Setting your shock sag is more durable than you assume – here is the best way to do it proper

Everybody is aware of the best way to set your sag, proper? You’ve most likely accomplished it 100 instances, and there’s 1,000,000 movies on the market displaying the best way to do it. And most of that recommendation will get you into an inexpensive ballpark place to begin. However if you wish to get as shut as attainable to your optimum setting, there are a variety of things it’s possible you’ll not have thought of. Taking them under consideration will make an enormous distinction to how your bike will really feel on the path. So, listed here are six factors to contemplate when organising your rear suspension sag to get pleasure from higher efficiency.

Why solely rear suspension? Nicely there are just a few causes, however principally as a result of it’s troublesome to get a constant studying up entrance, and forks include air charts that give an honest place to begin. Wish to take this to the following degree? Why not discover out extra about tweaking your geometry to change weight stability?

There’s no magic quantity

What I need to clarify from the outset, is that setting your sag is all the time simply a place to begin. In actual fact, for those who’re solely going to remove one factor from this video, it needs to be ‘don’t fixate on a particular share’. There’s no such factor as a magic quantity. It depends upon the bike, the terrain, and your priorities as a rider. Sag is simply the start line of the journey, however realizing the intricacies and pitfalls will certainly enable you navigate in the precise path.

Sit down or rise up?

Most guides advise you to set your sag standing up within the assault place. So straight and elbows bent, and head over the stem, both leaning in opposition to a wall, or with a helper holding the bike. However there are a few issues with this. One is that it’s actually troublesome to carry a constant, repeatable place with this technique. Shift your weight barely in both path and also you’re going to have a special outcome. It’s additionally fairly exhausting to succeed in the O-ring on some designs from that place.

And while you climb, there’s going to be an enormous shift in your weight stability to the rear, and it’s possible that you simply’re going to finish up with an excessive amount of sag, poor geometry, and mushy pedal efficiency consequently. Bear in mind you’ve bought to stability the efficiency of the bike each up and down, except it’s a pure downhill bike otherwise you’re completely happy to make compromises with the climbing set-up.

One approach to obtain a extra balanced set-up is to measure your sag sitting down. This has the added benefit of not needing a helper to carry the bike.

1. Simply drop the saddle all the best way.
2. Sit on the bike on degree floor along with your toes alongside the underside bracket and your thighs pushed in opposition to the edges of the saddle.
3. Place your arms flippantly on the grips, bounce up and down, then settle along with your weight centred over the BB.
4. Attain down and push the O-ring as much as the seal and step off gently.

If we examine the distinction between the identical air strain within the two completely different physique positions, there’s an 18% hole. That’s an enormous distinction.

Sag on the shock Vs sag on the rear axle

Level two is a little more sophisticated, however positively value bearing in mind. On each suspension bike, the rear axle strikes greater than the shock. The distinction between the 2 is the leverage charge, and it adjustments all through the suspension journey. The vital level being that what occurs on the shock might not correlate instantly with what occurs on the rear wheel, regardless of what the markings in your shock physique may say.

Let’s take a look at an instance. The 2024 Canyon Spectral within the video has useful sag gradients on the shock to simplify the method. And Canyon’s makes it doubly simple by supplying you with a really exact advisable sag – which is 27.5%. We all know the shock stroke is 55mm because of the Canyon web site, so 27.5% of 55 is 15.1mm.

Job accomplished.

Nicely not fairly. Let’s work it out one other manner.

Canyon says the Spectral has 140mm of journey, so 27.5% of that’s 38.5mm. If we take a look at the leverage curve for the Spectral we will see that the leverage ratio at 38.5mm journey is 2.737 to 1. Which signifies that the rear wheel strikes 2.737mm for each 1mm of shock stroke at this level within the journey.

38.5mm divided by 2.737 will get us 14mm of shock stroke. Which implies 27.5% of wheel journey on the shock is definitely 14mm, not 15.1mm. That’s a 7% distinction. So even when you’ve got sag gradients in your shock, that’s not going to be a real measurement of sag on the axle.

