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Joe's No Flats Yellow Gel Innertube Sealant



Very good puncture preventative for the cost of a couple of tubes

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Joe's Yellow Gel Innertube Sealant is effective protection against punctures both in inner tubes and tubular tyres.

No cyclists like punctures, and anything that can help to avoid them has to be good, right? Joe's No-Flats are a company specialising in sealants with a range available to suit most applications. This Yellow Gel sealant is designed to be squirted inside the inner tube where it is claimed to be able to deal with any hole in the tread up to about 3mm in size.

First things first, installing the sealant. That's straightforward but you do need to have an inner tube with a removable core, so you might need to purchase a couple of new inner tubes first. Providing your tubes do have removable cores, you simply remove the core, attach the supplied hose over the open valve, attach the bottle on the other end, and squeeze away.

The 240ml bottle I tested is good for two wheels, with 120ml recommend per inner tube. I decided to be more thrifty and went with about 60ml in each inner tube. Valve core back in, inflate the tyre and give it a few rotations to spread the sealant inside the inner tube, and you're ready to ride.

As luck would have it when testing a product designed to protect against punctures, I got a puncture on the first ride out, thanks to the hedge trimmers. A small thorn had penetrated the front tyre and there was the telltale sign of yellow sealant bubbling out around the embedded thorn. I pulled over to the side of the road, extracted the thorn, leaving a hole about 1mm in size. The sealant bubbled out a bit more. I gave the wheel a few spins, and sure enough the bubbling stopped.

It was clear I had lost a tiny bit of pressure, but I carried on with the ride and another two hours later I returned home. I attached a pressure gauge, turns out I only lost about 8psi. If the inner tubes hadn't been filled with sealant I would no doubt have had to stop and change the inner tube, interrupting the rhythm of my ride, and most likely resulting in dirty hands.

As well as using it in inner tubes, I've also found the sealant ideal for fixing a recent puncture in a tubular tyre that had been freshly glued to the rim a few days before. Since adding the sealant, the tub is still holding pressure, so for anyone regularly riding with tubulars, this sealant is ideal. You can use it to fix a puncture, as I did in this case, but it might be more prudent to use it as a preventative measure, and squirt some in from the outset.

Joe's claim it lasts 12 months, I haven't been using it long enough to verify that claim. As well as the 240ml bottle, it's available in a 5 litre tub if you have a fleet of bikes you want to puncture-proof.


Very good puncture preventative for the cost of a couple of tubes

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Make and model: Joes Yellow Gel Innertube Sealant

Size tested: n/a

Tell us what the product is for, and who it's aimed at. What do the manufacturers say about it? How does that compare to your own feelings about it?

Fiber gel sealant for inner-tubes (not for tubeless system). Contains micro-fibers to prevent punctures in the tread up to 3 mm.

Non-toxic, Long lasting and easy to install. Easy to use spout fits into all valves.

For effective puncture resistance, add fresh sealant every 12 months.

If you get a puncture, always SPIN the wheel to distribute the sealant.

Recommended Amount for 1 26" or 29" inner-tube: 120 ml. 240 ml bottle is good for 2 bicycle wheels and 5 liter jerrycan is good for approximately 42 wheels.

Tell us some more about the technical aspects of the product?

Micro-fibre gel flows around tube to seal punctures as they happen

Fibres can seal punctures up to 3mm in length

Non-toxic, long lasting and easy to install with easy to use spout.

Includes core remover key for use with schrader / car type valves

Can also be used on presta valve tubes fitted with removable cores ( superlight tubes and Schwalbe branded tubes only)

240ml bottle will effectively treat two MTB tubes or 3-4 road tubes

Rate the product for quality of construction:
Rate the product for performance:
Rate the product for durability:

Too soon to tell if it really lasts 12 months like the company suggests.

Rate the product for weight, if applicable:

Adds a tiny bit of weight to each tyre, not that you'll really notice.

Rate the product for value:

Tell us how the product performed overall when used for its designed purpose

Does what it says on the tin. This is a really useful product for daily commuters, tourers and Audax riders, but racers and performance minded road cyclists can also benefit.

Tell us what you particularly liked about the product

Easy to install.

Tell us what you particularly disliked about the product

Adds a tiny bit of weight to the bike.

Did you enjoy using the product? Yes.

Would you consider buying the product? Yes.

Would you recommend the product to a friend? Yes.

Overall rating: 8/10

About the tester

Age: 31  Height: 180  Weight: 67

I usually ride:   My best bike is:

I've been riding for: 10-20 years  I ride: Every day  I would class myself as: Expert

I regularly do the following types of riding: road racing, time trialling, cyclo cross, commuting, touring, mtb,


David worked on the tech team from 2012-2020. Previously he was editor of and before that staff writer at RCUK. He's a seasoned cyclist of all disciplines, from road to mountain biking, touring to cyclo-cross, he only wishes he had time to ride them all. He's mildly competitive, though he'll never admit it, and is a frequent road racer but is too lazy to do really well. He currently resides in the Cotswolds, and you can now find him over on his own YouTube channel David Arthur - Just Ride Bikes

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