Setting Suspension Sag & Preload
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- čas přidán 9. 01. 2024
- In this video, Jeff walks us through his way of setting suspension sag and making preload adjustments on his KTM and similar motorcycles.
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Most sensible bit of suspension advice I’ve seen. I will never have to ask my wife to help me check my sag again!
😆
Jeff has the disposition of a crusty old gunsmith. As a gunsmith i can feel every annoying customer in his explanations. "You (ride/shoot) at novice level and your trying to tune your equipment like a pro. You ain't that good" The value i get from watching Jeff knowing that subject matter aside its the same game is comically validating.
He’s a clown. He knows more than alllllll the suspension companies. He can feel more than alllllll other riders. He knows more than allllll GNCC pros mechanics who are “late to the party”. This also comin from the guy who somehow wears 30+ lbs of gear 😂? Slavens don’t even do their own suspension anymore they have 2 local places who do all their work.
I feel like an idiot not using this method all these years! Never too old to learn though. Thanks Jeff!
You're welcome!
That's the best sag explanation I've heard!
It just makes sense.
Thank you.
Never thought of adjusting sag this way makes a lot of sense and a lot simpler thank you 👍
Glad to help
Thanks for this information Jeff, I’m a relatively new rider and this is very valuable.
Very welcome!
Another informative and great video! Thanks Jeff
My pleasure
Jeff always on point. 👊
Thank you.
I just became a fan and will be looking at your site for future parts needs.
Thank you. We have the largest selection of high quality KTM/HQV/GG parts on the planet and my staff will give you excellent support.
Yes Jeff!! Finally talking some sense into these egghead know it alls!! I have been using your method for years. Too many guys get caught up in the sag numbers. I'm all about the correct spring rate for my weight (front and rear) and the recommended preload then ride and adjust clickers as needed. To be honest I rarely mess with my sag.
I like this approach. I defaulted to it when I had my bike tore down. Before the tear down I had experimented with the full range of preload and nothing worked it to a “correct” sag number. So when I did the service I used manufacturers recommended preload on the bench and stopped worrying about sag number.
Thanks Jeff!!! I am definitely going to do some trail side tweaks this season.
Go for it!
Great video, I race team suspension tuner told me to run between 6 - 8mm preload, and don't worry about all the other rubbish.... I did that, back end was a bit lively, so I backed it off to 6mm,....perfect 👌and the bike handles better too !!
I found this method on a GasGas forum 20 years ago and its been my go to since. Rock solid. Even if your riding a bike with the wrong spring. Just preload it 8MM and adjust as needed from there.
Thanks Jeff ! Great info as usual !
You are welcome!
Great video Jeff. Just got a spring from you guys, I'll try your method.
Thank you
Thanks Jeff for helping to demystify this process. You showed us that it is not that hard to do.
Very good tutorial video as per usual 👌
If I may offer a tip..for those reading the comments and struggle to get the right feel of the suspension due to underweight.
Choose a smaller rear tyre as the weight will distribute towards the back end.
Jeff is the man!
Thank you!
So true I do like Donuts🤣. Thanks for all the great info Jeff. Always great videos. With great info.👍
Thanks for watching!
You might be answering this in a future video, but when researching shock springs I see straight rate and progressive rate springs available. Hoping to learn the advantage and disadvantage differences, and if they are set up differently for sag, compression and rebound. Love these videos, Jeff!
Hello:
Thanks for your comment. Stay tuned for a future video on that subject.
Thanks. I did notice a big range of results depending on whether seated and up on the tank vs. more relaxed or standing. Was frustrating trying to get repeatable results. Especially solo, taking a video with my phone on a tripod, zoomed in on a tape measure. 😮💨
Thanks Jeff, really good like you say most riders can't feel the difference between 2-3 turns or mm either way . I like how you talk about being honest about your weight, I forgot about putting water in the backpack.You take a lot of BS out of your way of working. I remember one video where you were laughing about the what you called the Torque-a-holic. Thanks for making great videos we all appreciate.
Glad to help!
This was great, makes real world sense. Not crazy at all.
Thank you.
Thanks Jeff!
You're welcome!
I've had no trouble setting sag and getting it to feel pretty good, I would just ignore static sag. But this method is so much easier especially when different tire/mousse combinations can feel different enough to make you want to adjust the spring a turn or so.
