The Bumper

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  • Regular price $15.00
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Have you ever wished you could bump up the resistance on almost any gripper? 

Cannon PowerWorks developed The Bumper with recommendations from a spring manufacturer. Used properly, it will safely add 1 to 7 pounds of resistance to almost any gripper. The added resistance comes from soft, natural rubber, which will not damage the gripper spring. Our extensive testing has proven the durable rubber will last for thousands of reps. This innovative and exclusive new product is a must-have for anyone training to close heavier grippers. 

The Bumper
will fit all IronMind Captains of Crush, Standard, GHP, Grip Genie and Heavy Grips grippers. Some other grippers have too small or too large of a coil diameter to insert The Bumper. If you have a question about compatibility, email  


How it works: 

  • Center the rubber within the spring coil. Then, to get the initial fit set correctly, tighten the knob in half turns until The Bumper is held in the coil.
  • You should be able to pull The Bumper out of the coil with a heavy drag on the inside of the spring coil, but it should not be so tight it is stuck. If it is too tight, loosen the knob slightly until the drag is correct. After testing the drag for the initial fit, always re-center the rubber portion within the spring coil.
  • From the proper initial fit, every FULL revolution of the knob will add approximately 1.5 pounds of resistance. Turn the knob in half turns, aligning each time with the gripper logos to help keep track. Two half turns (180 degrees each) count as one FULL revolution. The adjustability is infinite and slight adjustments will yield slight changes in resistance. If you lose exact count of the revolutions, then start over at the initial fit.
  • Add a maximum of eight half turns (four full revolutions) from the initial fit. Exceeding this recommendation may compromise the natural rubber component. See warnings.
  • Always loosen and remove The Bumper from the spring coil after use. Wipe off any lubricant that may have transferred from the spring.

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