www.DaveMossTuning.com There are several types of motorcycle shock preload adjusters. Dave reviews them, explains how they work, and how he counts the adjustments he makes. www.DaveMossTuning.com
This brings back memories of resetting my street triple back to stock parts after buying it in a lowered condition. The castle nuts were so stuck I had to take the whole shock off to loosen everything up, thank goodness that I did, as there were a lot of things put on the wrong way and the whole shock was a wrong bump away from catastrophic failure. Anyway, a useful trick is to rotate the spring itself instead of trying to rotate the castle nut. as mentioned, the weight of the bike needs to be off the suspension.
I think it’s important to note that preload doesn’t actually change the stiffness of the spring, per say. It does “make it stiffer” to add preload, ie compensating for additional weight or softer, less preload but that does not effect the spring rate of the shock or forks. It doesn’t effect the stiffness or softness. That’s a spring rate and valving thing. Preload simply is meant to keep the chassis geometry correct and the right amount of “pressure” on the wheels. For example if the preload is too light on a bump you might lose contact with the road. Too much preload and your tire might “push through” a bump in a corner. So it does change “stiffness” but. It really in the way you think. It’s different. The bikes weight. Your weight. Passenger. Luggage. ect. All push down. Preload is simply how much the shock is pushing back.
So if i were to compress the spring, would that help me from the rebound to feel slow? and also not sag so much? but too much compression would lead to the risk of having a "pogo bounce" and let my tire to lose traction?
Preload isnt the spring pushing back, but rather how compressed the spring is before you add the weight of a rider, passenger and or luggage. You want the spring, when you are riding, to be able to both extend into pot holes and compress over bumps.
Wow, pleasant surprise! I used to see you around Sport Bike Nights in Sacramento. You have adjusted my bikes when I was over there. I am in Hong Kong now and YT'ing bike suspension stuff and you were the first video that came up. Thanks!
Mr Moss, Thanks for these great lessons. You at re really a very top rate tech teacher. I'm learning so much from your vids. Im getting so much faster too. Have more confidence and feel on my CBR.
this video for me was a huge help Dave expertly done simple teaching demonstrating thank you. was totally confused as to what I was doing beforehand top marks
Inspired by you and your rear preload/sag videos. Thanks. Did a calculation for my '13 R1200GS LC. Sag is 22 mm more on its "One Helmet" setting compared to the "Two Helmet" setting. Well, 22 mm over a 1507 mm wheelbase changes the head tube angle 0.83 degrees, from 64 deg. to 64.8. The angle is the inverse tangent of the change in sag over the wheelbase = tan-1 (22/1507). Not a tiny amount.
@@catalystreactionsbw R1200GS or 1250 or GSA w ESA seems to really have 46mm of rear sag change from two helmet setting to one, an empty bike with 170#. 200mm total, two helmet setting can leave only 15mm rider sag but the head tube steepens up 1.75 deg (tangent of 1.75deg = 46/1507 wheelbase) and likes to turn. The OEM shock has 3 electronic settings, now call max fixed (for offroad), or auto or min. fixed (to dismount easier). You are fine man. Thanks. I'm 220# and use helmet plus luggage setting, sag around 62.
Hi Dave, first off your videos have got my blade to almost perfection. Thanks. Question I have is, is there a quick fix for adjustment when I take my daughter out on the back(6 maybe 7 stone increase), could I up preload or rebound, then just back it off when she's off? Any suggestions thankfully recieved. Cheers
I’ve been using a brass punch and plastic hammer to adjust preload on my bike. Even though the lock rings look accessible by spanner, even the smaller spanner I have doesn’t fit.
The preload tool should be used to PULL the adjusters round the thread rather than pushing them round. Which is an easy way to damage your knuckles when the tool slips.
Hello from Australia. I love your videos as you explain things so clearly and i learn so much from you. My bike only has the Step kind of pre load adjust on rear suspension and no adjustment on front (Suzuzki SV650 - 2018 model). It is still on the stock setting of 3. I’ve noticed when i go over large bumps that it throws me off my seat so is my suspension too soft for me (I am 81kg with out adding the weight of gear). I would also like to know what can i do to the front suspension to make it better handling? Should i get better springs and oil or just get whole new suspension? I don’t use it for racing so i just want to get it set up for a better ride on street and local mountains. I just want to now what I’ll need to do to it before i take it to a local Suspension place so i don’t get told any rubbish just to get me to spend more money than i need too. Thanks
Have you measured sag to determine if the suspension is too soft or too hard? I prefer to know: davemosstuning.com/?s=setting+sag. You also need to check static sag to see what you have as zero will through you out of the seat as well: davemosstuning.com/?s=static+sag. Got through these processes to assess where you are with sag then you can understand why you are leaving the seat.
