Thunder Shift
Superior Performance Through Superior Clutching

TRA Thunder Shift Rollers

The all new Thunder Shift Rollers (TSR) are another great tuning component for the Ski-Doo TRA clutch.  The TSR can be used with stock TRA arms or the adjustable Thunder Shift Arms.  Thunder Shift Rollers are available in 1mm oversize (12.5 grams each) or 2mm oversize (15.5 grams each).  A standard Ski-Doo roller weight is 10.0 grams.  Thunder Shift Rollers are heat treated and bushed.  Thunder Shift Rollers are a bolt on high performance item from Thunder Products, Inc.

Here are some reasons you may want to use:

 Thunder Shift TRA 1mm or 2mm oversize Rollers:

1. You may want to use them for the weight
    * 1 mm oversize rollers weigh 2.5 grams more than the standard roller
    * 2 mm oversize rollers weigh 5 grams more than the standard roller
2. They give you more belt squeeze for a better hole shot.
3. The oversize rollers will raise your rpm's allowing you to run your clickers in a lower position.  Having your clickers in a lower number keeps your ramp angle shallower for better acceleration.  Lower clicker numbers also give you more usable numbers available for upward adjustment.
4. Last and certainly not least, they cost much less than the stock rollers.

Thunder Shift Yamaha Rollers

1. Tuning component for stock clutches or when using Heavy Hitter Arms.

2. Hardened steel rollers are bushed and ISR stock legal.

3. Two sizes offers tuning for all models.

4. Smaller size increases force of cam arms, larger size decreases force.

5. More economical than helixes with more consistent results.

6. Fits all late model Yamahas with 9mm (SRX, Viper, Venom, Rage, RX-1, Warrior, Vector, Mtn models, and new 06 models).

7. Sold in sets of three with installation instructions.