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| A WTB Nano Air tube in 29"er size next to its butyl equivalent. |
This review is going to focus on the Nano Air TPU tubes from WTB exclusively as the product is going to see a lot more use than a tubeless repair kit for most cyclists. That said, I will be posting a separate look at the Rocket Repair Kit later on. The introduction to the tubes can be seen HERE.
Those not familiar with TPU tubes should know that they have had a slightly marred introduction to cyclists as the first brand to widely distribute these types of tubes suffered a rash of failures which colored a lot of people's opinions about these products for use as inner tubes. That said, subsequent improvements have come along and I think that these deserve a second look if you happen to be one of those who has a negative opinion on TPU for inner tubes.
What The Heck Is It? TPU stands for "Thermoplastic Polyurethane", a flexible plastic with an inherently low weight. This material is fashioned into a "hose" shape and the bonded at the ends together to form a hoop which can then be fitted with a valve and used as an inner tube in a bicycle tire. It is very durable, can last for years, and is 100% recyclable. The TPU also resists rolling resistance issues and has very similar characteristics to a latex tube, only TPU holds air pressure far better. In fact, I have experienced better air retention with TPU tubes than with many butyl rubber tubes.
Downsides are that it doesn't stretch all that much, so you must fit the tube a bit more precisely than you can get away with using a butyl rubber tube, which can stretch seemingly infinitely. The cost of TPU tubes can be as much as 3 times that of a butyl rubber tube as well. Although budget TPU tubes can be had from Amazon, I cannot vouch for their quality.
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| The weight savings is no joke. This alone may be the best reason to go TPU. |
WTB Nano Air: TPU can be made to be about any color and can even be "clear", but why on the Earth did WTB choose this tan color? Blecch! Good thing I don't have to look at this once it is installed! I received three TPU Nano Air tubes. One each for 29"er, gravel, and road. Currently I have more bikes set up with traditional tubes that are 29"ers so I decided to A-B the 29"er Nano Air tube against the traditional butyl rubber tube. I chose my Karate Monkey as the test bike.
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| I installed the Nano Air tube in this Maxxis Ardent tire with a rim brake set up. |
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| You can see how the tube is joined here in this image. |
The tube already had a thin film of talc on it out of the box, but I would definitely recommend talcing the inside of your tire if you can. This will make for a tube that doesn't get snagged or stuck on the casing and should provide a longer lifespan of the tube. Any tube, really.
In the case of the Karate Monkey, I was a bit disappointed when I initially set up the bike with the Maxxis Ardent tires because they felt dead and "draggy", as if they had a higher rolling resistance. Once I installed the Nano Air tube in the rear tire I realized that it was not the tires so much as it was that tube. The lighter weight TPU and the way it can move against the casing made for a much livelier and enjoyable ride feel.
Incredible air retention allowed me to ride for an entire month without checking the air pressure and when I did it was only down a few pounds. That could be attributed to the opening of the Presta valve and putting the pump head on the valve stem. At any rate, these Nano Air tubes hold air like a champ. I used the gravel sized one in a static air pressure retention test in the shop and found similar results. The road sized Nano Air went to N.Y. Roll, as he has road bikes. He decided to keep it in his repair kit as a lightweight repair option.
With all the glass around here this Spring I never encountered a flat with the Nano Air tube, but had I gotten one there are two glueless patches which come with each Nano Air tube with which I could make a repair with.
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| The Karate Monkey which I installed the WTB Nano Air tube in the rear tire. |
Conclusions: I see no reason not to use a TPU tube like the Nano Air for daily use, and with similar performance gains to latex, this beats those types of tubes hands down simply on air retention alone. Tubeless has a legitimate competitor now in the TPU tubes and I would suggest that if you have a bike that doesn't get a lot of attention, these TPU Nano Air tubes could give you near-tubeless benefits and no messy sealant to re-up or clogged valve stems to deal with.
Obviously, a Nano Air tube would also be a prime candidate as a bail-out option for a tubeless set up due to the small pack size and super light weight. However; I think these TPU tubes, and in particular, the Nano Air tubes, are a perfect fit for many cyclists that don't want to deal with tubeless tires, yet want to upgrade from traditional butyl tubes. The TPU tubes like these Nano Air tubes are pricey, but if they last for years, unlike sealant does, they would have to be considered "better" at that point. Of course, "better" is a term best defined by the end user, but I do feel that the TPU tube has a place now in the cyclist's kit.
