7:44 It's utterly realistic; it's called thread pitch. I promise and guarantee you that if you rotate that nut 1 turn, it will have compressed the spring by the thread pitch (or the nut has failed). ..I was a little surprised he wasn't rattling off the pitch of those threads and counting turns. It's not black magic.
He's not wrong. Doing thread math would only work when the shock is totally extended to its mechanical limit on the bench. As soon as you install it on the bike, it's under static load, and the number of turns of the adjustment are not a fixed ratio.
@@ryanferris9941 Nah. Not talking about installed ride height here. At 7:03, just before the question was asked, you can see we're measuring the location of the nut -- the shock is already fully extended -- looking to go from 145mm to 138mm. That shock is 1mm thread pitch; if he worked in 1/4 turn increments each time, it would be easier to count it off, and it would be 7 full rotations (28 1/4 turns) to arrive at the 138mm measurement he's looking for. The through-drilled holes that he often skips over actually mark 1/4s to make exactly this process easier.
@@privateparty4900 No, but that's the point. In 99.9% of the other times that you encounter the shock it will be under some kind of load. To set a rule of thumb that it will vary based on spring strength will be completely correct for 99.9% of the times you're going to measure it isn't wrong. And if you just turn and measure for the .1% of scenarios where the shock is sitting on a bench, you'll come out okay, too. Also probably faster to just crank and measure spring length than to try and measure and maths thread pitch for that single exception, too. Introducing this nit-pick that in this rare instance the thread pitch will dictate spring compression muddies the water for measuring it in day-to-day situations. Stop it. Especially considering the fact that this baseline preload spring length dimension will never come up again until the next time you take the shock apart.
@@ryanferris9941 He's got the shock sitting on a table. The question is "Can you just count the turns?" ...the answer was provably yes. Spring rate didn't even enter into the equation. As far as doing it on the ground and accounting for geometry, I could teach a child to estimate it within an order of magnitude.
With the right tools, it looks too easy!! Awesome! Question: shouldn't the new pre-load adjuster have some kind of lock ring so it does not undo with vibration or that's a special self locking ring? Just because I didn't seen any lock thread being used.
Ohlins uses unique lock rings to hold the preload adjuster in place. It has a pin and the upper ring has a locating casting for the pin. Google any Ohlins shock and you will see the pin and rings in place.
Hi Dave! I want to eliminate my remote adjuster as well, where can i find that collar adjuster and thrust bearing washer and all that? Could not find on ohlins site… thanks!!
Dave, some years ago an Öhlins shock hydraulic preload adjuster gave me problems. Over time, it would slowly lose preload and require additional turns of the adjuster knob. No fluid leakage was apparent anywhere. It was all a bit mysterious! My guess is the fluid leaked internally, past piston seals. Maybe it collected above the adjuster piston? Or it went to that place in the universe where all those lost socks go.
Hi Ricardo. I didn't know the sock fairy was an oil junkie too - wait, maybe that's why she needs the socks! There is an oil fill port on the reservoir so you would see dirt/dust residue there. If it was leaking past the o-ring, there would be a lot of dirt/dust on the top of the spring at the base of the hydraulic adjuster. It cannot disappear as it is a separate entity, unless the oil loss was so small when the shock was very hot, the oil atomized in the air stream as you rode. Interesting quandary to think through :)
ST1300 owners know about the disappearing oil in hydraulic preload adjusters. I don't think that it takes much over several years to cause the preload to decrease. I purchased an ST1300 last fall and the adjuster could be turned a long way without affecting preload. I followed several directions to flush out the remaining fluid and replaced it with the heaviest fork oil that I could find hoping it would disappear more slowly. Winding the preload on isn't fast enough for the higher viscosity to slow it down.
Shouldn't there be steel washers lightly lubed on each end of the spring, between the spring and ally threaded adjuster and the C shaped spring retainer?
On most shocks there is nothing these days. Yes, a steel washer that is lightly greased would be fantastic. A thrust washer would be even better (roller bearings) and make preload adjustments so much easier.
Hey Dave! Have you ever mounted a axial needle bearing in between the lock ring and spring? (You may need to make a sleeve to control it (lathe)) When you ride and the spring compress it turns a bit and when you set preload it's so mouth easier. /M Love your work man!