Fantastic
Thank you! Cheers!
Most people can't get the numbers to line up because they chase static sag. There's no possible way that a spring that is 2 rates stiffer than a stock spring, with the same preload, will ever have the same static sag. The stock bike would have much more static sag than the other. So people start trying to dial it the static sag and then the race sag gets all out of whack. I agree with you. Setting the recommended preload on the correct spring for your weight should get you pretty damn close to the correct rider sag. Might not be exact, but good enough for 80% of riders.
I usually measure my sag from the floor to the bottom of my sack to see if I'm ready to ride that particular day. On a serious note, I think now I need to back off my spring adjuster big time. I remember turning that thing numerous revolutions to get the 105mm sag. It is a progressive rate so not sure if Jeff's method is for both types or just straight rate springs.
Hello:
My method applies to straight and progressive rates however I like your floor to sack measurement. I'm looking forward to your video but please wear clothes, ha!
Thanks Jeff, Finally a video about preload. I am amazed how few people including so called suspension tuners understand preload cause and effect. One question Jeff, what do you think is max.and min. my guess is 4-10.
Hello Jack:
If you get the adjustment outside a 5-10mm range, you have the wrong spring.
Thanks Jeff that's what I always thought. I'm at 6-7 now with your spring and National and my 300 is perfect and awesome. @@slaverace1
I got my springs from Slavens. I can vouch that if you don’t BS and weigh with your full gear, you will get the correct spring rate.
Thank you.
Im a newb and appreciate this information. I got the new 2024 ktm 300xcw thats apparently tool free. Im 6'3 and 215ish with no gear. Ive rode bike stock few rides and love it but as you described im not good enough to know the difference yet. Im hesitant on making any adjustments thinking i will need to raise handlebars. Am i correct that i should determine if i need risers before i start making adjustments to the bike? On your balance video you discussed front and back but this video only discuss rear. Thank you for these videos.
Hello:
I'm the same height/weight as you and I feel very cramped with the stock ergos. I raise my bars 15mm slavensracing.com/shop/enduro-engineering-handlebar-risers-for-ktm-husaberg/?attribute_part=EE23-1024, install a Seat Concepts Tall Comfort seat
slavensracing.com/shop/complete-comfort-seat-for-ktm-by-seat-concepts/ (not the XL) and back and 5 down/10 back lower pegs by Carapak, slavensracing.com/shop/stainless-steel-footpegs-by-carapaks/. You should also rotate the bar mounts 180 degrees to the more forward offset. All of these changes combined will make a big difference in comfort and control.
@slaverace1 what rear spring do you recommend on the 2024 xcw hard enduro? Trying to get sag to spec being your weight and height
Cool
Jeff,
this is the smartest, simplest method of setting sag I've ever seen. Now, for the dumb question. For a loaded up adventure bike, KTM 690/890 in my case, how should total weight be accounted for, since some of it is on the back end? I'm at around 30# extra. That's the weight of luggage itself, camping gear, clothes etc. Seems having most of the weight in the center over the pegs, and some hanging off the back of the bike makes a difference?
Hello:
Each spring size for KTMs covers 22 lbs. of rider/gear weight. At 30lbs. of extra gear, that will need accounted for by changing the spring rates.
I bought front and back springs (2 up for my weight) from Slavens about 4 years ago for my 450. Huge difference. Now I have springs in transit as I write for my 701. A question....should I drop the spring out from the bottom and put the new one in just by unbolting the linkage or do you recommend removing the whole shock? Thanks.
Hello:
You definitely need to remove the spring and you will also need a spring compressor.
Jeff - I found you from Cody at Wranglerstar a while back. I love your content and also the enduro footage is incredibly fun to watch. My question is specific to my bike. I'm 140# and with gear about 150. MY 03 RM 250 I'm just starting to ride with 25 original hours from the showroom floor. 5 hours now that it's in my hands moving forward. 100% OEM stock with no mods. That said with an inseam of 28" it's a very big bike and despite handling I've lowered the spring all the way down. I need to get a lowering link, how would that play into all of this? I'm sure I'm over thinking it. To me learning to ride track is hard to begin with, so it's difficult to even feel the change vs my lack of skill. Please let me know what your thoughts are if you can. Much appreciated. Keep on riding!
