RIGHT NOW I'M RUNNING A 66/.46.42 AND IT TOPS OUT REALLY WELL.VERY HAPPY WITH IT BUT SEEM I'M LOSSING A LITTLE IN MID RANGE, MY QUESTION IS IF YOU GO TO A STEPPER ANGLE LIKE A 70 STARTING ANGE WILL YOU LOSE TOP END? AND IS THE .46 IS THIS THE FINSIH ANGLE? AND THE .42 IS THE MID RANGE ANGLE? SO IF I GO TO A 66/.46.46 WILL I GET A LITTLE MORE PULL IN THE MID RANGE? OR IF I GO WITH A 68/.46.46 WILL I GET MORE LOW END AND MID RANGE AND LOSE ALITTLE ON TOP END? TRYING TO FIGURE OUT HOW THESE ANGLE WORK. THANKS
CAN SOMEONE EXPLAIN HELIX ANGLES?
- Thread starter river
- Start date
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chunkysoup
Well-known member
66/46.42 = 66 is ur initial angle, the steeper the angle the faster the upshift. 46 is ur final angle and .42 is the duration,length in inches it takes to go from a 66 to a 46!
If you go to a 70 initial angle it will want to upshift very fast and the belt will suck into the secondary causing the sled to bog down from the start.
If ur pulling the 66 pretty well i would leave that alone. What u could do is lengthen the duration and drop a little final angle. U would be doing pretty well with a 66/44.46!
Ok thanks, but if I read that right ,going with a 44 finish angle, would raise my rpm's and they are good right now. was wanting a little more mid range would a 66/.46.46 give me that?
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chunkysoup
Well-known member
reason i said to use a 44 was because it wont shift out as fast in the midrange letting u keep ur rpms! what secondary spring r u running cuz u could run the 66/44.46 and run a little lighter final rate spring and keep ur rpms the same?
I have the black/red spring in the secondary someone else say I should try a 62/.46.36 ?
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chunkysoup
Well-known member
You can do what u want but i would try the 66/44.46 before i tried a 62/46.36 unless u just have it sitting around and can put it in and try it. then i would say go for it but helixes arent cheap in my opinion. The steeper the angle u can handle without bogging the better. the black/red (155-222)spring should be good for that and u mite even want to try a red/black (140-240) or a black/purple (160-240). these 900s like steep helixes and soft springs! if it does change ur rpms u can always adjust that with a primary spring. Adjust shift with ur secondary and adjust rpm with ur primary! thats what ive always been told!
We need more info to help you out. Where do you ride, what elevation and what type of riding?
Even for the 9, a 66 could be to steep depending on your answer to the above question.
As an example, I ride at between 4 and 8k feet, lots of boondocking in deep snow (most years) and I prefer the stock helix (64 38 36) with a red black spring. For me, it's all about the backshift and I want it quick when I need it. This helix aids in spinning the track a little bit quicker initially over the 66.
You would do better to look towards your primary to control RPMS because the helix, with your gearing and track as it runs in the snow and depending on snow load will fluctuate, rpm wise and track speed wise. It's gonnna vary from day to day depending on snow conditions.
I ride in Michigan 0-3000 ft. its a 900 switchback 144 track with all the slp mods on it . I have the epi belly buster 78's in the primary and the black/green spring and the 66/.46.42 helix with the black /red spring and derlin washer.I get really good top end speed but I'm loosing in the mid range and take off . I ride mostly trails and some off trail. flatlander here. thanks for the help .
Okay...well I think you've just about got it nailed for where your at. If you make a change you will probably see a loss in another area. With that steep initial angle you will be slower off the line, but as you stated, you do gain ground in the top end when she is stretching her legs. Conversly if you go to a shallower initial angle, you will be quicker in the low and mid but slower at the top....and everyone will catch you....it's a pick your poison on any given day kinda deal. Good luck.
Ok thanks for your help, that helps me understand the helix's a little better.I was thinking if I went with a shallower initial angle like the 64/.46.36 would I not still have the same top end? as the finish rate would still be the same.and get there a little quicker with the .36 than the .42 that in the 66/.46.42
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You are correct in your thinking...
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