How To Check Motorcycle Suspension Sag | MC Garage 

The mistake being made is that the total exposed slider is in no way indicative of the total travel. So all we know is that there is some amount of sag. We have no idea if the measured number is 99% of the total travel, or .0001% of total travel since we do not know where the suspension bottoms or tops out. So this was a nice video, but it's incomplete as it does not address the 1/3rd to 1/4th portion. All we know is there is X millimeters of sag.

@@PrivateUsername That is quite right. however total (or better to say max theoretical) front / rear suspension travel is normally given in the bike's specifications

You forgot a minus between L1 and the 1st bracket, just a heads up to anyone like me who is scratching their head at the high number they got by multiplying there :D

@@PrivateUsername on the front this is not a problem because u can measure the distance left but the rear, how would u approach that?

​@@PrivateUsername Yeah, with this in mind, I think this video's suggestion is actually wrong and possibly dangerously inaccurate. If you set up 25%-30% sag to the length of the shock's rod showing and especially some fictitious value gained from the backend, and not it's true available stroke, then you are setting it to something more than it should be. This is also assuming this percentage is also accurate. Front shocks don't bottom out where the rod showing is completely gone. They bottom out earlier. Let's test this: Shock Rod measurement (as in the video): L1=135mm L2=87mm L3= 97mm Sag = 135 - ((87+97)/2) Sag = 43mm Desired sag= 33 to 45mm So, the sag measured was at the "bottom" of the desired sag. I'd also add some more pre-load, but someone lazy might not, saying "it's still ok". Now, let's do it with the stroke of the front shock's cylinder (Ohlins it seems full stroke is 120mm): L1=120mm L2=72mm L3=82mm (taking off 15mm to match values 135-120) Sag = 120 - ((72+82)/2) Sag = 43mm (aha, the same...!!! So, that's ok.) However....Desired sag= 30mm to 40mm In other words, had the dude said, "it's within the desired sag, I'll leave it", he's actually over the desired sag and might end up bottoming out the cylinder in a pinch, which could be fatally dangerous. 43mm is 36% of 120mm stroke. That might still be "ok", but as we can see the suggested method here isn't completely correct, as you've pointed out and I think I've proved. I think the measurements in the rear would be even more false. We'd need to take some geometric calculation into the equation too, i.e. the angle from the attachment point of the swingarm to the point of connection of the shock to where the measurements were taken. Not easy. I also have learned that the sag on the rear should be less than the front. I've learned, 25-30 on the front and 20-25% on the rear. I don't know if that is true or not, but reading around, every other advice suggests at least a 5%-10% less sag in the rear to the front.

GT6SuzukaTimeTrials I dislike because he has very veiny arms

Way to jinx it 4 years ago. This is your fault

This aged well

RU-vid has gotten politically correct, I suppose, and doesn't show the thumbs down or dislikes that are entered anymore. A definite snowflake society move.

Caught that too.

Yep that statement doesn't make sense.... if you have no preload and too much sag you have no idea if the spring is too stiff or too soft. May be he meant to say that if you have no preload and not enough sag then the spring is too stiff, or if you have maximum preload and still too much sag then the spring is too soft? But even that isn't necessarily true because the spring may be the correct stiffness for the rider's weight but may be under too much installed preload. I found out from another youtuber that Ohlins sell different spring clips so the installed spring length (preload) can be adjusted beyond the adjustable range.

You can be heavy and not fat by being taller and/or muscular.

Ernesto Castellanos you can be heavy If you build a lot of muscle, and that's a healthier lifestyle than you probably.

Great info Ari, I've lowered three bikes for my wife over the years. It's difficult to do and maintain handling, safe ground clearance and reasonable travel. Would love to see your input on this topic.

lol shut up simon youve clearly never worked out a day in your life. "if you cant run a 10k, youre not healthy" WELP BAD NEWS EVERYBODY HEALTHY DIETS AND A REGULAR WORKOUT ROUTINE DONT MAKE YOU HEALTHY... MEMES DO?

Lmao damn 🥲🤣

Drax said that

LIKE A STATUE HE IS VERY GOOD !

where? i cant see him!

@@Mad8vCycles He is now in Revzilla's channel

@@dainesetube still cant see him... must be really sitting still

Thanks Ari

I recall hearing the same thing in his videos. He isn't always the clearest. It's a bit confusing definitely

to inspire you to do better and be better future my friend no country stay third world forever and no one stay poor forever

@@GPOLICE no you :(

150cc 13BHP here XD

@@14moldyhamsandwich in the 1st and 2nd worlds, maybe?

@@TakumisBizarreRacingAdventure 3rd world is not a rank. It's a fraction.

