Ducati Sporting Club UK > DesmoDue Race Series > DesmoDue - General Questions and Chat > FAO Tonio600, Fork spacer

[Paul James]

Originally Posted by skidlids

I do have a formula that I have used for 15 years where by you can work out a single rate spring from its measurements,
you need to input the spings OD, the OD of the wire the spring is formed from and the number of free turns.

I also have another 15 year old formula I use for selecting springs rates, mainly used when I was building specials.
This uses information
Such as the bikes weight bias and overall weight of bike and rider, amount of suspension travel available (shock or fork stroke), linkage ratio (plotting the curves is fun) and g force the wheel is likely to encounter (size of bump and speed at which it hits it)

That is fine if all the springs are made of the same steel Kev but if the actual material spec is different it puts the calculation out of the window if you merely use the physical dimensions within your calculation. That's why I suggested some simple practical tests of the springs you guys may have access to.

It is a minefield when you start to add on the imponderables like reaction time, severity of bump etc. so like most things in life the theory is interesting and gives a starting point to work from, in reality its always going to be what it feels like when you are out there riding it innit