Your expertise is just awesome and the way you add up small details are really neat thing for understanding. I do have a question though, how to figure out a correct preload settings for a solo rider avg guy (70kg)
Thank you! Set sag in the 30-40mm range. Set compression at 50% of the total range. Ride and see how much fork and shock travel you use and adjust accordingly. Ideal fork travel is 20-25mm above marked bottom out and shock is 2-4mm above the bottom out bumper.
Hi Mr Moss, love you videos. I currently have a Yamaha FJ 09 so By any chance do you have any videos adjusting the suspension on a FJ if not an FZ 09, it’s closest relative. Thank you very much sir!
I wish I had seen your videos before. I used to own a Street Triple with Nitron rear adjustment and I could never get my head around on how to use that damn thing lol.
Hi Dave, do you have a video showing how to remove the top yoke or bridge from CB 500 Honda F. As I need to replace mine as it was stolen and I retrieved it but now need to replace the top bridge. Many thanks Tom
Hi Tom. You will need to acquire a nut and washer to secure the upper yoke to the steering stem between the bar riders and the bolts each side to secure it to the fork. Tighten the center nut first, then tighten the side bolts last.
Good afternoon, please can you tell me if the rear shock absorbers of the 2001 vulcan 750 can be repaired and where can I buy the parts. I am writing to you from Puerto Rico. excellent youtube channel. Thank you
So, when people say Triumph rear springs are too stiff, from the factory. Does this mean the steel they use on the coil is too hard to have give,,,or is it the oil in the piston too small to allow travel of the piston shaft? Do you think air shocks are any good, or is oil better for stiffness or dampening?
1. The shock shaft inside the spring shows less than 50% travel used at all times with stock settings. 2. On a more technical level, there is no static sag at all so the rider is bumped out of the seat frequently on moderate roads. Changing stock settings to get 12-15mm static sag and assessing shock travel can eliminate much of that. 3. Damping for compression and rebound is set incorrectly amplifying bumps.
Have a first gen SV I was given a light use GSXR750 shock, which is a half inch shorter. Question is: should I use it? I could lower the front by the same amount.
I follow all your videos, your content is A1! Do you ever make it to the Circuit of Americas, in Austin, TX. I would love to have you look at my bike on track day!
I have been to a Ride Smart track event before but I have never been to COTA. If Ride Smart would allow me to travel to help riders (ie: they do not have a suspension technition helping riders at the event), I would travel to COTA .
Hi Dave, I was wondering. If I want to change my preload setup, and I want to measure the dynamic sag, do I have to worry about the compression settings? Because how I see it, if the rider sits on the bike, the compression rebound will be active. Or I'm I wrong?
If possible, always measure with hot oil. You can use existing settings in place for hydraulics or you can remove all compression damping (leave rebound as is). Do comparative measuring to see with your bike, your shock set up and oil age if there is any profound difference between settings.
Hi Dave! I need your help. I have a Ducati Multistrada 950 with REAR manual adjusters for pre-load, compression & re-bound. I ride luggage & I already max out my rear pre-load to its hardest setting but it still has a rider sag of 55 mm. What can I do to adjust it to bring it to 35 mm?
Nice adjustable C spanner wrench Dave! Where can I get one? I bought a C spanner wrench but it's too wide and non adjustable. Cheap aluminium one from EBay. Anyway I have owned a 2000 zx6r and sold it, now I own a 2006 gsxr 750. I lowered it by sliding the fork tubes up and a 3 position aluminium rear dog bone. Never really adjusted the damping until a week ago watching your gsxr sag video. I'm about 240 and have never raced only to work and back. My question is if I just change oil and antifreeze, how long will a stock bike last? This gsxr has 20,000 miles on it and has never seen red line.And what maintenance should I do myself or pay to have done? I might try a clutch and chain but not valve adjustments. Thanks for any help!!
You can do standard maintenance of air filter, spark plugs, oil and filter, coolant. A professional should do regular throttle body sync's with correct valve adjustment inspections/changes, Total life expectancy would be 70-80,000 miles.
