ZOL Mountain Bike Bicycle Inner Tube 26" x1.95/2.125 Presta Valve 48mm

I got this tube simply because it looked like the best deal for a standard Mountain Bike tube on Amazon. I needed the presta stem, not schrader, so I went with this tube.I have had no problems at all with this tube. NOTE HOWEVER that the stem did not come with a lock screw to tighten the stem against the rim. I'm not complaining, as I had about 100 in my garage and just used one. But it's something to note in case you're interested.Simple tube that does the job.

I bought two tubes. They look fine, however the stems are cheap and of very poor quality. After installing, went for a ride only to discover rear tire totally deflated the next morning. I traced the issue to the valve insert. Even after it is screwed closed it leaks. It's not so much the cost that bothers me, but the fact that it requires effort to change a tube plus do we really need more rubber and plastic in the landfill?I thought about returning, but since I bought as a pair and the front is not (yet) leaking there is no way to return just the defective tube. So looks like I'm stuck with it.Very disappointed. Will avoid purchasing or using Zol products on my bikes.

I bought these to have as spares in the seat bag on my bike. I didn't have a flat until after a month of purchase. The tube was removed from the box and placed in the seat bag - never unwrapped, never subject to anything. I got a flat out on the trail and went to use this tube, unrolled it and started putting a little air in give it shape and it had a hole from the factory rendering it useless. And now Amazon is saying the window to return is closed - not cool. I suggest anyone that buys these put some air in the upon arrival to make sure it not defective.*update* Amazon altered their return policy so I can send the defective tube back - thank you Amazon. But the rest of the review still stands. Check them when you get them so your don't end up with a useless tube when you need it.

Initial quality is real good but these tires won't last a year. After a year, the tube will develop micro-tears. I couldn't inflate these tubes past 55psi before another hole will open up. Mind you, I had these tires on a 2.1" tire--the upper limit. I would say it would be safer at the lower limit of a 1.9" tire. Come to think of it, these tubes have a small range, 1.9-2.1. Maybe elasticity is not its strong point.

My e-bike would bend and eventually break stems, both presta and schrader. The thicker the inner tube the worse that effect would be. This tube is very thin, so I use an insert to protect against thorns, screws and nails, but the benefit to an e-bike is the flexibility of the stem. Even if the torque from the motor twists or deforms the stem, it doesn't break as often. Also, this tube won't take more than 40-50 lbs before it starts to really get flats. 30lbs is really low, but I found works well with this type of cheap tube. A little extra rolling resistance, but longer between flats.

3 of the tubes seem great (have yet to test drive them) but 1 of the 4 had a defective thread on the stem. Unfortunately I didn't notice until after I reseated the tire on the rim. Had to start over to remove it and use a different tube.See photo at base of thread.DOUBLE CHECK BEFORE YOU INSTALL AND SAVE YOURSELF SOME TIME AND EFFORT.

I don’t know if these are just a crappy made product or if my husband is extremely rough on his tires. But the first time out on his bike after replacing with these the tire blew again.

So the product sprung a leak from what appeared to be a manufacturung weakness and needs to be replaced. I ride my bike for short trips on city roads mostly. For comparison - the tube that came with the bike lasted 14 years. The front tube is original. This one last for fewer than 20 rides. Company would not replace.