To be used as a guide to spring selection. The spring rates recommended give a sag of around 28 to 30%.
Enter your details below and click 'Get Spring Results' and the correct spring rates will appear in the 'Recommended Spring Rates' fields below. If you need help getting these figures, please read the text below.
How do I determine the stroke of my shock?
The stroke of a shock refers to the amount of travel available, and can easily be measured by taking the distance from the main body of the shock to the end of the shaft or damper body, depending on whether you have a coil or air shock. If you decide not to measure your shock stroke, you can find it on the manufacturer's website, or by phoning us. If you refer to the manufacturer's website, you will probably be given a figure like '8.75x2.75”', where 8.75” refers to the overall length of the shock, and 2.75” refers to the shock stroke. The figure you measure should be between 1.25 and 3.00 inches. If you get another figure, you're probably measuring the wrong part of the shock.
NB. Fox mark springs by quoting the maximum travel the spring will go to before it becomes coil-bound. e.g. 1.65 = 1.5" stroke, 2.35 or 2.38 = 2.0" or 2.25" stroke, 2.8 = 2.5" or 2.75" stroke & 3.25 = 3.00" stroke. BOS mark their springs by quoting the free length e.g. 140 = 2.5" or 2.75" stroke, 160 = 3.0" stroke & 180 = 3.5" stroke
How do I determine my wheel travel?
The term “wheel travel” refers to the distance a wheel would move from the shock being fully extended, to being fully compressed. The easiest way to obtain this figure is probably to refer to your manufacturer's website or to give us a ring. If you're feeling ambitious, though, you can try to measure it yourself. To do this, you'll need to measure the distance as shown in the photo below.
What do spring rate figures mean?
The spring rate is the amount of force required to compress the spring one inch, and is measured in pounds. To determine which spring you need, you'll need to know which spring rate you need, and what your shock stroke is. A spring with a spring rate of 350 is easier to compress than one with a rate of 450, and is therefore softer. Springs are usually marked with their rate, and then the stroke of shock they're designed for, e.g. "350x2.75"
NB. Fox mark springs by quoting the maximum travel the spring will go to before it becomes coil-bound. eg 1.65 = 1.5" stroke, 2.35 or 2.38 = 2.0" or 2.25" stroke, 2.8 = 2.5" or 2.75" stroke & 3.25 = 3.00" stroke. BOS mark their springs by quoting the free lenght e.g. 140 = 2.5" or 2.75" stroke, 160 = 3.0" stroke & 180 = 3.5" stroke
Why use 28 & 33% sag
These are 'ball park' figures as recognised sag for XC = 20-30%, Trail/Freeride = 25-35% & DH 30-40%. You therefore have to alter the recommended spring figure according to your style of riding.
What if I'm doing drops?
Generally you will need a 10-15% higher spring rate than recommended for 28% sag, if you're into hucking. This may mean you need 2 springs for your bike ... one for DH/Trail and one for Hucking
To buy springs, just click on your preferred brand in our shop.