Thanks for advice Dave! I hope you are staying safe from this dumb virus!? I am lucky to still be working through this rough time. Anyway, I haven't had many good weather days because I live in Xenia,Ohio. Do you know Brock from Brocks racing? He lives around Beavercreek,Ohio.If you're ever in town you gotta see some straight line drag racing at Kil-Kare race way in Xenia,Ohio.
Can I change only one side shock spring to get softer suspension while leaving the other unchanged. I know some forks have one side spring, other damping???
If you have two fork springs you can change one to a softer rate. if they are linear springs and for example you had 1.0 rate in the right leg, you would drop down to a .95 in the left leg. You would never drop from 1.0 to .90
My bike is currently too tall for me. I wondering if it would be a good idea to shorten the shock in order to lower the height of my bike. I have a 2011 speed triple. Thanks.
Lowering is a good idea for any bike if that allows you to stay safer when riding. The downside is less ground clearance and harder to pick up off the side/kick stand. Using adjustable (not pre-drilled) lowering links for the rear shock and then resetting fork position is the cheapest way to go. If you want to take travel away from the shock internally with a spacer, that can be done.
If you have not corrected the fork position to match the rear lowering amount, you will struggle on entry as the bike will be hard to turn and exit where the bike will tend to run wide.
Hi Dave Moss Tuning. If your still keeping an eye on this vids comments I have a question. Just picked up an 06 zx6r pretty sure it's stock suspension. I wiegh 250 pounds and ride to work with a heavy bag and gear so with that ride figure 300 to 320 pounds. If I ever ride with my wife we are close to 410 pounds with gear on and the rear is almost bottomed out. Any suggestions on what I can do with suspension replacement parts to handle the weight?
@@catalystreactionsbw thank you very much. I'll snag those up. Last time I ride was a decade ago on a 90 gsxr 1100 and I was 175 pounds so suspension replacement was not a worry lol. If that's the minimum size do you have a recommended size?
How does it shorten the spring and compress it more as you add preload? The weight on the spring remains the same so it just raises the seat height of the bike surely? Or am I missing something here? I could actually see the swingarm moving down as you added preload.
A shock spring can be progessive in ID between top and bottom (one wider than the other), progressive in shape (narrow at both ends and wider in the middle), then it can be progressive between each coil based on close to big gaps between each coil). Compressing with more preload the spring will in essence make the spring more resistant to travel. That will in turn force the shock apart and raise ride height (same with the forks).
@@catalystreactionsbw it will force the shock apart but the spring length will remain the same so it cannot be stiffer. When the shock cannot be forced apart any further and the spring preload actually compresses and shortens the length of the spring, then it will make the suspension stiffer and more resistant to movement. A progressive spring is still a spring with the weight of the bike on it. So surely adding preload, but not shortening the length of the spring will never make it stiffer. The fact that, as you say, adding preload will force the shock apart and raise the ride height of the bike leaving the spring at the same length, would also say the the spring cannot therefore be any stiffer. Preload can only really be for ride height adjustment for the adjustment of static and dynamic sag?
@@thedonkey60 Finally, someone appears to know how springs work. If there is any sag in the suspension (which will be true for any sanely setup motorcycle), then changing preload does nothing but change the sag. The force in the spring balances the sprung weight (which does not change), so preload does not change the force in the spring. And preload sure does not change spring stiffness, which is defined by the spring geometry (coil diameter, active wire lenght, etc.). It surely does not matter if we're using a linear or progressive spring. Of course, changing sag has some important effects; changing bike geometry, increasing/decreasing stroke to bottoming (so increasing/decreasing total force to bottom), etc.
In reading about the bike online there is no text that shows the rear shock is adjustable. That being said, consult the owners manual to see if there is the option to change it. If there is it will most likely be a ramp adjuster like a Honda CBR600
When the spring turns in conjunction with the adjusting ring it does so as a complete spring. The only stress is the friction between the spring and adjusting ring plus the holder at the base of the shock spring to lock it in place.
assassin stunter your weight, your spring usually oem you’re gonna find a spring that suits an average weight. On my s1000rr on the manual they say around 90kg (geared) is an average(for them) so the spring they’re not good if you’re 75kg even if you change all the settings.
There is no formula for the spring, but there is this rule of thumb: static sag should be 10-15mm with a cold shock, rider sag should be 20-25mm. Combined 30-40mm front and rear to start with a flat bike. If rider sag is good but there is no static sag, the spring is too soft. If static sag is bigger than rider sag, the spring is too hard.