Hello Dave:
Just set the sag to the factory spec and ride it.
@@slaverace1 Thank you so much. I appreciate your insight and all the knowledge you put out there for the community. Be well!
We all like donuts, and you might not get there! Hahahaha!!!!!!!!!!
I bought a 2000ktm sx 250 and rebuilt the bike, it would buck like a donkey so I reduced the compression out back and set the preload to hand tight. It rides like a dream on trails without bucking but pushes on fire roads. If i pre load the spring is it going to start bucking again? I cant find much on my old ktm for settings
Jeff will shortening the suspension alter preload ? Thanks.
Hello:
If the shock is shortened (not a shorter linkage arm) you may end up with a little more preload (1-2mm) BUT don't overthink it. Install the correct spring from our chart, set the preload, install the shock, go ride and adjust as needed.
Question!
I have a 2017 KTM 300 that stock spring was 42-247. This spring was way too soft for my weight. New springs are 260 length. Does this length matter when looking at my manual that is for a short spring? My manual says 7mm of preload. However is 7mm of preload on a 247 different from 7mm on a 260? Part of me thinks the 260 would need more preload to match a shorter spring.
The 260mm springs will work on your shock. If you want to preload the spring 7mm, you are looking for a 253mm measurment.
Jeff what is your experience when going from a short rear tire to a tall rear tire (EX: at81 to mx33). I made this tire swap recently and found the rear of the bike high. I had to add some sag and raise the front of the bike in the triple clamps. Kinda got the balance feeling back to where it was but now the bike sits high and I find myself having to re calibrate my lean angle and balance in the corners. I think I really do like shorter tires due to ride height. Have you ever documented how tall different tires sit when mounted and aired up?
Hello:
The way I address this issue on my bikes is to install a tire that has a similar profile as the original AT81. I prefer to keep thing simple.
@@slaverace1How would I find a list of tires with the same profile as at81?
My suspension guy actually gave me similar advice but said to only set static sag and dont worry about rider sag. Any thoughts on rider sag?
Hello David:
No offense intended, but you seem to have missed the point of the video. I don't set rider or static sag.
Dumb question, after setting the preload and riding would there be different feedback so I’d know wether to adjust the spring preload versus the compression/rebound? …all assuming the correct spring is installed.
Hello Krinklehead:
As explained in the video, setting the preload primarily effects balance and has little effect on clicker settings. Dive in, make changes and sort it out.
I use my 500 EXC for both dirt riding and adventure riding with about 25 pounds of luggage. If I set sag according to the method in the video for most of my riding, how do I know how to adjust preload for the extra weight of camping gear?
Wayne:
In the video I explained that each spring rate covers 22lbs. of rider weight, so you need two springs, one for dirt riding and one for adventure riding.
👆He's right, ya know... This method literally takes the guess work out and even if you set based on sag parameters, you'll still have to go ride it to see how it feels. This gets you passed on the BS and possible hiccups and straight to the 'go ride it' part. It's a genius method nobody knows about. Now, knowing Jeff (which I don't, just been watching his vids forever), he only shared this gem of knowledge with the mortals because it stops the dummies from calling him with silly issues. Now STAY OFF MY LAWN! :-) ✌😆
On my 2024 xcw if i change the rear spring to get the good sag do i absolutely need to change the front spring too?
Yes, to keep your bike in balance you should always do fork springs AND shock spring. Never one or the other alone. You would be better off leaving the stock springs in over just doing a shock spring.
@@slaverace1 yes i saw your other vids, i already pass the order for the front spring. Thank for the response
Why not measure the sag traditionally after this (better method) to get a base number from that? That will be then available for micro-adjustments because when you stick something on a moment arm, it gets easier to measure small changes (I agree however that I and most riders can't tell the difference). Anyway - awesome as always - Slavens rocks - the only sticker on my toolbox.
Hello:
Thanks for your comment.
The whole pretense behind my method is to NOT use the flawed sag measurement method, so why do you want to go back to that method??? If you want to make a small change then loosen the preload adjuster lock ring and make a change. If having a "number" on file makes you happy, put the bike on a stand and measure the spring length and write down that number.
