How to set up the suspension on your mountain bike
By Matthew Sklar, June 2021
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Setting your suspension up correctly can unlock the real capability of your mountain bike; but get it wrong, and you're wasting time, energy, and all that lovely ability your bike has. Here, guest author Matthew Sklar takes you through the steps.
Your new full suspension mountain bike is pretty sweet, huh? Maybe you bought it brand new at a shop, maybe you snagged it second hand for a great deal, either way, new bike day is really exciting, and always worth a celebration. But, once you’re done admiring it, it’s time to actually set up your new bike, and that’s where things can get complicated. Setting your seat height is easy, but that shiny new suspension with all the knobs and dials? Well, we don’t blame you if you don’t know where to start. Don’t worry though, with this guide we’ll break down how to set up your mountain bike suspension simply and easily so that you can get the most out of your new bike.
Why adjust your suspension?
Why is it worth taking up the time to set up your suspension? Well, a bunch of really talented engineers spent a bunch of time and money developing your bike and suspension to be highly adjustable so that it can help compensate for a wide range of riders and trails. It’s not meant to be a one-size-fits-all product. Instead it’s designed to be tweaked by the end user (you) to most perfectly match what you’re trying to get out of the bike. So if you’re not setting up your suspension properly, you might not be using your bike to its fullest potential.
Beyond that, setting up your suspension can help give you insight into your own strengths and weaknesses as a rider, and how you can use your bike to help you compliment and compensate for them. So let’s turn some knobs! A note, not all forks and shocks have the same level of adjustability. Normally more high-end and expensive suspension is more adjustable. Regardless, these principles will help you better understand your bike.
What you’ll need
To set up your suspension, you’ll need a few things. Obviously, you’ll need your bike, you’ll also need a shock pump, if you don’t own one, most shops carry them, and you can often rent or borrow them from the shop as well. Finally, you need a section of downhill trail that’s typical of what you usually ride. You want a section that’s a couple of minutes long that has a little bit of everything you usually run into out on a ride. This will be your testing ground as you tweak your suspension.
Finally, check to see if there’s a guide for your specific bike and fork already available online. Most manufacturers will publish a guide of ballpark air pressures and settings to help you get started, and suspension manufacturers like Fox and RockShox actually have tools online where you can enter your height, weight, and riding style and they’ll give you suggested settings. So if you have those tools available to you, start with them. It’s much better than standing standing around in the woods shaking your bike helmet in confusion or frustration.
Set your sag
The first step to setting up your suspension is setting your sag. This is the distance the suspension moves when you’re just standing on the bike, not running over any bumps. This allows the wheel to travel down to suck up ruts, instead of just pushing up over bumps. Usually you want to run between 20% and 30% sag. So when you’re geared up, standing on the bike, the suspension should sit just under a third of the way into its travel. It’s helpful to have a friend here, to look at the fork and shock while you stand on the bike, and eyeball how much sag you’re getting. Too much sag, and you need to add air, too little, and you need to let it out. Actually using a ruler, or the built-in markings on your suspension can help you be more precise. Take your time setting your sag, this is the starting point for everything else you’ll do.
Setting your rebound
Once you’ve set your sag, write down the psi your shock pump reads at that sag. That number will be useful if you ever need to set up your suspension again. Then it’s time for the fun part - rebound. There’s usually a rebound knob on the bottom of your right fork leg, and somewhere on your shock. Start out with the rebound fully closed (all the way at the “slow” side, or the ”+” side). Ride your sample section of trail like this, does the fork feel dead and sluggish? It should. Start spinning the knob out a few clicks at a time, testing with quick laps on your sample trail. Once your rebound gets too fast, you’ll be able to tell because the fork will feel bouncy and out of control over bumps and roots. But if it’s too slow it will feel sluggish, and the suspension will pack down under multiple impacts, compressing further and further because it’s not bouncing back fast enough.
Setting your compression
Once your rebound is dialed, note how many clicks from closed your ideal setting is, this will be helpful later. Now it’s time to set up your compression. Compression damping has a similar impact to air pressure, it changes how much force it takes to move the suspension, but it does so in the middle of the suspension’s travel, instead of all the way through it like the air pressure does. Basically, this allows you to dial in how much “wallow” you have in the mid section of the fork.
You want your suspension to feel very supple high in its travel, near that sag point, but then be more supportive under bigger hits so the suspension doesn’t dive when things get steep and gnarly. So start with your compression knob fully open, and then ride your test lap a few times, adding clicks until the suspension feels predictable and supportive in that midsection, but isn’t harsh off the top. Too much compression and it will feel dead throughout the stroke, too little and it will feel like there’s no platform to push into.
Once your rebound and compression are set
Go ride your bike! But don’t be afraid to continue to experiment with your suspension settings. You’ll grow and evolve as a rider throughout the season, so adjust your suspension to work with you. As you push harder you might want to run less sag, faster rebound, and a little more compression. Or you might head out on a trip somewhere new that requires different settings. Don’t be afraid to experiment. As long as you write down your original settings you can always return to them. Just make sure to only tweak one setting at a time, that way you can tell what’s making the bike feel different.
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About the Author
Guest author Matthew Sklar is
All credits: Matthew Sklar, 2021