Coil springs have always been the best suspension and they're making a come-back.  But they have one big downside: you've got to get the spring-rate right.

The methods for getting spring rate right have historically sucked.  You can spend a fortune on springs (up to $300 each) and swap them out until you find happiness, or find someone else and copy them.  But this isn't guaranteed either.  If your damping is wrong even the right spring will feel wrong.

Many have attempted spring-rate calculators; based on sag, leverage ratio or straight out hocus-pocus.  No two would agree.

Here at Shockcraft we do things differently.  We brush aside all the black art BS and apply physics and maths the way it should be.  It's called Engineering and it's amazing that this hasn't been done before!

Working from the ground up we calculate sprung and unsprung weights and the spring rates required to drive those leveraged weights at the frequencies that bike suspension needs.  Both fork and rear shock spring rates are delivered.

From all this work we have published three spring-rate calculators.  The first is very simple and it's free to use.  Simply enter your weight and it spits out a front spring rate.  This calculator is based around a 160 mm Enduro/Trail bike using a 56 mm stroke shock with a 65 deg head angle.

If you want to get serious, pay a small amount and you get into our advanced bike spring rate calculators - one for Rear Spring Only (lower price) and one for both Front & Rear Spring Rates.  These let you tweak everything from wheelbase and head-angle through shock stroke and unsprung weight.

Note: we have recently changed our bike spring rate calculators so that the simple calculator only provides fork spring rate.  We now have two Advanced Bike Spring Rate Calculators - one for Rear Spring Only (lower price) and one for Front & Rear Spring Rates (higher price).