Precise stroke and journey Vs claimed journey

This will get much more problematic after we take into account {that a} bike may not even have the journey it says it has. Like this Canyon Spectral right here, which has 136mm of journey, not the 140mm claimed. So to be actually correct when measuring your sag, it is advisable measure the precise journey of your bike. It’s really pretty easy, it simply takes a little bit of time.

You’ll want some straps, a spirit degree, and a tape measure.

1. Let all of the air out of the shock, and compress the bike till it bottoms out with a ratchet strap.
2. Strap a spirit degree to the saddle and measure the perpendicular distance between the centre of the rear axle and the spirit degree.
3. Or you possibly can flip the bike the other way up and measure the gap from the axle to the ground.
4. Now launch the ratchet strap and inflate the shock till it tops out.
5. Utilizing a monitor pump makes this a part of the job so much faster.
6. As soon as once more measure the gap between the axle and the extent and subtract measurement A from measurement B.

That’s your precise journey. And whilst you’re there, measure the place the O-ring ended up at backside out, to test the shock stroke.

We’ve been doing this to our take a look at bikes for a very long time, and are available throughout a great deal of bikes with discrepancies, some with as a lot as 10mm lower than marketed.

Including or subtracting air

The subsequent factor that may journey you up when organising an air shock is the adverse spring. When adjusting the air strain, you need to be sure you stability the constructive and adverse air strain in any other case you’ll get a false sag studying. Everytime you add or launch strain, it is advisable compress and launch the suspension bleed air between the 2 chambers. You possibly can go away the pump hooked up for this half. However keep in mind to take away it earlier than you’re taking one other sag studying.

In case you measure it with the pump hooked up, you’re successfully rising the amount of the shock, and you’ll find yourself with an excessive amount of sag. We’d additionally suggest all the time utilizing the identical pump to make changes, then you recognize they’re constant, even when the gauge isn’t 100% correct. And all the time jot down your settings so you recognize the place you began, and for those who change something then observe down what you modified and the way it felt – whether or not the change was good or dangerous.

Coil springs

To date we’ve been speaking in regards to the challenges of organising sag with an air shock. However when you’ve got a coil shock, your life simply bought an entire lot more durable. Why? Nicely measuring sag is far more troublesome, altering the spring charge is extra time-consuming, dearer, and fewer correct, and it’s actually troublesome to know whether or not you’re getting full journey.

Let’s speak about measuring sag first. There are just a few methods you are able to do it, however none of them are simple. On some shocks you possibly can attain by the spring and push the bottom-out bumper all the best way up the shaft to the shock physique and use it as an O-ring. That is the simplest approach to measure sag because it doesn’t require a helper, but it surely’s not very simple to measure the place of the bumper relative to the shock physique as a result of there’s so little house to take a measurement. One other approach to do it’s to measure the gap between the spring collars with the bike resting. Then get somebody to measure the gap between these two factors with you sitting on it.

As soon as you recognize the shock stroke, you possibly can work out the sag share. Alternatively you should buy one thing just like the Reverse Parts Journey and Sag Indicator. These are about €30 and have the added benefit of with the ability to let you know how shut you’re attending to full journey.

When you’ve bought a sag measurement, you higher hope it’s within the ballpark, as a result of if it’s not you possibly can nicely be ordering a brand new spring, and which means extra $$$. Sure, you should utilize the spring preload collar to fantastic tune the sag, however it’s best to solely add two full turns of the collar earlier than it is advisable get hold of a special spring.

Which is why the Springdex system makes a lot sense, as you possibly can tune your spring charge – and subsequently your sag – in 10lb increments with out including harshness by winding on preload.

The 5 key takeaways from this text are:

1. Sag is simply a place to begin and small variations in sag could make an enormous distinction to how a motorbike performs
2. Contemplate which physique place you utilize to set your sag
3. Keep in mind that sag on the shock shaft gained’t be the identical as sag rear wheel
4. Claimed journey shouldn’t be all the time the identical as precise journey
5. Shopping for a coil shock goes to make organising your suspension so much more durable