URSA 29plus Frame


URSA 29plus Frame


Backcountry bikepacking, plus bike racing, trail riding, rocks, sand, & snow: The URSA 29plus has you covered. Loaded up to survive or built out for the trail, this bike puts a smile on your face. The URSA 29plus frame offers incredible versatility and industry leading drivetrain and tire clearance! 

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  • Oversized 44mm Headtube for tapered or straight steerer tubes
  • Headset ZS44 Upper / EC44 Lower
  • Compatible w/ 100mm suspension forks and rigid forks w/ 483mm to 490mm axle to crown
  • Fits 29plus tires up to 3.25" wid
  • English threaded 73mm Bottom Bracket
  • Boost 148x12mm Thru Axle Rear
  • 31.6 Seatpost Size and 34.9 seatpost clamp
  • Dropout inserts with a derailleur hanger or single speed, also available w/ Rohloff inserts
  • Rear PM disc brake mount


  • Made in USA
  • CHUMBA USA Select Steel:  Custom Oversized double butted 4130 Chromoly tubes (uses a blend of heat treated and non)
  • CHUMBA Custom half yoke chainstay and bridges
  • ISCG-05 built into the custom chainstay yoke for use with a skid plate
  • Exceptional chainline and tire clearance
  • Ample mud clearance
  • Room for three bottle on all sizes
  • Room for 4 bottles on Large and XL frames
  • Mounts for Anything Cage on Downtube
  • Rear Rack Mounts

We also have a limited few URSA 29plus frames left in the 157x12 spacing in Desert Sand and Storm Gray, contact us for details. Sizes in this config are3 XL frames, 1 medium, 2 small