But what’s inside those clinchers has been changing of late with TPU inner tubes flooding the market. Made of feather-light plastic (or thermoplastic polyurethane to be exact), TPU tubes are a fraction of the size and weight of regular butyl tubes and have a lower rolling resistance. These tubes are, however, spendier than the butyl standard and come with their own set of problems.
“In the past, TPU tubes have sometimes shredded themselves when riding on rough gravel. And many TPU tubes suffered from mysterious leaks,” Jan Heine of tire brand Rene Herse says.
“The valve stems of most TPU tubes are made from plastic, and they deform when the (metal) valve core is screwed in. Then the tube leaks, not because the material is porous, but because the valve doesn’t seal.”
Rene Herse has set out to solve this leaking problem with the release of its own TPU tubes, which feature patented all-metal valves. These valves won’t deform when the metal valve core is screwed in as their plastic predecessors did and claim to hold air for weeks at a time before needing a top up.
(Image credit: Rene Herse Cycles)
Made in Germany, the Rene Herse TPU tubes are made from a slightly thicker material than commonly seen on these ultralight tubes, which the brand says makes for easier installation and improves puncture and pinch flat prevention, even on uneven, rocky terrain.
The Rene Herse tubes weigh in at just 32 grams (for tires up to 32 mm), which is comparable to other TPU tubes with plastic valves, and come in 700c and 650b version with a variety of and widths ranging between 30-68mm, along with a choice of 50 or 70mm valves.
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“The new Rene Herse TPU tubes have been tested for thousands of miles on rough gravel roads and mountain bike trails before they were signed off for production,” the brand assures.
Available starting mid-April, the TPU tubes will retail for $30 directly from renehersecycles.com and selected retailers.
