These products are semi-solid rubber, with no air, so they can’t go flat. You can get either an air-free tire, which replaces the whole tube & tire (e.g. Greentyre), or an air-free tube, which fits inside your existing tire (e.g., No-Mor Flats. These are an as-yet unproven technology, and cycling equipment master Sheldon Brown and BikePro say they damage wheels.
BikePro on solid (tubeless) tires
A few years ago, a product was introduced that replaced the tire and the inner tube with a nearly solid polyurethane tire that didn’t use a tube. The polyurethane tire gave up some important ground adhesion characteristics as well as some real shock absorption provided by the tube. But its real failing was when many who bought them from us had their wheels fail altogether. It seems the polyurethane tire transmitted so much road shock into the rim that over time, the spoke nipples began to “back off” and become loosened, leading to catastrophic wheel failure with no apparent notice. We’re telling you this story, because all of a bicycle inner tube’s functionality isn’t obvious.
Carol Kent’s comments on No-Mor Flats (April 2002)
The actual fact of No-Mor Flats is that installing them takes no more time than fixing any flat, and they increase the weight of the bicycle by less than two pounds. When they are first installed, there will be slippery water between the tube and the tire, which may cause the tube to slip around, making riding rather hard. Once it has dried out (overnight, if you do it in the evening) riding is the same as before. There is more inertia, you will not coast as fast, but pedaling is no harder.
I consider mine a work bike. I run a housekeeping service and go from house to house all day with all the cleaning supplies. When I am not doing that, I am carrying groceries or going to Home Depot. I have absolutely no intention of arriving late or unloading everything on the road to fix a flat. I’ve used the bicycle for all my transportation for several years, approximately 3000 miles per year, with the only expense being replacing the chain twice a year. No-Mor Flats is great for me. I think they would also be great if a person were to travel for several months across country. The only problem with No-Mor Flats is that too few people are using bicycles for the purposes which make them ideal. (Apr. 2002)
Our review of GreenTyre (1998)
GreenTyre makes special flat-free tires. From the company’s home page: “Greentyres are molded from one piece of micro-cellular polyurethane. There’s no inner tube, only millions of tiny air pockets (or cells) that give Greentyres a comfortable and flat free ride.” They claim performance similar to standard tires. They’re wrong. The 24″ pair I got was so mushy it was like riding on flats. They do have some higher-performance tires for racing bikes, but the tires they have for most commuting bikes and mountain bikes don’t have very good performance. (They’re like riding slightly flat tires.) Still, if you don’t do much riding, or if you REALLY hate getting flats, or if you’re mountain-biking and don’t need the equivalent of a pumped-up tire, these might be for you.
GreenTyres also have environmental benefits. According to the company’s home page, “Greentyres™ are created out of a high-tech process but never at the expense of the environment. The process is clean, non-carcinogenic, is CFC free and releases no harmful toxins to damage the atmosphere. The product itself cures at ambient temperature so that there is no need to burn valuable and diminishing fossil fuels in post manufacturing vulcanizing, as required by rubber tires. The product lasts longer than rubber and when the tire eventually wears down it can be recycled.” Plus, of course, you save on materials by never having to buy another tire, tube, or patch kit.
To add to the excitement, GreenTyres are available in a variety of colors: black, gray, blue, red, green, and yellow.
GreenTyres are available in a variety of sizes, treads, and other styles. Each tire sells for $25, except most off-road styles which are $36. You can order online from the company’s website.
Besides the poor performance, the other bad news is that, unfortunately, GreenTyre’s customer service is so pathetic it’s incredible. In 1998 when I didn’t receive my order three weeks after I placed it, I emailed them and they told me they’d lost the order because they were moving their warehouse. They finally sent the package out, but sent it to my billing address instead of the shipping address (even though the shipping address was clearly listed on the invoice). It turned out that the tire I received wouldn’t fit my bike – an error I think that they’re partially responsible for because their website doesn’t provide any detailed help in selecting sizes. Then, amazingly, I traded about five or six emails with them in which they refused to answer my questions about tire sizes so I could try to get the correct size tire! They preferred to refund my money so they wouldn’t have to deal with me. I had to insist that I wanted a correct-fitting tire instead of my money back. They reluctantly agreed. I told them the tire I wanted, and this time they sent me the wrong color tire. I contacted them, and they said they’d take the wrong tire back and send me the right one. After another delay, I got an email from them apologizing, explaining that my tire didn’t go out because they were moving their warehouse that weekend! Uh, isn’t that what they told me a month and a half earlier when they lost my first order? That’s not all — their website ordering system has a few bugs. I couldn’t get it to work at all with Internet Explorer (latest version). And in Netscape, good luck if you accidentally order the wrong item and need to try to change your order…