Nex-Gen is a company that you may not be familiar with, but if you take a glance at their site, you’ll see the company has big plans for the cycling world. Handlebars, chain lube, 3-D printed saddles, and much more are on the “Coming Soon” side. Their new Ultra Sealant, “a custom synthetic off-road sealant specifically formulated for high volume, low-pressure tires,” is the company’s solution for tubeless tires. The idea sounds great, but what is it, and how can it claim to be better than the existing solutions?

Nex-Gen Ultra Sealant bottle site

Ultra-Sealant: What does this mean?

The description is pretty vague, but the tech docs claim the new Nex-Gen sealant can seal up holes up to 6mm — that’s solid for sure. Another very promising claim is the climate range of the sealant. Nex-Gen states the Ultra-Sealant stays active and does its job in temperature ranges from -15°C <> 80°C / -5°F <> 176°F, with a shelf life of greater than 12 months.

Nex-Gen Ultra Sealant bottle close up

What’s the formula?

Much like anyone in the chemical world, Nex-Gen isn’t giving out the secret recipe, but the company states in its marketing, “why do sealant brands expect you to use decades-old latex sealants?” Making us wonder if this is a latex-based sealant with an updated formula or something new, along the lines of the Finish Line Sealant.

Nex-Gen Ultra Sealant bottle back side

The super long shelf life supports the idea of non-latex based. The difference being latex sealants use the natural coagulation properties of the compound to stop punctures. The latex coats the area after many passes, and the air escaping stops — it works well, which is why most sealants are latex-based.

Nex-Gen Ultra Sealant bottle big refiller

Non-latex-based sealants require no change to occur within the tire; these sealants have larger particles that can physically plug the puncture without the aid of latex as a binder. This non-active ingredient (for lack of a better term) gives the non-latex options a much better shelf life but results in less optimal sealing power in our past experience.

Nex-Gen Ultra Sealant bottle

Nex-Gen also states this is a high-volume, low-pressure sealant meant for mountain bikes, fat bikes, and anything running something wider than a drop bar. So, does that rule it out or make it less practical for use on the road? We’re guessing no, as many sealants previously were formulated for “off-road use” and eventually saw tarmac-time. Though the industry is quickly coming up with solutions to road tubeless and high-pressure specific sealants are on the market like Specialized’ Rapid Air sealant.

Availability and pricing

The Nex-Gen Ultra-Sealant is available for purchase on the company’s website, along with other gear to outfit and clean your bike. The going rate for Ultra-Sealant is $14 for a 150ml and $30 for a 500ml pack. Nex-Gen suggests on their site that 150ml of Ultra-Sealant will provide adequate protection to a singular fat bike tire.

Long term environmental impact

Nex-Gen also states the new Ultra-Sealant is 100% toxin-free and is safe to use in any environment. Many sealants make this claim, so the real question is — does it work? Some sealants like Rene Herse/Panaracer go as far as to use ground-up walnut shells to ensure the environmental responsibility of their sealant. Yet, without comment from Nex-Gen, we can’t verify the environmental impact of its sealant, though the claims sound promising.

Nex-Gen Ultra Sealant bottle tubeless tool attached

Does it work as claimed?

We’ve reached out to Nex-Gen for some samples to put up against the bike shop standards and will report back with our results. For those interested in trying some out now, you can purchase Ultra-Sealant on the Nex-Gen site.

4 comments

  1. Robin on

    There have been quite few big claims from sealant manufacturers that have not been borne out in use. I think these sealant claims are one case where we all just need to say, “Oh really? Prove it.”

    Reply
  2. James @ Nex-Gensports on

    Nex-Gensports: We currently offer two types of tubeless sealant; Super sealant is for high pressure road tires and has been widely acclaimed. Ultra is formulated for lower, higher volume tires. Our sealants are based on a proprietary synthetic latex base which assists with longetivity and does not require Ammonia and acids to keep it from solidifying in the bottle/tire. Our claims of non-toxicity are fully explained on our website in a manner most people can understand explicitly. One of Bikerumors’ test riders is currently using our Super sealant product in our V7 aero gravel wheels.

    Reply
  3. J Jones on

    Fair to assume that any brand that does not specialize in the sealant chemistry is utilizing an existing formula (nothing at all wrong with that, ex: Bontrager, Specialized, etc), but the marketing claims that ring hollow are tiring and play right into that general dis-trust we’re all feeling. Especially hard to believe when every Nex-Gen product makes ultra bold claims backed by thin data. Would love to see proof in the pudding and not armchair chemistry about latex good/latex bad, since anyone with a rudimentary knowledge of chemistry knows it’s more complex.

    Reply

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