Why are straight cut 49 or 51 degree prefered over progressive (55/49 - as a comparison) on 900's??
progressive helix vs straight cut
- Thread starter r9559
- Start date
preferred for what? Not exactly what sure what you are getting at?
When asked for clutch setups most guys tell you to use a 49-51 helix. No one uses progressive-dual angle helixs.
My question is why do straight cut work better that progressive dual angle ones? I my mind, I use a transmission as a comparison, straight cut is turbo 400 and a dual angle is a 700r4. The 700r4 as a lower first gear than the 400 and a better highway gear ratio (overdrive). I progressive (55/49 for example) should get you quicker out of the hole and still maintain your track speed on a hill climb because it ends at the same finishing angle as the straight cut.
If you don't know what a turbo 400 is please don't reply to this post.
old schoolers only
My question is why do straight cut work better that progressive dual angle ones? I my mind, I use a transmission as a comparison, straight cut is turbo 400 and a dual angle is a 700r4. The 700r4 as a lower first gear than the 400 and a better highway gear ratio (overdrive). I progressive (55/49 for example) should get you quicker out of the hole and still maintain your track speed on a hill climb because it ends at the same finishing angle as the straight cut.
If you don't know what a turbo 400 is please don't reply to this post.
old schoolers only
problem is most Cat helixes transition at the midpoint of the helix. This is not where the transition should be. If they had more available with a short first angle, that would be much better!!
Cat has a 55*-52* that has a short 55*. It is an older helix for a Sno-Pro.
Cat has a 55*-52* that has a short 55*. It is an older helix for a Sno-Pro.
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kidrman
Well-known member
Absolutely true. Fett Brothers and others will cut them that way but they go about 85.00 per and that is tough to swallow unless you know exactly what you want.
Answering the first post - I think it is largely preference as you will find guys adamant on both sides of the debate.
thanks for the info.
55*-52* part #0648-130 Probably only about $40 from Cat.
A
Arctic Thunder
Well-known member
Part of the problem is what you typed here. There are progressive rate helix's and dual angle. Dual angle like ccpowder said has a transition POINT and it is in the wrong spot most of the time. So as the clutch is trying to back shift it wants to hang up on the transition and won't back shift. So the dual angel helix got a really bad image right away.
Now that most people can get the "progressive" helix's cut they don't have the true transition point. it starts at a 51 and ends at a 49. So it is a straight line.
Honestly I have never had great luck with the dual angle. So I never tried a progressive. But I just purchased a new progress for my M1000 and will give it a try. This was by the direction of a couple well known turbo clutch guys. So will see.
Thunder
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kidrman
Well-known member
The 55/52 is a great helix and can be found really cheap used. I was speaking in broad terms of any angles a guy may want to try.
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