Absolutely! Penske used to offer thrust bearings with one plate containing the needle roller bearings and a plain plate above and below it. It certainly made my life a lot easier!
Sorry, the bystander is correct. While the strength of the spring makes it more difficult to turn the preload collar, there is an absolutely fixed correlation between turns/threads and the loaded length of the spring.
He's not wrong, tho. Only on the bench under no load at the mechanical limit is there a direct ratio. This is an exception. Every other time you measure spring length it's going to be installed under static load and floating. There will not be a direct ratio between threads and spring length.
Ohlins shock sat on shelf for 6 years and "...all the oil's gone out of the pre-load line so it's useless". Okay, six years is a while - but I'd still be a bit pissed off if it were may shock and I'd paid top money for it. And what's more, I'm wondering if the same thing couldn't happen even if it had been installed back in 2011. Anyway - thanks for uploading this, it was really informative.
We have no idea how the shock was stored etc and if it was empty 6 years ago to start with, so I have to be honest. Yes, frustrating for sure BUT, no serious problems and an easy and quite cheap fix.
I have the same shock on the R6 2004. Can i unscrew the nuts on top of the remote adjuster fully to the top and then use only the remote adjuster to set preload? Thanks
Brilliant dave love your videos really help. Question i have bought a ohlins su 503 for my gsxr 1000 k5 and its spring rate is 90n. I have been told thats the right spring for me at 165lbs bodyweight and about 176 in gear.Is this the right spring ? Spring is on and backed of preload measures 145mm . Dont know what unloaded spring length is ?. Do i bother to attempt to release spring and set at 12mm comp? Or assume its fitted correctly at ohlins. HERES A PICTURE . MY MAIN USE IS BUMPY BRITISH ROADS . WILL THIS SHOCK BE ABLE TO BE PLUSH ENOUGH FOR ME FOR COMFORT OR DO I NEED A WEAKER SPRING ? THANKS DAVE Brand new shock
160mm in the box, 145mm on the shock = 15mm preload. All good there. Set compression in the middle of the range and get rebound correct when the shock oil is hot. Normally OEM setting for rebound is slightly fast - a good starting point for UK roads. Make sure you assess travel used on the shock shaft!
so how much travel do those remote preload adjuster give you 25mm,50mm? also, can you use those top rings to move the hydralic preload body down the shock body, therefore, giving it more preload or not?
Generally a remote adjuster gives you 10-12mm of additional preload. That is why positioning the adjuster via the lock rings takes a while until you get the initial installed preload correct making the spring 10-15mm shorter than it was off the shock.
Dave I love your videos and I am certainly no expert but surely the weight of the spring has zero effect on how many turns of the collar it takes to compress it. The weight will make it easier/harder to compress but the distance the collar will travel is set by the pitch of the tread its being wound over.
If you have a linear rate spring, it will compress evenly to the rate/weight will not change. Setting the installed preload on the spring with a manual adjuster at zero can be measured by thread pitch and yes, that can be measured and calculated.
That's only true on the bench. As soon as the shock is installed--where you're going to be measuring it the most, it's floating between its travel limits under load, and the number of turns do not change spring length by a fixed ratio.
Came across this whilst trolling for a definitive answer. The preload adjuster on my Ohlins started dribbling fluid down the shock body onto my header when I attempted to add preload. Undoubtedly the seal(s) are fetzered. I continued on with my ride. Question: Aside from the obvious 'oil on the tire is dangerous etc' - Am I damaging anything by riding with empty adjuster?
That’s quite the mistake. Saying the preload adjuster travel is dependent on spring strength. Doesn’t matter a damn how strong the spring is. You want 135mm of preload the adjuster travels exactly same for a weak or strong spring. The only variable is the amount of preload, not compression rate.
Yes you are 100% right. In this video the preload adjuster had air in it so the preload setting was bleeding off, hence putting it to zero and calculating revised installed preload. A quick compromise when there was no immediate fix available.
I ask the rider to be very consistent in what they do when riding via skills and reference points at 70-80% where they can show excellent control. Changes then become very evident to the rider when things are better or worse.
Hmmm that's wrong my man, be it a weak spring or strong spring the rate of adjustment is dependent on the tpi of the thread not the spring strength.... Otherwise great vids🤔🏍️👍
Agreed - that is a level up in thinking where you assess TPI and effect for precision adjustment track in regards to rate change. Very few of us go to that level of detail so I appreciate the way your mind works and the detail you seek.
