Dirt Bike Suspension vs Chassis EP.2 | Sag and Springs EXPLAINED

We're back! Episode 2 of Dirt Bike Suspension vs Chassis tackles rider sag and springs. Be sure to subscribe to the Ride JBI YouTube channel for more Race Recaps, JBI Spec, or Shop Talk Episodes!

#dirtbike #motocross #riding #moto #mx #jump #subscribe

Timestamps:
0:10 - Intro
1:51 - What is Sag?
4:58 - What is Spring Preload?
7:44 - KTM Sag
10:25 - Real World Example
17:36 - Chassis vs Suspension Adjustments
20:24 - Q&A

[LetRRoll]

Please don’t forget about enduro and hard enduro riders. If you have specific tips for those disciplines, please share. Thanks guys!!

[whitehollywood]

Can you do a whole video on hard enduro setups .. not many videos out there covering the subject. Thank you 🤙🏻

[jaywilburn]

Great series! Never figured out the suspension equation when riding in my teens-20’s but now in my 40’s, I’ve focused on getting educated and seeing the results on the trail.

I’d be interested in seeing a video on how fork fluid levels affect the stroke, impact on compression, rebound and ride overall. I’ve never really played too much with the fluid levels and would like better understand that variable a bit more.
Thanks!

[bwhaskell]

Higher spring preload is also more difficult to initiate initial compression. If I have a 6.0kg/mm spring with 0 preload, it would take 6kg to compress the shock 1 mm. If I had preload set on that same spring at 5mm, I would need 30kg of force just to get the spring to compress.

I have tried a lot of different suspension setups and for motocross I tend to prefer a little higher than normal spring rate with less preload. It makes for a more lively suspension setup, and when paired with appropriate valving, makes for a very confidence inspiring setup. Also, stiffer springs tend to absorb energy better, so in the shock that leads to a cooler running shock.

[robinbartling]

Awesome video series. Thanks for the knowledge!

[hambone]

Great discussion....Moving the ball forward in understanding of chassis and suspension concepts for riders!

[vinceseyb]

Static sag like you say gives a great reference to preload.
Unfortunately with WP you have that massive 35n/mm top out spring which fudges the static numbers. It also has a weird effect on spring "rate" through the first 18mm of of shock travel (50mm of wheel travel)
Most of the time the right shock spring will end up with 7-8mm preload to achieve the right static and race numbers.
Preload effects rebound significantly and most importantly how the bike behaves when you come off the throttle.

[manny.]

Love this series, sending my rmz450 suspension out to you guys, cant wait!

[Tukball]

Fantastic video, i have been trying to find really technical videos on suspension and chassis tuning and a lot of stuff out there is just not really in depth. I want to understand quite literally everything about my bikes suspension (2024 KX450) so i can make educated decisions on chassis or suspension changes on the fly. My goal one day is to have the tools to do my own valving and service work and not do a butchered job.

[richyoung]

It's suspension...it's always suspension! It's all your fault that I suck so bad...hahahahaha! Love you boys!

[Joe-pblx]

im kind of years ago nobody gave away suspension secrets like spring rates and 65 now and understand what its all knew something wasnt right when i rode back then but i didnt understand these days have it so good if they know enough to watch these kind of videos and ask questions at the used to race a lot at southwick in my 20's and everything was hush 1984 RM125 could of used stiffer fork springs, would of made for a more enjoyable ride and maybe i could of won a race or

[raymondharold]

My grandson races a GAS GAS 65 2024 we have we come value forks they have limited spring choices currently running the stiffest offered he weighs 120 lbs wo- gear he’s only 8 yrs old but really fast the air fork was harsh when we had to run 3.4-3.5 Bar to get some hold up. So the cone valve was what we went with the action is good but to get the hold up and balance we’re all the way in on the preload adjustment and 1 click from full stiff on the compression adjustment. We races Moto getting it safe for him is the most important thing he’s been racing since 5 yrs old and getting the Cobra 50 & 65 to work well was easier we used gold valves and could get proper spring rates. Do you have a suggestion for spring rates F&R even if we need to have some made by cannon race craft. I know he’s heavy for a 65 but he fits in pretty good ❤

[EricCogburn]

I’d be interested in hearing how you approach testing. Do you prefer to “bracket” settings by going really far in one direction with the clickers, then really far in the other direction and then see which end of the spectrum feels better? Or do you start in the middle and tweak one way or another? It would be cool to see a graphic of what pro tuners use to document feedback at the track—like a photo of whatever log you have in your notebook (or whatever you use). I feel like most consumers don’t have a formal testing process—they just randomly turn clickers and hope they stumble on something that works.

[motoxposse]

Question regarding moving forks up or down in the clamps. Let’s say you want better or faster steering in the slow technical stuff so you move the forks up in the clamps, should you reset your sag? Will resetting the sag off set the fork adjust up in the clamps?

[mickcain]

Do all dirt bike springs have a progressive spring rate?

[justinthomas]

Did any of you go to MMI? And do you recommend going?

[B.LanglaisCT]

I have a 22 fc 450 stock suspension not valved run the keefer testing settings and play with the clickers to try and get it right but it beats me up bad to get it to not bottom on hard landings and being the 450 I tend to OJ the shit out of most tables at the track and my wheels take the brunt of it just trying to see how if any way to make this better I ride moto am 5’10 170lbs any info would help

[weStayModest]

I just switched from being a lifelong 4t guy to a 2t and my front wheel always feels like it’s floating, I never feel like I’m connected to the ground anymore like I did on my previous bike. Is this synonymous with 2t bikes or is this a suspension issue. I checked my sag and it’s at 105mm in full gear, I set my clickers at the mid way point and I’ve been adjusting them but I never feel planted. I’m 185lbs fully geared I stand a lot and I’m 6’2.