Tubeless tires have changed what we can do on a bike. When the terrain is really rough, not having to worry about pinch flats allows us to run lower tire pressure for more comfort, more traction and more speed. (The speed comes from the lower pressure on rough surfaces, not from the tubeless setup itself.)
Setting up tires tubeless can be a hassle – and high-performance tires require more diligence yet. Everything that makes supple tires so fast and comfortable also makes them harder to set up tubeless: The ultra-thin sidewalls aren’t air-tight, and the tires are so floppy that the bead can be hard to seal against the rim. Supple tires need sealant to close those microscopic pores in the casing and to constantly seal the tire against the rim.
There are many tricks to setting up tires tubeless, and the right choice of sealant is one of them. Many sealants are intended for mountain bike tires with stiff casings that are covered with a thick layer of rubber, making them airtight on their own. The sealant is only intended to close small punctures, not to make the tire itself airtight and seal it against the rim. Those sealants can work OK with supple high-performance tires, but we wanted a better solution.
Over the last two years, we’ve worked with Panaracer in Japan to develop a sealant that is specifically formulated for the supple sidewalls of Rene Herse tires. (The sealant works equally well with Panaracer tires and other brands.)
The Seal Smart sealant uses natural latex and walnut shells to make the tire airtight and seal it against the rim. Thanks to these ingredients, it’s non-toxic and low in allergens. Clean-up is easy, too.
Most of all, it works really well. With every tire we’ve set up so far, the tire sealed almost instantly and held its air for weeks without re-inflating. We’ve tried it on tires that were returned under warranty because the sidewall didn’t seal. (This happens very rarely when the rubber coating is a bit too thin.) Bubbles appeared on the casing, and the tires continued to lose air. With the new Seal Smart, two tiny bubbles appeared at first, but the tires sealed fine. We wiped off the bubbles, and they didn’t reappear – the tires were ready to ride.
Of course, every installation is different, and we cannot guarantee a successful tubeless installation. Especially with supple tires, it pays to be extra-diligent when distributing the sealant inside the tire to make sure it goes into every crack. And make sure to shake the sealant vigorously for a minute or more to distribute the solids really well: If you’re just injecting white water into the tire, it won’t seal…
The new Panaracer Seal Smart comes in 500 ml (17 oz) bottles – enough to set up 4-6 tires and replenish your sealant frequently. It is in stock now.