Primary spring - NEW - 175/360

[Dynamo^Joe]

After a year trying to get this spring made, I finally got it done early December 09.

Known BRP primary springs 160/350 and 200/350 - I have never been able to find a 180/350 something with the start forces in between the 160/xxx and 200/xxx so then after campaigning a few spring mfg'rs finally got someone convinced to make this spring.

The dimensions of the TRA primary clutch spring cavity would not allow an exact 180/350 with present spring wire capacity so the closest that could be made was 175/360 = WOO! haha

The whole point of the exercise was to be able to have more spring force at track speeds being used in mountain riding without having an excessive high final spring final force. Tuners like the force that the 200/xxx provides in usable track speeds however the engagement rpms for them is too high, many at 4200.
The 160/350 can reveal fluctuating rpms in bottomless powder.
The 160/380 raises the forces at usable track speeds in snow, however can over rev on the road/trail.

Note in the spring chart below the differences in spring forces at an example 19:45 gears for 8150 rpms.

At 45 mph track speed the;
160/350 has approximate 255 lbs force.
175/360 has approximate 270 lbs force.
200/350 has approximate 277 lbs force, however with high engagement rpms.

160/380 has approximate 275 lbs force, however high final force that can contribute to high rpms on the road, forcing one to clicker down 1 or 2 numbers.

The Violet / White stripe is now available at the Revzone through this form for $35 Canadian bones+ship.

 

[chrispy]

This is the spring that was sent to me in my kit I recently installed in my sled. I have nothing but great things to say about it. On the whole, the complete kit is amazing and everything worked just as Joey explains it. The engagment was within 100RPM of stock and there were very minor fluctuations in RPM while climbing in inconsistant snow conditions, but would almost instantly recover the lost RPM unlike with my stock configuration. I would jump from 8100 to 7900 to 8000 to 7600 as so on. The back shift is phenomenal thus producing almost instant throttle response. Thanks again Joe, great work!