Can I use this tube in a 700x40c gravel tyre?

No — the rated maximum is 38c. Using a tube outside its rated width risks the tube bunching inside the tyre and causing an unpredictable blowout. For 40c and wider, use the RideNow 700x32-47c 45g variant.

Is there any performance benefit over a standard butyl tube in this width range?

Yes — lower rolling resistance from TPU polymer is measurable (approximately 0.5-1 watt per wheel vs quality butyl at race pressures) and the 90-100g weight saving per wheel reduces rotating inertia on long climbs and accelerations.

RideNow

RideNow 700x28-38C Light TPU Inner Tube (39g)

Name: RideNow 700x28-38C Light TPU Inner Tube (39g)
Brand: RideNow
SKU: CMB_WOW_RNTPU-SV2838_65mm
Price: 1150.00 INR
Availability: InStock
Author: InstaSport Editorial

₹1150.00

Description

Features: Materials - 180000 molecular weight high-performance TPU particles from Germany Rigorous research and development design High quality air valve Unimaginable lightness TPU+metal composite valve Detachable presta valve cores Specifications: Size: 700x28-38c Weight: 39g Country of Origin: Chi