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Discussion Starter · #1 ·
I wondered what TI spring would best deliver stable platform features for aggressive CC riding; my bike is a Turner Burner with the XR rockers. These rockers change the leverage ratio at the shock (though I do not know numbers specifically, the feeling at the shock is significantly different and I have used higher air pressures in my Swinger3 to produce a like feeling in compression). I weigh 180 all suited up. I am using a Romic shock that is 6.5x1.5".

Any advice? I find the #600 TI spring I have now to be too soft. Yet the #600 stell spring is said to be adequate to my weight/riding profile.

Thanks for any help
 

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Tall said:
I wondered what TI spring would best deliver stable platform features for aggressive CC riding; my bike is a Turner Burner with the XR rockers. These rockers change the leverage ratio at the shock (though I do not know numbers specifically, the feeling at the shock is significantly different and I have used higher air pressures in my Swinger3 to produce a like feeling in compression). I weigh 180 all suited up. I am using a Romic shock that is 6.5x1.5".

Any advice? I find the #600 TI spring I have now to be too soft. Yet the #600 stell spring is said to be adequate to my weight/riding profile.

Thanks for any help
600 lbs/inch is the same whether the spring is Ti or steel.

Check your sag. I'm not an expert in XC setups, but I'd guess you want it to be around 25%.
 

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carpe mañana
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Tall said:
I wondered what TI spring would best deliver stable platform features for aggressive CC riding; my bike is a Turner Burner with the XR rockers. These rockers change the leverage ratio at the shock (though I do not know numbers specifically, the feeling at the shock is significantly different and I have used higher air pressures in my Swinger3 to produce a like feeling in compression). I weigh 180 all suited up. I am using a Romic shock that is 6.5x1.5".

Any advice? I find the #600 TI spring I have now to be too soft. Yet the #600 stell spring is said to be adequate to my weight/riding profile.

Thanks for any help
The Burner with X rockers (3.6in of travel) has an average leverage ratio of 2.4:1 (3.6/1.5). With XR rockers it goes up to 2.667:1 (4.0/1.5). This means that your weight is multiplied as it acts on the shock. If you were ok with the 600lb spring before, you will need a 650 or 700lb spring now, depending on preference. This is why you had to add air pressure before - to increase spring rate to compensate.

_MK
 

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Discussion Starter · #4 ·
Thanks MK_ . I understand how you arrived at those compression ration figures. I want to understand one more: Should Titanium require less or more preload to achieve x% sag as a steel counterpart?

My stock Romic #600x1.5 measures 95mm while my Ti aftermarket spring measures 80mm.

Thanks
 

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carpe mañana
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Tall said:
Thanks MK_ . I understand how you arrived at those compression ration figures. I want to understand one more: Should Titanium require less or more preload to achieve x% sag as a steel counterpart?

My stock Romic #600x1.5 measures 95mm while my Ti aftermarket spring measures 80mm.

Thanks
The amount of preload ought to be the same. Typically the titanium "rod" which composes the winds of the coil is thicker than the steel. That together with the spacing between the winds ultimately dictates the size of the spring, or how tall it is.

Preload is related to the thread on the body of the shock. Preloading the Ti spring x amount of turns produces roughly the same effect as x amount of turns on the steel.

There is another factor in all of this which might help explain the observed difference in behavior between the two springs. The factor is quality control. A mass produced spring is bound to vary in its actual rating from the intended value, say 600lb. How much it varies, it depends on what the manufacturer allows. Fox, for example, allows 15%. Yikes! This means a 600lb spring could be a 510 or 690 or anything in between. Romic's tolerances are tighter. I'd imagine RCS's as well. Your best bet would be to go to a motorcycle parts store and see if they have equipment to rate your spring, it will remove any unknowns as to what the spring actually is.

_MK
 

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It amazes me how many people still think that a ti spring with a certain K value should somehow be different than a steel or plastic or any other material spring with the same K value. If one looks at the simple math involving spring constants, there is no variable assigned to material what so ever.. sorry if that seems harsh..just seems like someone posts this every two weeks or so.

any ways, the RCS springs are significantly tighter tollerance that than say a fox or other stock steel spring.
 

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davep said:
It amazes me how many people still think that a ti spring with a certain K value should somehow be different than a steel or plastic or any other material spring with the same K value. If one looks at the simple math involving spring constants, there is no variable assigned to material what so ever.. sorry if that seems harsh..just seems like someone posts this every two weeks or so.

any ways, the RCS springs are significantly tighter tollerance that than say a fox or other stock steel spring.
That probably comes from comparisons with Fox springs that have really wide tolerances as MK pointed out. People think they're feeling some difference between Ti and steel when really they're feeling two different K's.
 

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Discussion Starter · #8 ·
I have a #600 spring for trade

Thanks for your later replies. I have no idea what K is. Believe me when I say that I ride my bike and do not have any engineering or physics knowledge.

But, though I enjoy the riding, I wrench on my own bikes and keep them running well for years.

I had a simple question that needed a simple answer. I think that it pays to speak in terms most people can understand rather than trying to show us all what a smart dork you are.

Anybody want to trade a #700 ti spring for a #600 ti spring (fit for Romic)?

Thanks one and all, peace.
 

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Tall said:
Thanks for your later replies. I have no idea what K is. Believe me when I say that I ride my bike and do not have any engineering or physics knowledge.

But, though I enjoy the riding, I wrench on my own bikes and keep them running well for years.

I had a simple question that needed a simple answer. I think that it pays to speak in terms most people can understand rather than trying to show us all what a smart dork you are.

Anybody want to trade a #700 ti spring for a #600 ti spring (fit for Romic)?

Thanks one and all, peace.
You actually do know what 'K' is as you keep referencing it....the K value for your spring is 600 lb/inch. No one is trying to show how smart they are, or can be, it is just that this same question comes up every couple of weeks/months. You could have searched, or when given a term that you are unfamiliar with, looked it up (google), rather than calling names.
 
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