Setting up a dirt bike for a rider is a very individual ritual. Even though there are plenty of foundational starting points, every rider should still test and evolve their setup for their riding style, terrain, and enjoyment. Brian Storrie helps me understand the baseline settings for dirt bike setup so we can then evolve the GasGas EX350F for my 2025 challenge of taking on the National Enduro Series.
Setting Free Sag and Rider Sag
Setting the sag on your dirt bike is very important. There’s a range of numbers, typically set in the manual, that the manufactures want you to be in for the bike to work to what they believe will be the best performance and handling. These numbers are just that though, a range. Every rider is different, along with the terrain they’ll be riding in.
The free sag for the GasGas is recommended to be set at 35mm. This is the number the bike should be sitting at without a rider on it, only the weight of the bike compressing the suspension. If this number is too small, compared to rider sag, a heavier spring may be needed. If this number is too big, compared to rider sag, a lighter spring may be needed.
The rider sag in the manual for the GasGas EX is set at 102mm. The rider sag for the MC version of this bike is set at 105mm. Due to Brian Storrie’s history on this motorcycle, we’re working toward 105mm as our number to range around.
As the rider, you’re going to want to be as close to completely geared up as possible when setting your sag. What are the non-negotiables while riding, have those on when setting sag. Helmets are light enough these days, you can opt to set sag without your helmet on. Just stay consistent as you check your sag for future rides.
When we first checked the free sag, the bike was at 41mm. The rider sag netted out at 104mm. Storrie wanted to add some preload to the spring because he believed, with his years of experience, that adding preload would be ok for me and my riding style with the EX350F. After adding a full round of preload, I tested the bike and it felt really good, nothing noticeable stood out. Storrie said this is a good way to test. If something noticeable stands out right away after a change, was it good or bad? If it affected you in a negative way, there’s no reason to stay there just because a manual tells you to. If you didn’t really notice, it was probably a good change.
If you need a sag tool, the one we used in the video is the Motion Pro Sag Tool, and the Slacker Sag Tool Storrie mentioned is another great option. We made a Slacker setup video if you want to see it in action..
Setting Handlebar & Lever Position
Regardless of what you’ve done in the past, with a new bike it’s always a good idea to start at baseline. As you ride a test loop, or track, you can start to make changes from those baseline settings toward what you think you might prefer from previous bikes.
Baseline for handlebar positioning should be set at the zero mark on the bar in the handlebar clamps. Levers should be angled in a way that you can easily reach them while standing, or sitting. If you know you sit or stand more, adjusting the angle for that makes sense. Just remember to test and see what you feel actually works best versus making assumptions.
Lever perch placement on the handlebars should be placed so your pointer and middle finger can fit into the pocket of the lever. This should be setup when your hand is placed in the middle of the grip. As you feel your hands, or body, moving inside or outside during testing, you can adjust the lever perch so you’re grabbing the lever pocket correctly while riding, not just sitting on the bike.
As before, you’ll notice poor adjustments quickly. If you don’t notice a change, it may be moving in the correct direction. Use lap times to determine if it helped you ride faster, maybe without even noticing how effective it was.
Setting Rear Brake Pedal Position
If your rear brake pedal is too high, and you’re lifting your foot off of the peg to press the pedal, you’re turning the rear brake into an on and off switch. You won’t have the ability to modulate as well, and your heavy boot bouncing down the trail will just drive itself onto the pedal.
The more you sit while you ride, the lower your pedal will probably need to be. As you begin to stand more, raising your pedal height will work better for the standing position.
For four stroke riders who have an issue stalling their bike a lot, Storrie suggests lowering your brake pedal some. He mentioned to me there’s a good chance some of my early stalling issues could be due to the rear brake engaging sooner than I was ready for it too, causing the four stroke to stall.
Four Stroke Thoughts So Far
The GasGas EX350F is meant to be ridden fast. I was blown away by the power from day one. As I am getting more comfortable on the bike, it continues to prove to me that this bike was meant to be raced.
Every day on the bike I get a little bit better at using the clutch, and keeping the stalling to a minimum. Every time a stall happens now, I stop and think about what I was doing, what I was riding, and why I stalled the bike. I’m not convinced that just because it’s a four stroke that it stalls. I’ve already started to smooth out my clutch use, and power delivery, causing faster lap times and minimum flame outs.
I don’t think this bike is fun to trail ride on. When Liam and I have gone out to ride together I don’t like breathing down his neck with this barking four stroke. In those scenarios with Liam, and the days of play riding, I do miss the two stroke. The two stroke seemed to exude a good time, where the four stroke wants you to ride fast AF.
All that to say, it’s the perfect bike for me this year! I believe the EX350F is going to be a very competitive enduro race machine. I may not win classes, but I know I’ll ride as fast as I can, while wearing a wide grin beneath my helmet.
About Brian Storrie
Over 25 years ago, I heard a great tuner say “The best you have ridden is the best you know”. That still holds up today, and I have spent these 25 years helping rider’s find a better feeling with their bike.
I also enjoy helping rider’s and their crews understand the physics of how the bike and rider need to work together for the best result.
I have worked with MX and Offroad rider’s of all levels from beginner to national Pro’s.
I am still an avid rider/racer who enjoys MX and Offroad racing regularly, and if you hire me to help you with riding lessons or bike setup, don’t be surprised if I’m on track whenever you need a break!
I’m also proud to say that I am an 18 time Team USA ISDE rider, and a Glen Helen Over 50 expert World MX champion.
Send Brian Storrie a message on Facebook or Instagram and let’s get some seat time!
1 Comment
These bikes are meant to ride fast (and most gears rev out way more than you'd expect - took me a few years to discover just how much!). But they also ride well in the woods a gear high (as long as you prepare on the clutch side), and while I miss two strokes on super gnarly terrain, the 350s have been fantastic for moto/enduro/woods racing. They are a great counterpart to the 300 two stroke audience, although they are on the other side of that coin (aka a bit more aggressive overall).
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