in some cases, riding home without having to fix your tyre.
Image by  Josh Patterson / Immediate Media (from Bikeradar)
So, you now know how they work, but what about the hard numbers? Well, one of the most popular brands, Cushcore, claim to improve suspension performance by 16% and reduce the impact force from big hits by 50% - protecting your precious rims. They also claim 35% more sidewall stability (allowing you to run lower tyre pressure for better cornering stability and enhanced traction), provide a 12% smoother ride and a 3% reduction in rolling resistance. Can you see why we are big fans of tyre inserts?
As always, if you want more advice on tyre inserts, we'd recommend talking to your local bike shop. Otherwise, get in touch with one of the NSC team and we'll help you out.