Primary spring...opinions?

[Old Scud-doo]

Just to throw a wrench into what everyone has been saying, a 140/330 spring loses aournd 10 to 20 # of pressure when it gets over 200 degrees. Was told it could actually be more than that but for our purposes I will under estimate. This why you lose performance when your clutches are hot. Titanium only loses about 3# at the most. So your steel 140/330 is closer to 120/310 when hot. Yes your spring rate is consistent but your rpm are way under target.

I have noticed it and I am sure other have too. I am hoping that the 120/340 titanium spring will perform better hot than a 140/330 steel spring will when at the same temperature. I will know more one this 90 degree weather takes a dive and we get some snow. Thanks for all the input and opinions.

 

[LoudHandle]

Just to throw a wrench into what everyone has been saying, a 140/330 spring loses aournd 10 to 20 # of pressure when it gets over 200 degrees. Was told it could actually be more than that but for our purposes I will under estimate. This why you lose performance when your clutches are hot. Titanium only loses about 3# at the most. So your steel 140/330 is closer to 120/310 when hot. Yes your spring rate is consistent but your rpm are way under target.

I have noticed it and I am sure other have too. I am hoping that the 120/340 titanium spring will perform better hot than a 140/330 steel spring will when at the same temperature. I will know more one this 90 degree weather takes a dive and we get some snow. Thanks for all the input and opinions.

If your clutching is anywhere near 200 degrees F. Your clutching is all F'd up. I don't like to see it much over 100 degrees F. I do like the consistentcy of the TI as well as the lighter weight though. Good quality springs are worth the investment, IMO!

 

[Old Scud-doo]

If your clutching is anywhere near 200 degrees F. Your clutching is all F'd up. I don't like to see it much over 100 degrees F. I do like the consistentcy of the TI as well as the lighter weight though. Good quality springs are worth the investment, IMO!

You are probably right. I have never ever checked to find out how hot they get. How hot is normal/safe? I just used the numbers that RCS used when I spoke with them. I know when in deep snow and really working the sled hard at low speed the peak rpm does drop. I am assuming that is because of the temps having an effect on the steel springs.

 

[LoudHandle]

You are probably right. I have never ever checked to find out how hot they get. How hot is normal/safe? I just used the numbers that RCS used when I spoke with them. I know when in deep snow and really working the sled hard at low speed the peak rpm does drop. I am assuming that is because of the temps having an effect on the steel springs.

I'm sure there are others that can speak more intelligently to these points than I; I do not consider myself an expert by any means. I like to be able to put and leave my hand on either clutch. Any hotter is too hot in my opinion.

I attribute the heat to two major changes in the last ten years; First,sleds come geared too high, so you never use the whole clutch. This has caused a trend to bandaid the problem by running higher spring rates and helix angles in the secondary to achieve the extra clamp load on the belt to reduce slippage (the primary cause of all the heat). Which tends to fight the up shift and the heavier weights hurt the back shift.

I'm still old school, clutch wise. Softer springs, lighter weights, which allows shallower helix angles and still have good up shifts and back shifts. But requires custom helixes due to the popular trend, as stated above.

I do not have a PRO setup yet but will be testing this winter, so Until proven otherwise, that is the direction I'll be heading.

 

[Sheetmetalfab]

I'm sure there are others that can speak more intelligently to these points than I; I do not consider myself an expert by any means. I like to be able to put and leave my hand on either clutch. Any hotter is too hot in my opinion.

I attribute the heat to two major changes in the last ten years; First,sleds come geared too high, so you never use the whole clutch. This has caused a trend to bandaid the problem by running higher spring rates and helix angles in the secondary to achieve the extra clamp load on the belt to reduce slippage (the primary cause of all the heat). Which tends to fight the up shift and the heavier weights hurt the back shift.

I'm still old school, clutch wise. Softer springs, lighter weights, which allows shallower helix angles and still have good up shifts and back shifts. But requires custom helixes due to the popular trend, as stated above.

I do not have a PRO setup yet but will be testing this winter, so Until proven otherwise, that is the direction I'll be heading.

When are you going to put up some pictures of you're project?

 

[LoudHandle]

When are you going to put up some pictures of you're project?

I had to reply via my phone, SW and my laptop are at odds with each other lately. No other website does it but SW locks it up, I have to power it off and start over. Anyway after typing a long version twice and losing it, here is the short version; I need a short course in posting pics. Hopefully whatever is causing the lockup gets resolved soon. Otherwise may have to use BCR's instead.

 

[CROW]

Some great info in this thread.