Not wrong as one turn of the preload adjuster may or may not change the length of the spring an amount equal to the thread pitch, it is absolutely tied to the rate of the spring. Why is this? Because we are dealing with two springs not one. The top out spring must become fully compressed before the main spring length will change an amount equal to thread pitch. Patience is indeed required.
Nice Jig , but how can a Professional Tuner say that turning a threaded sleeve will not have an exact effect on Spring height . He said a soft spring compresses faster total BS.. Unless that little Rubber bump stop is a factor .. The Problem with Suspension is that you have to work with it every day .. to stay familiar with all the little nuances especially of multiple brands and models .. Funny how suspension has 17 clicks or 22 clicks for rebound and dampening yet .. You probably won't every vary more than 3-4 clicks from your favorite position ..
The rubber bump stop is a huge factor especially if it imprints on the base of the shock body. While it does a great job of ensuring no metal to metal contact it will also degrade if abused.
Dave, this was fascinating and informative. Thanks for sharing your knowledge in a manner anyone can follow and understand.
I work at the same pace as you do, on things that I know about. Wham, bam!
OMG! Dave Moss with hair!
7:44 It's utterly realistic; it's called thread pitch. I promise and guarantee you that if you rotate that nut 1 turn, it will have compressed the spring by the thread pitch (or the nut has failed). ..I was a little surprised he wasn't rattling off the pitch of those threads and counting turns. It's not black magic.
He's not wrong. Doing thread math would only work when the shock is totally extended to its mechanical limit on the bench. As soon as you install it on the bike, it's under static load, and the number of turns of the adjustment are not a fixed ratio.
@@ryanferris9941 Nah. Not talking about installed ride height here. At 7:03, just before the question was asked, you can see we're measuring the location of the nut -- the shock is already fully extended -- looking to go from 145mm to 138mm. That shock is 1mm thread pitch; if he worked in 1/4 turn increments each time, it would be easier to count it off, and it would be 7 full rotations (28 1/4 turns) to arrive at the 138mm measurement he's looking for. The through-drilled holes that he often skips over actually mark 1/4s to make exactly this process easier.
@@privateparty4900 No, but that's the point. In 99.9% of the other times that you encounter the shock it will be under some kind of load. To set a rule of thumb that it will vary based on spring strength will be completely correct for 99.9% of the times you're going to measure it isn't wrong. And if you just turn and measure for the .1% of scenarios where the shock is sitting on a bench, you'll come out okay, too. Also probably faster to just crank and measure spring length than to try and measure and maths thread pitch for that single exception, too. Introducing this nit-pick that in this rare instance the thread pitch will dictate spring compression muddies the water for measuring it in day-to-day situations. Stop it. Especially considering the fact that this baseline preload spring length dimension will never come up again until the next time you take the shock apart.
@@ryanferris9941 He's got the shock sitting on a table. The question is "Can you just count the turns?" ...the answer was provably yes. Spring rate didn't even enter into the equation. As far as doing it on the ground and accounting for geometry, I could teach a child to estimate it within an order of magnitude.
Yeah absolutely, he didn't stop to think about this obviously with no load and full extension the spring will move as much as the nut, common sense
Like these videos where you take shocks and forks apart!
With the right tools, it looks too easy!!
Awesome!
Question: shouldn't the new pre-load adjuster have some kind of lock ring so it does not undo with vibration or that's a special self locking ring?
Just because I didn't seen any lock thread being used.
Ohlins uses unique lock rings to hold the preload adjuster in place. It has a pin and the upper ring has a locating casting for the pin. Google any Ohlins shock and you will see the pin and rings in place.
Very very informative. Thank you.
Very welcome
Hi Dave! I want to eliminate my remote adjuster as well, where can i find that collar adjuster and thrust bearing washer and all that? Could not find on ohlins site… thanks!!
Race Tech sells universal adapter kits that can replace the Remote Unit.
Dave, some years ago an Öhlins shock hydraulic preload adjuster gave me problems. Over time, it would slowly lose preload and require additional turns of the adjuster knob. No fluid leakage was apparent anywhere. It was all a bit mysterious! My guess is the fluid leaked internally, past piston seals. Maybe it collected above the adjuster piston? Or it went to that place in the universe where all those lost socks go.
