Maybe your new year’s resolution is to lose a little weight. Riding can be a great way to get yourself out the door and on the way to fitness, but you actually have to get the bike down from that hook in the garage and do it. I’m assuming that for most of us reading the site on a regular basis, the threat of a puncture and the need to inflate your tires on a regular basis isn’t a deterrent to getting out for a ride. But for a large chunk of the population who ride far less often, flats and under inflated tires are a big deal. In fact, Specialized cites a study from German Sport University Cologne that claims up to 90 percent of cyclists ride with under inflated tires, and 55 percent of riders have at least one puncture per year. That may not sound that bad, but when you lack the ability or desire to fix a puncture yourself and you end up having to bring it to a shop (or having the shop come to you), all of a sudden your quick ride becomes an ordeal.
Rather than dwelling on the rider’s ability to fix a flat, with the help of Tannus, Specialized is taking a completely different approach – airless tires. This certainly isn’t the first use of airless tires in the bicycle world (technically, the very first tires were airless as solid rubber). But just like all the other components of the bicycle, the technology has drastically improved with the times. Tannus announced their newest airless tire back in 2015 with their Aither 1.1 which promised better ride characteristics while maintaining the completely flat free feature.
Now, that same technology is available on the Specialized Alibi for a truly maintenance free tire that never goes flat and never needs air…
Emanating from South Korea, the Aither 1.1 tire is completely made of a special EVA foam they call Alpha Olefin Block Co-polymer. Similar to the EVA foam used in athletic shoes, the millions of microscopic air pockets in the foam provide the tire some ‘give’ for a ride that mimics that of a tube tire, but remains completely puncture proof. There is no rubber or coating of any sort on the tire – just foam that goes into a mold. Because of that, Specialized says you shouldn’t try any rad skids and like we’ve seen on other airless tires, grip in the wet might be compromised. Equipped as a 700 x 38c tire, Specialized claims the tire and clip system has the same weight as a Nimbus Armadillo 38mm tire and tube at 900g. It also has the added benefit of being 100% recyclable.
Manufactured with the same tread pattern you’d find on a Specialized Nimbus tire, Specialized rates the tires to 3,000 km (1,864 mi).
While the Aither 1.1 tires can be mounted to many standard 21mm internal rims, in this case Specialized chose a specific rim that is 21mm wide (internally) and a bit deeper that would provide the best handling and stability for the tires. Each tire is mounted to the rim with a number of plastic tongues that thread into the tire and then snap into the rim with a special tool in about 15-20 minutes. Once the tire is worn out, you will have to take it to your local Specialized dealer to be replaced – either with another Aither tire or a standard tubed tire. The rims fitted to the Alibi will still accept a standard tube and tube type tire, even though the valve holes have been covered over with stickers.
Elsewhere on the bike, the Alibi Sport is exactly what you would expect from a $550 fitness hybrid, and more. At this price, you’re not going to be getting super high end components, but the Shimano Altus 3×8 drivetrain includes an 11-34 cassette, a Shimano triple, and EF500 EZ Fire Plus shifters with integrated brake levers. Bonus points come from the use of a standard stem (no adjustable quills) and a funky handlebar with a cross brace and Body Geometry Ergo grips. Along with the Milano saddle and large Specialized City Platform pedals, the touch points are all extremely comfortable.
The frame also has some features typically found on higher end bikes with internal cable routing and hidden fender mounts (shown installed above). There are also plenty of braze ons for racks front and rear. Called Rainbow Tint/Black Reflective, the paint on this bike is a brownish-grey with deep metal flake that sparkles in the sun and black reflective decals – which is a nice touch.
For a large hybrid, 27.69 lbs with pedals, a bell, and a kickstand (not included) seems like a very reasonable number.
This isn’t exactly the kind of bike I’d normally be excited about reviewing, but in this case I was very curious about the airless tires. I couldn’t wait to get the thing out on the streets, so as soon as the box arrived I was in the shop putting it together. I have to say that as a (former) obsessive compulsive shop mechanic, the build on the Alibi Sport was impressive in terms of things being greased and properly assembled. The only real issue came from a rattling in the front wheel. After pulling off the sticker that covered the empty valve hole, I was able to shake out an aluminum disc that was left inside the rim from the valve hole being punched. These kinds of things happen all the time so it wasn’t a big deal, just something that you may want to check.
Once assembled, it was straight out for a test ride where the tires felt… mostly normal. Honestly, on smooth pavement, most consumers would probably not even realize they were on different tires. There is a bit of compliance to the Aither tires that makes them comfortable to ride, though they do ride like a 38mm tire inflated to 55-65 psi. The only time you may notice that something is different is on big impacts – riding over sewer grates, curbs, etc. In these instances, the tires do have a noticeable thud that is a bit more aggressive than a tube type tire, but you have to consider that big impacts on a tube tire could result in pinch flats rather than just discomfort. I have yet to ride the bike in the rain, but traction on dry and damp pavement was certainly adequate.
Ironically, after riding around town and down to one of my favorite photo spots in an alley behind buildings which is notorious for flats, I got back to my shop and found a small piece of metal sticking out of the tire. Surely, this would have caused a flat on a normal tire, which is one of the strangest parts of this bike – I’m so pre-programmed to carry a tube and a flat kit, that I feel almost naked taking it out for a spin. Never again do you have to worry if your tires are inflated to start the ride, or worry that you’re going to get far from home and get a flat (or multiples) and run out of tubes/patches/boots/etc. You may not even think about it, but the ability to leave the pump and flat kit behind provides a sense of freedom that many casual cyclists will love.
Now, is this going to replace my bikes with tubes/tubeless/tubulars? Of course not. While the Aither tires seem to offer plenty of performance for those interested in a bike like the Alibi Sport, there are still performance advantages to be gained from more traditional tires. That isn’t to discount the Nimbus Airless tires and the Alibi Sport however. I liked the bike so much that I bought it and gave it to my dad for Christmas. Realistically, he’s the perfect use case for the Aither tires. Riding mostly in good weather with my mom on camping trips or occasional jaunts around the neighborhood, in his case the peace of mind provided by never having to use a pump again seems to outweigh the performance benefits of a standard tire. Or at least, that’s my theory anyways. In reality, this will be a great opportunity to see what he thinks of the tires after a season of use and how they’re holding up.
Specialized Nimbus Airless tires are available on the Alibi, Alibi Sport, and Alibi Sport EQ in both standard and step-through frames from $490-$600.