As it has become my custom these days, I contacted Tannus UK as soon as I was made aware of the existence of this new breed of non pneumatic tyres, in order to get a sample to test. Initially I thought they were just a refined version of the old and horrible solid rubber tyres that are still fitted onto kids’ bikes to make their life miserable, offered with a broad colour palette, but they are not. Tannus tyres are in fact a product of the latest R&D into nanomaterials. A nanofoam with the same density of an inflated pneumatic produces a 700c 28 mm tyre that weighs only 430 grams and not only in Korea, but even on my kitchen scale! Incidentally that is exactly the same weight of a Conti Gatorskin 28 combined with an inner tube.
Let’s start by saying that not having the mediatic power of a national newspaper, I got a pair of these in white rather than the black I would have preferred. The net result is that I fitted them onto my wife’s bike, forcing her to use the newly acquired leather working skills to craft a pretty matching saddle out of a Fikiz Arione shell, check it out!
The other reason I fitted them onto her bike rather than mine is that I learnt that this particular model (a pair of Musai with the softer S1 compound) and size requires an internal rim width of 13 to 16 mm and I only own wider tubeless ready rims these days. So onto the Mavic Open Sport they went.
When I visited the Tannus pop up shop in Aldgate East, I had a good chat with the guys there and I learnt three important facts:
- Matching the tyre with the rim width is crucial and they have a range of models to cater for that to an extent
- The tyres are fitted by means of 40 plastic pins that will not come off without the risk (almost a given) of damaging the tyre itself.
- Skidding on a fixie with these has a slightly different bounce to a pneumatic tyre, but I was way over my head on this topic, so I just noted and nodded. I then regained points by showing them how to convert a Campagnolo 9 speed lever to run a Shimano cassette. Pride restored!
The second point also explained why the shop assistant was so keen to fit the tyres himself. Once they are on, they won’t come off without a fight, so if you make a mistake in the fit, that could be costly. But of course being the “know it all” bod I am, I was having none of that and walked away with a pair still in their packaging. Result!
When you buy a Tannus tyre you also get a tool that could be recycled for a Wolverine themed fancy dress party and three sets of pins of different sizes to match different rim widths. You also get an instruction booklet written in Koreanglish, but with plenty of clear images to guide you through what you should do and more importantly what you should avoid doing.
The fitting is labour intensive rather than difficult and even a diligent chimp can master it if it doesn’t end up swallowing all the pins in the process. You need to choose a pin size which is around 3-4 mm wider than your ETRTO size: for example the Open Sport has an inner width of 14.5 mm on my Vernier, so I chose the red 17.5 mm pins. The 40 pins need to be inserted at the base of the tyre the correct way round, then the tyre mounted on the rim and every single pin needs to click into the rim bed by means of the Jack the Ripper type tool. It took me 30 minutes to fit the first tyre and 15 to fit the second. If you get the hang of it, you might be able to do it in less than that. If you don’t, despair not: the next time you will need to fit them you’ll have probably forgotten everything about it anyway.
Pins need to be inserted one by one at the base of the tyre…
… and then secured inside the rim bed by using the supplied tool
Once the tyre is on, you need a hand grenade at close distance to remove it, or more practically you cut the tyre and rip it off (I was told). What I mean is that the tyre is securely hooked onto the rim, which is nice given the current trend of high pressure clinchers blown off the rim by extensive braking.
I then caught a cold and four days later, on a beautiful if frosty morning, I finally managed to give them a spin on my commute to work, which includes 13 miles each way of all London surfaces: good and bad tarmac, cobbles, hard pack gravel, broken lava type surface with tree roots sticking out and a few puddles of frost hardened mud (softened in the afternoon). I was determined to take a bit of shine off the white.
Much to my surprise, the Tannus feel actually quite nippy and are keen to pick up pace and roll smoothly. Flipping the coin, they feel quite harsh on the cobbles and I have therefore ruled them out already for the 2016 Paris-Roubaix Cyclo.
If you bounce a wheel with tyre on a hard floor, you get a sense of how it will ride. The higher the rebound, the more elastic the tyre is, or in engineering words the smaller the elastic hysteresis is. The tyre will be faster, as no energy is lost and converted into heat. A Tannus tyre bounces back surprisingly well for a non pneumatic and onn the smooth tarmac stretch of the commute through Syon Park I didn’t feel short of speed or acceleration. However, it doesn’t bounce back as high as a good pneumatic tyre, which accounts for the dead feel over bumps and cobbles.
The grip seems adequate, but a more demanding ride with descents and switchbacks would be needed to test them properly. When riding over broken surface, the tyre doesn’t adapt to the changing terrain as well as a low to medium pressure pneumatic. The degree to which the tyre is allowed to elastically deform is limited and in that respect it behaves like a 100+ PSI inflated tyre.
On balance, I did like them a lot on smooth tarmac and on hard packed gravel and less so over more demanding surfaces.
After a few commutes, I feel like drawing some conclusions: the Tannus are a leap in the future compared to a classic solid rubber tyre and their road performance is not far off that of a decent road tyre and probably in line with a budget wired version. However, bumpy roads and cobbles highlight the inferior elasticity of the foam. They come at a weight which is competitive with a road tyre + inner tube and if you think you won’t have to carry spares, tyre levers and a pump (not to forget the all important 10 grams of compressed air in a pneumatic), the system is actually significantly lighter! Not having to carry a whole lot of paraphernalia brings other advantages: no need for that hideous Topeak saddle bag and no need for that expensive jersey with massive rear pockets.
The main benefit and selling point, as stressed by the manufacturer is they are of course puncture free and on top of that they offer high mileage. Tannus claim 6,000 miles on these and if they are not abused, it sounds realistic. For urban use, folding and utility bikes and all those bikes with hub gears where the rear wheel is a nightmare to remove these are head and shoulders above a pneumatic tyre in terms of practicality, unless you live in Wallers and your commute involves a daily crossing de la Trouée d’Arenberg of course.
As a training tyre for your road bike they can be just about good enough in terms of performance to keep up in the Sunday club run, but you need a dedicated wheelset for these, if you want to use pneumatic tyres for race day or long summer sportives on your best ones (which you do!).
I would advise against using a pair of Tannus as touring tyres for your next fully loaded Land’s End to John O’Groats: the harsh feel over less than perfect surfaces can add up to a lot of stress on your joints if you plan to ride for many hours every day. Of course on your tourer you can be creative and run a combo: a pneumatic tyre at the front for comfort and a Tannus tyre at the rear, where comfort is less important, punctures are more frequent and more labour intensive to fix… just don’t get a white one in that scenario, as you might not be able to find a pneumatic that matches it.