Hi Ricardo. I didn't know the sock fairy was an oil junkie too - wait, maybe that's why she needs the socks! There is an oil fill port on the reservoir so you would see dirt/dust residue there. If it was leaking past the o-ring, there would be a lot of dirt/dust on the top of the spring at the base of the hydraulic adjuster. It cannot disappear as it is a separate entity, unless the oil loss was so small when the shock was very hot, the oil atomized in the air stream as you rode. Interesting quandary to think through :)
ST1300 owners know about the disappearing oil in hydraulic preload adjusters. I don't think that it takes much over several years to cause the preload to decrease. I purchased an ST1300 last fall and the adjuster could be turned a long way without affecting preload. I followed several directions to flush out the remaining fluid and replaced it with the heaviest fork oil that I could find hoping it would disappear more slowly. Winding the preload on isn't fast enough for the higher viscosity to slow it down.
great video .. now i understand more the suspension in sport bikes .. cheers .
Shouldn't there be steel washers lightly lubed on each end of the spring, between the spring and ally threaded adjuster and the C shaped spring retainer?
On most shocks there is nothing these days. Yes, a steel washer that is lightly greased would be fantastic. A thrust washer would be even better (roller bearings) and make preload adjustments so much easier.
Hey Dave!
Have you ever mounted a axial needle bearing in between the lock ring and spring?
(You may need to make a sleeve to control it (lathe))
When you ride and the spring compress it turns a bit and when you set preload it's so mouth easier.
/M
Love your work man!
Absolutely! Penske used to offer thrust bearings with one plate containing the needle roller bearings and a plain plate above and below it. It certainly made my life a lot easier!
Sorry, the bystander is correct. While the strength of the spring makes it more difficult to turn the preload collar, there is an absolutely fixed correlation between turns/threads and the loaded length of the spring.
Don't need to be an engineer to get that right mate ^^
He's not wrong, tho. Only on the bench under no load at the mechanical limit is there a direct ratio. This is an exception. Every other time you measure spring length it's going to be installed under static load and floating. There will not be a direct ratio between threads and spring length.
What kind of oil should I use if I just want to dump/refill/ or top off an ohlins preload adjuster? Thanks!
2.5w oil
Ohlins shock sat on shelf for 6 years and "...all the oil's gone out of the pre-load line so it's useless". Okay, six years is a while - but I'd still be a bit pissed off if it were may shock and I'd paid top money for it. And what's more, I'm wondering if the same thing couldn't happen even if it had been installed back in 2011.
Anyway - thanks for uploading this, it was really informative.
We have no idea how the shock was stored etc and if it was empty 6 years ago to start with, so I have to be honest. Yes, frustrating for sure BUT, no serious problems and an easy and quite cheap fix.
I have the same shock on the R6 2004. Can i unscrew the nuts on top of the remote adjuster fully to the top and then use only the remote adjuster to set preload?
Thanks
Nice wrist action on the jack handle Dave. Kinda getting me going here ;)
I love that even the pros use a breaker bar and plyers to work a bottle jack!!! 😂
The tool you use is the one at hand.
OMG where can I buy that shock compressor? Please tell me!
We made it ourselves. Didn't take very long at all. There are many versions of this available, Race Tech's being the quickest to acquire.
You make it yourself
Brilliant dave love your videos really help.
Question i have bought a ohlins su 503 for my gsxr 1000 k5 and its spring rate is 90n.
I have been told thats the right spring for me at 165lbs bodyweight and about 176 in gear.Is this the right spring ?
Spring is on and backed of preload measures 145mm .
Dont know what unloaded spring length is ?.
Do i bother to attempt to release spring and set at 12mm comp? Or assume its fitted correctly at ohlins.
HERES A PICTURE .
MY MAIN USE IS BUMPY BRITISH ROADS .
WILL THIS SHOCK BE ABLE TO BE PLUSH ENOUGH FOR ME FOR COMFORT OR DO I NEED A WEAKER SPRING ?
THANKS DAVE
Brand new shock
160mm in the box, 145mm on the shock = 15mm preload. All good there. Set compression in the middle of the range and get rebound correct when the shock oil is hot. Normally OEM setting for rebound is slightly fast - a good starting point for UK roads. Make sure you assess travel used on the shock shaft!
so how much travel do those remote preload adjuster give you 25mm,50mm? also, can you use those top rings to move the hydralic preload body down the shock body, therefore, giving it more preload or not?