@@danejurus69 Dave Williams, editor, replying here. It's the amount the shock and forks compress under the bikes own weight, without the rider on it yet. In other words, how much the bike "sags" under its own weight. Here are some video links about it. davemosstuning.com/2-clicks-out-shock-static-sag/ davemosstuning.com/fasterclass-setting-fork-static-sag/ davemosstuning.com/fasterclass-shock-static-sag/
I need to do this on my 14 Hayabusa. I'm a bigger guy and ride corners...or do the best I can (lol)...but holy crap it's a pain to get to the shock. Wish I could find someone in my area that was like this dude.
try a dirt bike shop if you have one close - they adjust preload all the time or find a local riding group. There will be someone in it that is handy with the shock preload tool. Once preload is set, don't forget about rebound and compression!
Mr Moss firts of all tank you very much for you wisdom and great comunication about tecnical stufs so important. I have a VFR Crosstourer DCT. I love this wonderfull machine but the suspension is very dificult. Could you help whith your big experience. Sorry about my bad english. Thanks for all. Gilberto
Hi Gilberto. How much do you weigh with normal clothes, how many kms on the odometer, what have you changed for weight savings on the bike, what tire brand, model and sizes are you using, are you solo or with a passenger?
My weigh with normal clothes is 95 kg, the bike as 43000 km. Im not changes any thing in the suspension, all the regulation in front and rear is from de the service manual, the tires in front is 110/70/19 rear is 150/70/17, daily a ride solo with a top case (givi +/- 5 kg). This wonderfull bike is a Honda VFR 1200 XA Dual clush transmisson 2012. I hope you understand my english. Thanks for your help Gilberto
I have a 2005 yzf r6 no matter what setting I try to set it at. I can never get the back to lift there’s no preload in it i put the ramp adjuster in the middle bottom and top I can’t firgure it out
Softer settings lets the suspension move more. If that is the case, the suspension compresses more and swat height might be less. This also depends on the material in the seat foam.
Soak then with WD40 or other penetrant for several days then try again. If they do not move, remove the shock, remove the spring and then try to move the rings.
"lengthen the spring to reduce tension.." You're actually reducing compression. :^) Tension is the force of pulling both ends outward (there is none here, the spring is always under compression). Compression is pushing the ends inward. A lot of people accidentally say this - just like when people say 'dampening' when talking about shocks haha.
idcspring.com/spring-lose-tension-when-compressed/ en.wikipedia.org/wiki/Compressive_strength In the first link, a spring company describes the compression strain as "tension". In the second link, along with everything else google finds regarding spring nomenclature, the extension strain on an extension spring is called "tension" while the compression strain on a compression spring has no name (I could give you the historical linguistics as to why, but I'm being too pedantic already). Hence the common substitution of "tension spring" for "extension spring" throughout engineering literature. However, IDC Spring company seems to be ahead of the lexical power curve and does refer to the compression strain as tension. They appear to use the term "tension" to label/name the strain on a spring regardless whether that strain is extensive/positive or compressive/negative. That said, Dave Moss might satisfy more engineers if he said, "I'm going to strain the spring" or "I'm going to add some strain to the spring / I'm going to remove some strain from the spring". Using the word "compression" for the spring in a motorcycle suspension context becomes problematic because the hydraulics have a "compression" component to them for which there is no suitable nomenclative substitute. But what do I know? I'm just an annoying linguist (who just coined the term "nomenclative").
@@okboomer1241 I appreciate your research and reply. As an engineer, I actually use those machines linked in the Wiki for product testing in RD! In the engineering world, strain is a measurement of elongation. It’s in the equation itself too - which is a result of tensile force or tension. Stress/strain graphs are an example. I didn’t know companies use the incorrect term and I wonder why. Maybe you’re right - not to confuse it with the damper’s compression adjuster. Or just sloppy nomenclature.
@@okboomer1241 I just noticed the first link and read the opening paragraph. They used compression and tension interchangeably haha. That’s really wrong haha.
@@TWIRKNOLOVE The era of "appeals to authority" is over. The spring company is an authority, you're an authority, Moss is an authority. This is getting as bad as epidemiology and climate "science." What's next? Gravity won't be a force anymore?
Surely adding or subtracting preload is changing your ride height, not making the spring longer or shorter (or stiffer /softer).It would only make the spring shorter as you increased preload if your swing-arm didn't move?
