Today, WTB announced their all-new Proterra lineup of wheels. While these new wheels consist of four different widths and builds, I’m going to focus on the gravel plus version, the WTB Proterra Light i25. Why? Because rolling 650b is just so much fun on gravel bikes and the i25’s represent an affordable way to add a 650b wheelset to your gravel repertoire.

WTB Proterra Light i25 650b Features:

  • Lightweight 6069 alloy
  • 650b diameter
  • New TCS 2.0 construction
  • 25mm inner width
  • TCS Solid Strip further protects the spoke holes
  • On-Ramp Bead keeps the bead in place for proper seating
  • Sapim aluminum nipples for light rotational weight
  • Double-butted j-bend spokes
  • Sealed cartridge bearings
  • Shimano HG or SRAM XDR only
  • Centerlock rotors
  • Hand built in California
  • 6-pawl freehub with 3.7-degrees engagement
  • Weight: 1717 grams (wheelset)
  • MSRP: $649.90 (wheelset)
WTB Proterra Light i25 650b Rear Wheel

WTB Proterra Light i25 650b.

Easy Gravel Plus

As proponents of 650b tires for gravel riding and racing, these wheels look to be a great option as a second set or as a durable wheelset for rowdy terrain. Bikepacking or mixed terrain riding is so fun on gravel plus and the Proterra Light i25 wheelset will get you there.

Something else that stands out is the whole TCS 2.0 system. WTB’s new Solid Strip liner looks to eliminate tubeless tape sagging and failure at the spoke holes. Adding that will also make tubeless tape installation easier. In addition, the On-Ramp lip will certainly provide a better tubeless seating and tire removal experience by keeping the bead in the sweet spot and, conversely, keeping it out of the sweet spot when it comes time for removal. I’m anxious to give it a try. 

WTB Proterra Lightweight i25 Rim Profile

The i25 rim profile shows the On-Ramp lip and other key dimensions.

WTB Proterra Light Gravel Wheelsets

No hero shots of the i25 are available, but here’s the i23.

The full Proterra lineup does also include the i23, which is a durable 700c gravel wheelset and delves into XC and Enduro land with the Proterra Light i27 and Proterra Tough I30, respectively. These wheels will initially only be available direct from WTB, but will trickle into shops as supply increases. 

WTB Proterra Wheelsets

The full Proterra gravel, XC and enduro lineup, with all its specs.

Learn More/Buy: Visit


About Author

A native of the Pacific Northwest, Jason quickly developed a love for the outdoors and a thing for mountains. That infatuation continues as he founded this site in 1999 -- sharing his love of road biking, mountain biking, trail running and skiing. That passion is channeled into every article or gear review he writes. Utah's Wasatch Mountains are his playground.

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