Helix choice

Mac

Mac

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Joined
May 2, 2003
Messages
764
Location
New Jersey
Im looking to purchase a new helix for a 780. Thinking 53/45
I see two choices. Both Multi angle. Below is the description of both.
Does anyone have opinions?

The “R” (radius) series helixes for Yamaha from Dalton features a short duration initial angle, 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.

Or Pioneer
BILLET MULTI-ANGLE HELIX'S

A multi-angle helix is designed to improve your sleds acceleration while maintaining back-shift. The initial angle of the helix is increased to compensate for the significant torque increase of the newer two stroke engines. As the RPM’s and speed increase, the helix angle drops, allowing for improved back-shift at higher speeds where the torque increase is not as significant. The first number is the initial angle, the point at which the helix is placed with the clutch in the closed position. The second number is the full shift angle, the helix angle changes at a steady rate until reaching this angle at full-shift. The quality of these helixes are equal to or better than any on the market at a lower price.

Available angles:

43/39, 45/39, 47/39, 48/40, 52/40, 45/41, 47/41, 49/41, 51/41, 48/42, 47/43, 49/43, 51/43, 53/43, 49/45, 51/45, 53/45, 51/47, 53/37

Price: $84.95 each, includes bushing
 
i never tryed heavy hitters but i tested every helix you listed. you also have a 780. i did not. i can,t come into this post and point to one to get and bam, your all set. maybe don can. 3:16 (yammie tony)
 
I used to run a Dalton 50/40 (not the R cut) and heavy hitters with my 780. Back shift wasn't the best in the tight trails but it hauled on the flats. One thing I've found though with the heavy hitters is there's a few different versions out there. So one helix might not work from one style to the other.
 
what helix are you using now? to run 91-9300rpm on top you might need a bit shallower finish,unless your weights are set up light. The advantage of running a bit shallower finish is you can run less spring tension in the rear clutch and it will go faster. The smaller angle automaticlly provides more belt pressure from the smaller angle,needing less spring tension to hold the belt from slipping.
 
I'm running a helix from an RX1. Its a 51/43 and does not seem to perform. I remember reading on TY the angles of this RX1 may not be accurate.
I'm running a green secondary. My secondary clutches were fully shifted testing last year. Im gunna gear up one tooth.
I run CPR pipes 9100 off the line slowly increasing to 9300.
My heavy hitters are 65 gram base.
 
ok, now we have some more info to work with. Those rx1 helix only shift like a 48 start and end up about a 42 or so finish. Yes, it isnt a super aggressive helix. If your running the right rpm then youd need to keep the finish angle of your new helix around 42 degrees then. If you change the chaincase gearing to a taller gear that will lower your rpm. So having said that... a 45 degree finish angle will lower your rpm even more, youll not be anywhere near 9100rpm more like 8600rpm or so on a guess.

In my best "guesstimate", youd want something like a 52/42 aftermarket helix, that will be way more aggressive on the upshift and will yield good topend with the rest of your set up still needing to turn 9100-9300rpm. Your green sec spring will work well with that, likely around 70-80 twist depending on how good of traction you get or how wet and heavy the snow is, you can always turn it down in twist and get more topend.
 
Thank You Mr Viper as always for your experience. I'm going to order a new helix tomorrow. Hopefully some cold weather will freeze my local lake for testing. Do you have any thoughts on MPH at 1000 feet for a 780 jetted to perfection? I run a pretty lean setup on 50/50 race fuel/premium, bored carbs, 24 cc mega power, CRP pipes and cylinders, 50 squish.
 
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