Cushcore Gravel: What I love, what bugs me

Cushcore gravel tire inserts prevent pinch flats and increase cornering stability. They're awesome, but there's one thing that bugs me.

Photo: Brad Kaminski

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If you haven’t heard of Cushcore, it’s probably because you’re not a mountain biker. Only a few years ago, Cushcore all but revolutionized mountain biking with its tire inserts that help prevent pinch flats and add structure to the weakest part of the tire, in turn changing the handling characteristics of the bike for the better.

Now, Cushcore has plenty of competitors in the insert game, largely because the inserts just work; they allow riders to run lower tire pressures for better traction, they all but eliminate pinch flats, and they vastly improve cornering ability.

Not long after Cushcore introduced itself to the mountain bike world, the company grew into the gravel market with its Cushcore Gravel inserts. It’s the same concept as the original, just narrower and lighter to accommodate gravel setups. I’ve been using Cushcore inserts on my mountain bike for a couple of years now, and I spent the last season on Cushcore Gravel inserts on my Trek Checkpoint SL7. They have performed beautifully.

Photo: Brad Kaminski |

What I love: No tire pressure is off-limits to me. I can run my tires as low as I want, and I have even run them with as little as 5 psi (okay, that was just out of the parking lot; but the Cushcore Gravel insert is so supportive that I almost didn’t notice I needed air in the tires).

And pinch flats simply don’t exist anymore. Since I’m a mountain biker at heart, I tend to ride my gravel bike like a mountain bike. I hit rocks harder than I should. I huck off of stuff. I smash into roots. And I rail corners aggressively. The Cushcore Gravel insert has been equal to the task in every situation, and despite feeling the telltale CLUNK of my rim contacting the ground, I still have yet to get a flat.

Yes, Cushcores add weight, but it’s not enough weight to discourage me from using them. To me, the benefits of flat protection, coupled with the increase in grip and control while cornering, are enough to make the weight difference seem negligible.

And they are also pretty difficult to install, but even that doesn’t bother me all that much. Cushcore responded to this problem by designing a burly tool to help you install the insert correctly and easily. I’ve used it recently and it works wonders. Follow the Cushcore website’s directions and you shouldn’t have any problems here.

What bugs me: Alas, there is one thing about the Cushcore Gravel insert — and Cushcores in general — that does drive me a bit mad. The foamy inserts gobble up your tubeless sealant, which means I’ve often come into the garage to get on my bike, only to find the tire has run flat. The usual 2 ounces of sealant per tire isn’t nearly enough; I’ve used up to 10 ounces on particularly stubborn setups.

A CushCore representative said that the product’s closed cell material cannot absorb sealant. The representative said that rim tape and tire pressure are likely explanations for the loss of sealant. 

It is an annoyance for sure. Still, I find the extra sealant a small price to pay for better handling and flat protection. Moreover, the insert helps protect my very expensive rims from damage, so count the peace of mind as part of the sticker price.

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