Generally a remote adjuster gives you 10-12mm of additional preload. That is why positioning the adjuster via the lock rings takes a while until you get the initial installed preload correct making the spring 10-15mm shorter than it was off the shock.
Dave I love your videos and I am certainly no expert but surely the weight of the spring has zero effect on how many turns of the collar it takes to compress it. The weight will make it easier/harder to compress but the distance the collar will travel is set by the pitch of the tread its being wound over.
If you have a linear rate spring, it will compress evenly to the rate/weight will not change. Setting the installed preload on the spring with a manual adjuster at zero can be measured by thread pitch and yes, that can be measured and calculated.
I definitely should have changed to that peg style spanner instead of the reg spanner tired of busting my knuckles
Erm... I think you’ll find that for example if it’s a 1mm pitch thread on the shock body then for every turn the sock will compress 1mm
Could sure use a bit of oil on them threads. Wow!!!!
That's only true on the bench. As soon as the shock is installed--where you're going to be measuring it the most, it's floating between its travel limits under load, and the number of turns do not change spring length by a fixed ratio.
lmao at 5:50 dude riding a razor scooter with his track suit on
On an unknown youtube channel that day: "Overtaking 1000cc bikes on my 1 man-power scooter"
Came across this whilst trolling for a definitive answer. The preload adjuster on my Ohlins started dribbling fluid down the shock body onto my header when I attempted to add preload. Undoubtedly the seal(s) are fetzered. I continued on with my ride. Question: Aside from the obvious 'oil on the tire is dangerous etc' - Am I damaging anything by riding with empty adjuster?
No damage.
Shock from an 2000 R1 at an AFM race, I wonder if that is for Roger who kicks my butt in Super Dino :-)
That video is from a long time ago and Roger regularly kicks butt lol....
That’s quite the mistake. Saying the preload adjuster travel is dependent on spring strength. Doesn’t matter a damn how strong the spring is. You want 135mm of preload the adjuster travels exactly same for a weak or strong spring. The only variable is the amount of preload, not compression rate.
Yes you are 100% right. In this video the preload adjuster had air in it so the preload setting was bleeding off, hence putting it to zero and calculating revised installed preload. A quick compromise when there was no immediate fix available.
Why not repair the remote adjuster ??? @Davemoss
In that moment during the race wekeend, that was not an option as there was no way to repair it, hence the adaptation to overcome the issue.
how to differentiate between rider output error and bike setting problem
I ask the rider to be very consistent in what they do when riding via skills and reference points at 70-80% where they can show excellent control. Changes then become very evident to the rider when things are better or worse.
Dave I need you sir to help align my motorcycle
Please email me, dave@davemosstuning.com
Hmmm that's wrong my man, be it a weak spring or strong spring the rate of adjustment is dependent on the tpi of the thread not the spring strength.... Otherwise great vids🤔🏍️👍
Lol
Agreed - that is a level up in thinking where you assess TPI and effect for precision adjustment track in regards to rate change. Very few of us go to that level of detail so I appreciate the way your mind works and the detail you seek.
You're right man....I'm a machinist and I picked up on that mistake right away ..one turn of the nut = the tpi ;) regardless of the spring strength.
philip davidson true
Not wrong as one turn of the preload adjuster may or may not change the length of the spring an amount equal to the thread pitch, it is absolutely tied to the rate of the spring. Why is this? Because we are dealing with two springs not one. The top out spring must become fully compressed before the main spring length will change an amount equal to thread pitch. Patience is indeed required.
Nice Jig , but how can a Professional Tuner say that turning a threaded sleeve will not have an exact effect on Spring height . He said a soft spring compresses faster total BS.. Unless that little Rubber bump stop is a factor ..
The Problem with Suspension is that you have to work with it every day .. to stay familiar with all the little nuances especially of multiple brands and models ..
Funny how suspension has 17 clicks or 22 clicks for rebound and dampening yet .. You probably won't every vary more than 3-4 clicks from your favorite position ..
The rubber bump stop is a huge factor especially if it imprints on the base of the shock body. While it does a great job of ensuring no metal to metal contact it will also degrade if abused.
I don’t give a rats how good Dave is. No way I’d pay for patronising arrogance.
🤡