[- seb]

Clearly I don't clean my bike enough, and as such all of the markings have worn off all but one of my springs.

So, what rate are the mystery springs?

All are steel, no titanium ones.

 

[partsbara]

500, 650 and 700


how sure am i - 3 % positive

 

[oly]

what do we win?

 

[Jeremy R]

500, 550, and 600

 

[- seb]

I came to the conclusion that the rate would be:

proportional to square of thickness
proportional to cosine of pitch
inv. proportional to wire length

As such worked out that they're

450, 300 and 450 lb/in

Which definately seems wrong so my thinking must be flawed

 

[- seb]

Just seen how much the YM can vary for different grades of steel. Fck this for a game of soldiers

 

[S.G.D]

i thought this mechanical challenge was going to involve a huffy.

~SGD

 

[SilentJ]

Just seen how much the YM can vary for different grades of steel. Fck this for a game of soldiers

Yep...I got pretty much the same numbers as you...it must be a YM issue.

I get:

k2=456.6
k3=292
k4=453

The eqn I used is proportional to the fourth power of the diameter of the coil, inv. proportional to he number of active coils, and inv. proportional to the cube of the spring diameter. (with a constant or two thrown in for good measure)

K= [(wire dia^4)*(steel constant)] / [8*(# coils)*(spring dia^3)]

I used 12 000 000 for the steel constant...calculating backwards, I get 12 496 561 for a steel constant with the 400# spring given.

 

[- seb]

interesting how close our results are given the totally different formulaic approaches!