You just answered your own question, it does make spring harder and softer because it compresses, it also can increase ride height or add more resistance in height
If the pre load is increased as the load increases the ride height stays the same. The bike is always at full height minus static sag and minus rider sag. If you don't have these you effectively have no suspension and a rock hard ride. If you go full pre load you may as well have a block of wood instead of a spring
What is the point of hydraulic preload over standard? I've noticed that you can buy the same shock with this extra option for a few hundred more. Is it some rich person's lazy way of adding preload or is there more to it?
Why not call it a rook nut, since it looks like the chess piece? Plus it's one syllable. Thanks for the vids, between your expertise and forum browsing I managed to set up the suspension on my k7 sv650s and oh my god thet difference is amazing. I don't get people who don't set up their motorcycles, and I don't get people who just whine about how their shit is doing instead of actually figuring out how the motorcycle and its components actually work. Do you need an apprentice? lol, I'd love to learn. Hoping to start racing, but I still have yet to hit track days.
Reading the owners manual for my Triumph Speed Triple R, it has this 'Warning' " The rear suspension unit spring pre-load is not rider adjustable. Any attempt to adjust the spring pre-load could result in a dangerous riding condition leading to loss of control and an accident" Why would they put that on an Ohlins suspension, that is obviously adjustable.
Dave Williams, editor, replying here. This video just concentrates on one aspect of motorcycle suspension, the various types of shock preload adjusters. We don't talk about forks or hydraulics in this video.
Measure sag for yourself and set sag to your needs. Measure sag again (3rd party required) and set sag for the rear first. Once correct, then measure fork sag and set preload. Observe fork and shock travel used on a test ride or in the fist 80kms/50 miles to see where you are.
Wonder if Dave ever had a CD175 with a big top box for Spam butties and a thermos flask with a nasty cheap plastic "dayglo" orange that faded to hearing aid beige in weeks , as a winter hack to get to work at the main dealers bike shop in the winter time ? Don't think he's a handlebar mitts type . looks the age and every bike shop had a Dave who would do a service on your pride and joy at his place ....on the side for cash ..not sure why give all that up for the good old U S of A ...by now be head of parts and have a brown coat (warehouse) for use of.
@@catalystreactionsbw The old school Belstaff happy days in the kitchen melting tins of "wax" for the annual reproofing ..after a few hard years a good Belstaff can "stand" all by itself like a suit of armour and knocked backed from many a boozer..not like the modern over priced tat sell to hip dudes today ! If know any retro hip "ton" up uber kool with a "K" biker types show them You Tube RODE SAFELY 1955 FILM BY VICTOR HORSEMAN PART 1....a time when tyres with a "Y" was round and black Dunlop or Avon and Nobby Clark(e)'s still be found .. a good watch with a kipper breakfast.
Too bad in some motorcycle shops in the US the sales men are just plain incompetent or unknowledgeable and not caring at all about riders safety and comfort.
That's all we have in our industry for tools. Can you design and produce something better to help everyone that needs to use a tool like this? If not, that's a lot of disgust to carry around every day until the situation is resolved.
But you haven't answered the question we all need to know: Why would we adjust pre-load? What are we trying to achieve? On a road bike how much 'movement' are we looking for a safe but comfortable ride? It's a bit pathetic if you don't know how to use a 'C' spanner.
There are many other videos on why to adjust preload, how it is adjusted and what the end results are. Those are under the 2 Clicks Out playlist. This example show what tools you need and how to move them. 80% of suspension travel is comfortable and safe based on assessment of fork and shock travel. Now you know that, you can adjust preload to your precise needs.
Ben Zo you have to get it close, then later go back and make finer adjustments that the thread allows for. Guys with that much knowledge just can’t get it all out, it’s hard to translate a lifetime of learning to a few words.
Why did you say you are adjusting the length of the spring with pre load ? You aren’t ! You are extending the shock within the spring to gain ride height ! You aren’t making it stiffer by adding ore load ride will be softer , you make bike rider higher in stroke and therefore in the SOFTER part of the stroke . The further down you adjust ride height you are in the stiffer part of linkage and shock valving .
Dave Williams, editor, replying here. Nice catch! Language is a funny thing. One of my favorites is "incentivize" to make the noun "incentive" into a verb. But "ive" is a suffix used to turn verbs into nouns. To turn the noun "incentive" into a verb you drop the suffix. The verb is "incent". But language has changed so much in the last 60 years that auto spell check does not even recognize the word "incent".
