2 Pack CYCLAMI Bike Tire Tube for 700C Road / MTB26/27.5/29 / Gravel, TPU Bike Inner Tube with 45/60/65/80/85mm Presta Valves, Ultra-Light TPU Inner Tube(Include Patch Repair Kits)

I am happy with these tubes. The light weight means less mass to accelerate to get up to speed. I run at 70-75 psi tire pressure on 28mm tires. It is necessary to pump up the tires even from day to day, so they don't hold air quite as good as butyl tubes. The metal valve caps are nice even though they are not functionally any different than the plastic ones.

Update 2: the second tube failed in exactly the same place about 60 miles after being installed. At least one other review had photos with exactly the same failure. Reducing rating to 1 star.Update: after riding these for about 100 miles (5 rides in 4 months) one of the tubes failed when crossing a railroad track. Tires were just pumped up 10 minutes before, not overinflated. I put in my spare and rode another 20 miles. When I checked the bike two days later, the replacement tube was flat. I pumped it and it seems to be holding for now but I'm pretty disappointed with the apparent lack of durabiltiy.I installed these tubes when replacing tires, just to try. Installation was simple - the bright green color makes it easy to verify that the tube isn't being pinched between tire and rim. Carried as a spare, the truly tiny size takes up much less space in my bike bag. The bright green aluminum valve caps are a bit over the top for this old guy, but I'm very pleased with the initial experience. Will update this review over time if my opinion changes.

Edit: valve core started leaking for like, no reason.Not too hard to install. Valves are a little long, more options there would be nice.This may be a new brand but I got a Vittoria latex tube at the same time as this and the valve core malfunctioned and was not replaceable 👎.Will update this review if they fail without good reason.Update; problem free for a few hundred miles now. Got a small hole, used included patch and it's held up. Kudos.

These TPU tubes cover the same territory as similar products from RideNow, Pirelli, Schwalbe, or Tubolito, but with a distinct plus: a metal valve stem, which makes them more compatible with the popular electric pocket inflators that are taking over the portable tool market (e.g. Fumpa, Cycplus). These tiny wonder pumps are great, but they produce a lot of heat. While it's easy enough to carry an extender hose to protect a plastic valve stem, said hose can get lost. A metal valve stem mitigates this risk. And the lime green color is fab - love it!

Update: 5.24.2024 - I had been using a butyl tube on the rear (since the problem discussed in the previous review), but recently ran over a nail. So I did a roadside installation of the TPU tube that has been my spare in the seat bag, since last September.The spare has been holding fine for a few days, so I ordered another "2-pack" ("2-Pack CYCLAMI 700C x 18-32C"). It arrived today, but it only contains one tube. Ripoff.------ previous review ------I installed these (F/R) in September 2023 in Shimano aluminum rims with Rubino Pro road tires. They have been great up until a ride yesterday, when I noticed that the rear tire was losing a lot of air. However, the tire wasn't completely flat. When I pulled the tire off, there were no visible punctures on either the inside of the tire or in the tube itself, but when I reinflated the tube (outside of the rim), it lost pressure within about 2 minutes.Later at home, I immersed the tube in the sink and discovered that it was leaking from two different locations, and in each location there were multiple leaks. But again, nothing visible to the naked eye.So I'm wondering if the plastic material itself is simply too thin and degrades within a few months to the point that it can no longer hold pressure.

Stem leak, reached out to Cyclami and they sent two replacements. Face it, this material looses air, while bike is not in use. Take it 80 psi on 30 to 50 mile ride and no loss of air. Flats have been legitimate. No more or less than regular tube. I started out with the overpriced more expensive brand and I prefer these. Never have patched one, so no comment.

I've used half a dozen of both Cyclami and RideNow tubes. (They are identical). They are light, low friction and compliant. But that comes at a cost. They are very thin and prone to fail at the stem. Tubolitos are slightly heavier but more reliable and safer. True, Tubolitos cost double the price, but when you are changing a flat on the side of the road -- or lying in a hospital bed -- you won't be patting yourself on the back for the money you saved. (These do make good spares, however.)

For a spare tube it takes up little room

Wanted to fit these tubes to my bike with deep rims - valve core isn't removable, so I couldn't fit an extension.I fit a tube to my shallow rim and it punctured on the first ride.