+Ari Henning Great tip, thanks! I have a '94 Yamaha Seca II so it's pretty basic. :) Mine came in great shape from its previous owner, so that helps a lot. I think you guys ought to host a riders' event! It'd be a good excuse to visit CA again. Or maybe you already do, in which case carry on. :D

Mountain bikers do this too but are not necessary as most forks come with a rubber o-ring to measure sag and most forks from RockShox have sag measurements written on the stantion tube. Remember to put the zip tie on backward so you can take it off without cutting it and don't leave it on because if you go through all your travel you will force the hard plastic dip tie into the seals. Or maybe motorcycle forks are different so that won't happen...

You should have also PAID attention in English class! 😉👍

akshay badami: ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-pNEmOqY02EU.html

0:35

between 1/4 and 1/3 of full extended length. 30-40 milimeters is quite usual 30mm would be stiffer: more sporty/track 40mm is softer: more comfy and pothole/bad roads friendly im pretty sure thats accurate but feel free to correct me otherwise

Are you saying your sack hasnt dropped?

@@ISwearDownOnMeNansGrave 🤣🤣🤣

You want a compromise between the two. Adjust to around 70% of the target sag you should have for just yourself. This is generally how a bike with passanger pegs is set up from the factory, for a weight of around 100kg. It's a compromise between a single rider and with a passanger. To get optimal sag for both single and double riders you would basically need two sets of springs and shock valving to swap out for each.

40(35-45)mm is good for street on a bike with 120mm suspension travel.

+hmushmann2 In automotive terms it's called droop.

It doesn't matter where or what you ride. Adjust not only your suspension, but the angle of you clutch, front brake, shifter & rear brake lever. MC's are not cars and are infinitely adjustable.

In essence, too little sag (too much preload), both front and rear, will lead to a stiff and harsh ride. The bike won't go over changes in the surface as well as it should. You may feel disjointed with the bike, as if you can't really feel what the tyres are doing under you. Not confidence inspiring and comfortable as it should. On the other hand, too much sag (not enough preload), both front and rear, will contribute to a soft ride. Not necessarily comfortable though. You may experience a lot more bike/suspension movement than you need to. The bike will feel "wolly" and will lack precision and accuracy. You'll feel a lot of weight transfer when transitioning from brake to throttle or vice versa. That's something you don't want to feel as your attention should be what's ahead of you when you ride. That's about it in a nutshell, hope it helps. Note, this doesn't take compression or rebound into affect

Simeon gave a detailed reply but I have a feeling its a bit off, because even in the video they make a specific point to say that changing sag doesn't affect spring rate. It changes the starting positions for the most part. Adjusting sag simply makes sure your bike, with you on it, is sitting in the correct position the bike engineers expected it to be sitting in as your ride it. With sag set correctly, if you hit a bump, you have the expected amount of inwards travel in your suspension to soak it up. But most importantly IMO, with sag set correctly, your bike has the proper geometry (mostly steering) as you ride forward. I once had a bike with too much sag in the front, and not enough in the rear, and it was a really odd feeling until I noticed it, even simply riding forwards at 35mph.

If the back end is too low in relation to the front the front end will feel light and like it has too little grip, similar to how a front end that is too soft feels, the steering will also be very vague and unpredictable. If the front end is too low in relation to the back end the back end will feel vague and unpredictable and the fork will punish your wrists on every bump. Having the rear set too high with a soft fork could result in sudden loss of front wheel traction (and a lowside) with little warning, and having the front sent too high with too soft suspension in the rear could result in the rear tire letting go with little warning (and a possible highside).

I'd also say, it is more rare to have too little sag. Though, if you do, that is more dangerous than too much sag (in the rear). In the front, too much sag is very dangerous, because then the forks could bottom out. Too little sag in the front is also very rare, and yet should also be completely avoided.

littlebr4d that's what he said. he said if that's the case your sings are too stiff. so same thing as what you said.

Yes, you're correct and he appears to have misspoken in this part.

"too stiff" which is what he says = softer, but I guess saying softer in this case would probably be a bit clearer in this case

Barry Roberts: You betcha! All suspension on motorcycles are already setup from the factory for you. But only if your 80kg +/- range. So if your heavier (or for doubling) you will benefit from a sag set-up. But once your pillion gets off the bike, well then your set-up is too firm for just yourself. So its all about compromise. 55kgs makes it heavier, but it also depends on the riding style & the type of motorcycle you ride. When doubling you ride slower & more carefully. So do you really need the tighter set-up? If you rode all the time with a pillion, & went gun-ho all the time, i'd strongly recommend a sag set up. So your 85kg, which puts you in that category of the manufacturers set-up straight out of the factory. But remember, both suspension front and back must work together as one. So don't tighten the rear & leave the front. Setting sag is about setting up your weight to the suspensions optimal working space. Cheers groover ;-)