Sinister Frames

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The Sinister Mustang is 100% carbon fiber free. It’s built from 6061 T6 right here in the US of A by the craftspeople at Sinister bikes. It’s under 3-1/2 lbs, built tough for years of race or race training. Removable fixed or adjustable single-speed dropouts (call for availability). Our exclusive right-side only semi-yoke to prevent chain drops from sawing the frame in half.

Our roots are in aluminum and so should be your future.

No more slipping seat posts or jammed phone calls. It’s safe to remove the tin foil liner from your helmet.  We got your back...


  • Racing and performance geometry
  • All 6061 aircraft construction
  • All design, machining, welding and finishing done in New England (USA)
  • Plenty of mud clearance
  • Engineered for quality ride and trail feel
  • 1-1/8" cup type headset ready
  • 27.2 mm seat post
  • 31.8 mm seat post clamp
  • Four frame sizes
  • Designed by FTW and the staff at Sinister bikes
X-Small Small Medium Large
Head Angle 70 deg 70 deg 70 deg 70 deg
Seat Tube Angle 72 deg 72 deg 72 deg 72 deg
Seat tube length (center to end) 16" 17.5" 19"
Eff TT Length 20..9" 22.2" 23.5" 24.3"
BB Height 12.0" BB shell 12.0" BB shell 12.0" BB shell 12.0" BB shell
CS length 16.7" 16.7" 16.7" 16.7"
Head Tube Length 4.5" 4.5" 5" 6"