"Y" Series helix for Yamaha:
Extensive machining to be lightweight like the OEM castings, but with the attractive strength of solid billet aluminum. Helixes for Yamaha use the prefix "Y" before the angle for the part number e.g. Y50/40
"YSR" Series helix for Yamaha:
The 2017+ Yamaha Sidewinder model comes with a roller secondary. The roller secondary clutch is different than other previous Yamaha models with button secondary, and uses a different helix. We have a wide selection of angles available for tuning. The stock helix when with the stock secondary spring on a Sidewider is close to coil bind (very close to being stacked coil to coil when at full shift of the clutches). Dalton helixes now have more relief depth in the spring pocket for those concerned with that. Dalton helixes feature solid billet construction, accurate machining and angles the same as Yamaha. Dalton roller helixes for this model have "YSR" prefix for the part number.
"R" Series helix for Yamaha:
The “R” (radius) series helixes for Yamaha from Dalton features a short duration initial angle, and radiuses into what is mostly a straight angle helix (second angle). This style of cut is a favorite of some clutch tuning professionals and is quite effective at controlling initial over-rev while still maintaining the characteristics of a straight helix.
Note: Images shown are for reference only. The actual product may vary.