Regards,
JS
@@slaverace1 Indeed sensei - I just meant that 0.1mm on a spring is maybe 5mm at the end of the arm - so it's more like a fine scale.
KTM quote that rear suspension sag on the 890 Adventure R should be 80mm with a 85kg rider. I'm 90kg and the sag is 69mm (installed preload is as supplied; and preload is a adjusted to 0). The front is worse than the rear. I know it when I ride the bike, and the sag figures prove my point. So I've changed the front springs from OE 6.7N/mm to 6.0. It's much better, but still too hard, so I've ordered springs the next step softer, 5.6N/mm. I'm making big changes, and the bike's getting better. Manufacturers can be wrong, or we may be using our bikes in a different way to how they were designed.
Hello Red:
Sounds like you are trying to improve ride quality (better compliance) and are going about it all wrong. You're turning it into a wiggly wobbly mess (no offense intended). For your weight, you do need one size up in spring rate to hold up your weight and the bikes weight. The issue you are attempting to address should be corrected with the internal valving, NOT the spring rate.
@@slaverace1 Thanks for the reply - I wasn't expecting it.
I didn't go too deeply into the story, because it's a bit long for a YT posting, but I am looking for more suppleness, so have purchased TracTive suspension (cartridges and a shock). The new suspension came with the softer springs, but they still need to be softer in my opinion. When riding on gravel roads, often with washboard, the original suspension would not give, but would cause the front wheel to be struck sideways, rather than to absorb the bumps. The new TracTive suspension is much better (I can ride the same roads 20 to 30 km/h faster) but have found the best result with the compression damping set at 0. Which is why I would like to try springs another step softer.
Why has the KTM 890AR been given 240mm travel if I can only ever use 130mm of it? My old KTM 950 Adventure had much softer front springs 4.8N/mm v 6.7N/mm, but rode very nicely considering the development age of its suspension. I'm riding these gravel roads at 130-150km/h (80-93mph), so I would expect more of the travel to be utilised.
How is it that WP (OE equipment) AND TracTive have got the valving so wrong, if it is the valving that is at fault?
The old expression, there’s more than one way to skin a cat brings true here.
This is a ballpark practical way so long as your spring matches your riding weight.
I differ on your opinion about standing on the pegs.
As long as your standing balanced over pegs, your height has no affect.
Here’s why I prefer using the Motool sag tool.
It’s consistently accurate. Using the sag for small adjustments is much more accurate than measuring the spring compression method.
So if you want to use a specific number at a tight track, and another with long straights, you can reset with 100% accuracy.
I’m guessing that this video is targeted more towards off-road and the method described is hard to argue with.
Basically it’s like tire pressure. Air down till it feels right
Hello:
If your method works for you, that is fine with me. However, your sag method is very flawed for all the reasons mentioned in the video. There is no such thing as "100% accuracy" when setting sag. My method works very well for all types of bikes, MX, off-road, ADV or whatever.
I knew Jeff Bridges rode dirt bikes man
Can you describe the process of achieving and measuring 8mm of preload?
For Example: 24 PDS bikes come with a 225mm shock spring. You will want to install the spring and turn the preload adjuster until the spring has shortned 8mm. 225mm - 8mm = 217mm. Measure the length of the spring not on the bike, then turn the preload adjuster until the spring is 8mm shorter.
This is all great but…once you have it feeling good, why not record your numbers at that point so after maintenance etc you can get it back to where it was?
You could simply just measure your spring preload after you have it where you like it and put the spring back on with the same preload as before.
@@slaverace1 makes sense!
Who knew using a sag tool was so difficult! lol
Rear axle position will affect sag.
A lot of things effect sag and you are correct.
what about the forks? Is that next video?
Stay tuned, it's in the queue.
Thought I was doing it wrong for 50+ years , but maybe not ...
looks like your spring table has errors for 450 MX bikes. They have 42 spring by default. Not 45.
What year, make, and model are you looking for?
@@slaverace1 ktm / husky 19-22 sxf
I just looked at our rate chart and we show 18-22 450 SXF/XCF bikes coming stock with a 45 N/mm.
now you tell me :) this is not common knowledge and should be.. make perfect sense
Thank you.
Follow your butt
Is that Charles Manson? 🤣
Easy now.