IAS Instant Active Suspension

A totally new suspension design from Tomac Bikes, Instant Active Suspension is a simple yet effective system that improves overall suspension action without sacrificing pedalling efficiency or rear end stiffness. With IAS, a CNC machined link between the rocker pivot and seat stay end, carried by high end full compliment bearings, allows the rear shock to initiate more quickly and the suspension to be more responsive. Laboratory tests have shown a 30% reduction in reaction to inertia. What does this mean in layman terms? IAS suspension makes quick work out of bumps, especially repetitive hits (think braking bumps) where quick suspension action means less transmitted to the rider. Because the suspension also initiates quicker, test riders consistently noted that IAS equipped bikes easily drives through bumps, maintaining speed rather than letting the rough terrain slow the bike down.



Quotes from test riders:

"I really like to climb rough terrain, and the first thing I noticed about the new suspension system is that you can more easily stay seated on the bike and pedal through the rocks. Your forward momentum isn’t disrupted by the terrain and you can build speed rather than be slowed by the rough."

"The big improvement for me was through braking bumps. The rear wheel just stayed glued to the ground, even when I was pulling hard on the brakes."

"The suspension action was what I expected: super smooth and very consistent for me. But I was most surprised at how stiff the rear end is. I was riding down a trail that was covered in rocks and I could change direction at will. The bike with the new suspension system is extremely confidence-inspiring for me."

IAS Benefits

  • Improved suspension initiation without elimination of efficiency
  • Immediate activity to absorb bump forces
  • Improved suspension action at bottoming
  • Neutral pedaling without pedal kick back in rocks or roots
  • Increased options for axle path and shock rate
  • No need for Pro Pedal or other platform style damping system
  • Excellent shock initiation and no need to run excessive sag to get plush suspension
  • Consistent suspension action throughout suspension stroke
  • More consistent suspension action from bike to bike
  • Stiff design with fully triangulated swingarm and short links
  • Straight seat tube means any front derailleur will work (SRAM, Shimano, FSA)
  • Straight seat tube allows for increased post insertion
  • Dual triangle design for high level of stiffnessIAS
  • Short links to actuate shock with small number of bearing in frame