Schwalbe SV21 Bicycle Inner Tubes 27.5 inch x 1.50-2.4 650B (2 Pack)

These are a great tube. Heavy duty yet still feel comparable in weight to a lesser thickness tube. They hold air pressure longer and I have also noticed next to no flats from small punctures. These will be almost bullet proof with some sealant added to them. I will definitely continue to buy these as needed in the future.

We had these same tubes on our bike for over 1.5 years and they held up. My husband occasionally commutes to work on the bike and they have been great. 👍

These tubes are a one size fits many size tires. About seven different sizes I believe. This works well when using this tube along with tire inserts such as Tannus Armour. Simply choose the Schwalbe tube with its largest size being your actual Tire size and the tube fits very well with tire inserts in place. This worked perfectly for me with my 27 1/2" x 2.4" inch gravel tires and Tannus Amour inserts. I love the "feel" of the ride.

Good quality and price. Delivery was on point as well.

Put in this tube to replace a damaged OEM tube. Pumped it up, held air, and overnight I double checked, and it lost half the pressure. It was leaking at the removable valve core where it inserts into the stem. Tightened to finger tight, and still leaking. Tightened it with needle nose pliers, and it stopped leaking. Except it was leaking from the valve top nut VERY slowly, but enough I didn't want to leave it. I had to tighten the top nut with needle nose pliers, and it stopped that small leak too.It works for now, but I likely won't be able to pump air into it in the field since I tightened the top nut with pliers. I'll update review once I have to use the second tube.

Installed these 650b tubes on a new Velo Orange wheel. They've perform well. No air leaks!

Not good because of thickness in area around valves rubber isn’t flexible so tire is pushed away from rim causing uneven seating and bumpy ride. You can see difference in pictures

These innertubes are very tough and durable. A very little amount or no air is required to keep the tire hard. However, installation is very slow going to keep the tube installed ununiformly in the tire without breaking the tire seal to the rim.