Hi everyone, bought 3 TPU Tubes from aliexpress and a patch kit from AliExpress. Installed them on my road bike. Took caution on not inflating the tubes so much outside the wheel, just enough to make installation a bit easier. No problems until I tested them and around 40 minutes into a ride I noticed my rear wheel was going flat. Thought maybe the valve was a bit loose so I inflated it a bit but just 5 minutes later it was almost flat again. Switched to a butyl tube and had no problem riding 1 hour more.
Got back home and it had a microscopic puncture, so I followed the instructions on how to patch it, and once it was patched it held air overnight just fine. Tried to install the third one on a wheel that I'm planning to use for a TT next week, it was a PITA because the rim beads are so tall and it's basically impossible to install any tire without levers. Once I got it installed I inflated it, lo and behold literally less than 20 min later it was dead flat again.
Is there any particular extra care that I'm missing? Or is it just because these are cheap TPU tubes? I bought them just because they were cheap, not particularly because I NEED to save extra grams, although it would certainly help and also marginally better rolling resistance.
by martynssimpson
10 Comments
you checked for debris? where is the puncture lining up with on your wheel? inside the rim side, or outside on the tire side?
I can only recommend TPU tubes with metal stems, like the ones from RideNow. Had plastic ones before, the went flat (or got ripped up) in a month. The ones with metal stems last much much longer, I only had to buy new ones after I crash into another biker. They deflate much less than the plastic stems (have to inflate once a week). 8-9 bucks for one is a good price I´d say
You are definetely doing sth wrong, but no one here can tell you, because nobody knows what you are doing wrong, as you do not give the cruical info.
But having all three being flat due to production issues is very unlikely.
Most probable problem is that you are very uncautious with your tire levers. And you shoul not inflate TPUs out of the tire as you did in the photo. TPU has a very low elastic behaviour, if you inflate them the deformation is permanent.
If you are not running 32mm tires you inflated them too much
Saving grams in the inner tube is not the place that I would personally look to “lighten the load”. That said, Thermoplastic Polyurethane is lighter and more durable than butyl. The only catches are that it costs more and it is less forgiving to install.
Assuming that you know how to install tubes (you said you replaced the TPU with butyl on the side of the road, so that seems like a safe assumption), we are left with one other glaring possibility. The TPU you bought on AliExpress for $7.61 are junk. My recommendation has always been to buy once and cry once with wheels, tires and certainly tubes. “Make a Wish” TPU tubes are going to ruin your ride. In cycling, you get what you pay for.
I’ve had better protection with TPU (Tubolito) than butyl. First check the tire for any debris, blow some air in the TPU tube with my mouth and mount to rim. Make sure the tubes are not stick on out the tire when you run the levers, I usually bounce the wheel up and down and make sure the tubes are centered to avoid this.
In my experience one has to be really careful when installing TPU tubes. I have stopped using tyre levers when installing TPU tubes, because I found that when the tube gets pinched between the lever and the tyre they can develop super tiny holes, like the ones you described. Since making the switch I haven’t had any more issues like this.
But not all tubes are created equal. I’ve had good results with RideNow TPUs.
I think the problem is “from AliExpress”. The cheap ones while light, are really thin and seem to be prone to the pinholes you describe. I had the same issue with the first ones I tried, 2 of the 3 got holes that were nearly impossible to find and patch, the third had the stem separate. If I ever go back to TPU, I’ll spend the extra for Tubolito or something similar.
Are the Orange tpu tube from the Think Rider brand ? Those are trash, failing at the valve bonding.
I is the ridenow metal valve tubes. Have put in 6 wheels and so far no issue or puncture.
I’ve used tubolito in my gravel bike too and had a puncture once when I pinched installing. This was 3 years ago when their valves were a bit crap so they would post you replacements for free when they failed.
I don’t use levers when installing so no pinch flats. I inflate a bit by mouth before putting them on the rim.
I wouldn’t bother with patching them tbh. I just replace at that price point considering how much other stuff costs on my bike and the frustration when I get a flat.
I personally think you had a pinch flat rather than a puncture. Very easy to do with TPU tubes if they get caught between the rim and tyre bead. While the metal valve stems are better, no reason that plastic one won’t get you plenty of mileage. You may lose more air over a few days but they are cheap!