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However I do have a setup question, I have always been of the opinion if you got your spring rate right, be it coil or air, that really you dont really need to have any compresion damping on.. Right or wrong?
How long is a peice of string?
To a certain extent I agree, yes, that's the correct way to go about it:
A good spring rate is waaaaaaaaaaay better then trying to prop the fork up with more compression damping, and 95% of the time on the RS forks I've owned, I've run compression at minimum to be fair.
But some people like to slow the compression a bit for whatever reason, which is fine. Others people get carried away and I disagree with trying to compensate for crap set up with more damping. But that's just me.
Get your spring rate spot on and everything else is secondary. 🙂
(And rebound is more important than compression, but can we not go into that right now please? 🙂 )
Ah well - having set my spring rate, oil levels and weights and damping correctly I have no need for the lockout so all my forks with poploc have had the lever removed if remote or ignored if fork top.
I have no issues with excessive dive nor with bob. I get full travel , good small bump sensitivity and a plush ride.
Ok folks, listen up. The revs are not at all complciated really.
There's two settings - normal, and 'locked', via the lever. Compression damping in normal mode is set by the blue knob on the lever, and how 'locked' it is when you flick the lever is set via the brass knob on the fork. Simple.
I have always been of the opinion if you got your spring rate right, be it coil or air, that really you dont really need to have any compresion damping on.. Right or wrong?
Wrong. Imagine riding along on a flat piece of road, and then you hit a rock. If you had no compression damping, the wheel would rise up and swallow the rock, and you'd carry on. But what if the rock is bigger than 140mm? You'd bottom the fork out with a hell of a slam, hitting the rock effectively with no suspension at all. Compression damping is there to slow the fork down, so that when you hit a big rock you still have some travel left to work.
Some forks have not much damping in the first part of the stroke, but it ramps up as you compress the fork.
PP, if you think damping is not important, empty the oil out of your forks and go ride something rocky. And film the results, I could do with a laugh. You ride your forks on minimum damping, that's fine, but it's still damped!
Setting spring rate is the easiest thing in most forks, especially ones with a single chamber like my Revs - 25% sag and off you go. So if your forks are badly set up it's not the spring rate that's the problem. Damping is the key.
Wrong. Imagine riding along on a flat piece of road, and then you hit a rock. If you had no compression damping, the wheel would rise up and swallow the rock, and you'd carry on. But what if the rock is bigger than 140mm? You'd bottom the fork out with a hell of a slam, hitting the rock effectively with no suspension at all. Compression damping is there to slow the fork down, so that when you hit a big rock you still have some travel left to work.Some forks have not much damping in the first part of the stroke, but it ramps up as you compress the fork.
PP, if you think damping is not important, empty the oil out of your forks and go ride something rocky. And film the results, I could do with a laugh. You ride your forks on minimum damping, that's fine, but it's still damped!
Point missed, matey. You need to read what I type!
Me -
[i]I've run compression at minimum to be fair. [/i]
By that I mean the damping is set to minimum. It's very easy to understand! NOT that I [i]don't have any damping[/i]
As long as there's oil in the forks, no matter what you do with the adjusters, you've got damping. Fact.
And your +140mm rock theory doesn't work either. Even if you did have no damping AT ALL, no oil in the leg, the tension of the spring will still perform a rudimentary compression daming effect. What you WON'T have is any REBOUND damping to slow the return of the spring, so it'll extend at maximum speed and feel very pogo-stick-like!
Which is why I wrote [i]"rebound is more important than compression"[/i]
Because it's more important to have control of rebound adjustment than compression
And this bit -
[i]PP, if you think damping is not important[/i]
Shows you really have tken some words I've typed, added some more random ones, shaken them about a bit, and then read them! Because nowhere did I say that! 🙂
Go back and read again my child, because you're coming up with more of this BS and mis-information I refered to earlier, mostly because you've not taken the time to read and understand..... 🙂
Setting spring rate is the easiest thing in most forks, especially ones with a single chamber like my Revs - 25% sag and off you go. So if your forks are badly set up it's not the spring rate that's the problem. Damping is the key.
*Cough* Revs have 2 chambers: +ve & -ve *cough*
And you're wrong. Spring rate is more important. Change to 50% sag or 5% sag and see if it's not.....
Spring rate is what you set FIRST with any series adjustments.
Then damping after that.
Why?
Because a different spring rate requires different damping settings to control it properly, for a given weight of rider.
Simples. 🙂
PP I hate handlebar clutter and never bother switching lockout/damping on/off. I like a little lockout though to stop bobbing and diving.
The blue dial on the lever only adjusts how far the cable is pulled when you puch that lever - therefore gives a % of lockout rather than full lockout IIRC.
all this thread demostrates to me is how little many folk understand how to set up suspension. PP is pretty good with this stuff - listen to him if you don't want to listen to me.
Cynic al - correct
Easy now PP. The story with the rock was aimed at Tinsy, hence the tinsy quote at the beginning of it. I was explaining why we have compression damping. And it is a valid point. If there was no damping and you hit a 145mm rock you might get away with it, but then when you hit another 30mm rock immediately afterwards you'd be in serious poo. Even more so if you are say riding through a trough on a downhill - you'd be over the bars before you can say 'Argh I should've listened to Molgrips and his clear and concise explanations!' 😉 You might get away with one rock if you had no oil in your forks because there is intrinsic frictino based damping in the fork seals and whatnot.
But please note the above (and most of the original post) is aimed at answering Tinsy's reasonable question about why we need compression damping. So we all need to read posts carefully, don't we? 🙂
I have fully read and understood your post PP, I don't get why you are dishing out aggro to me. I am merely after a cheerful Friday morning chat, I don't want to be slagged off... If I may be allowed to make my point a little more competently than I did last time, I believe that damping is equally important to spring rate, not secondary to it. As anyone who's lost damping on a ride should be able to testify.
TJ - some of us like to adjust damping on a ride for a variety of reasons. One is for road sections - I rode hard home with my bike mostly locked out (despite having been not keen on the idea in principle) last night and it made it more fun and entertaining I think - felt a lot more positive when doing the urban warrior thing. Also, as mentioned above, with the adjustable rate motion control thing on RS, you effectively have two modes available at the flick of a lever - one for normal riding and one with lots of compression damping for say tricky steep bits. Not essential, but nice. I like to examine all the possibilities that my equipment gives me, which is why I have gone for this setup.
Molgirps - Sorry if it came over the wrong way, it was menant to be slightly light hearted, hence the smileys. Apologies if I sound a bit blunt! 😳
molgrips - but you don't understand what the various things do - hence you seem to think that compression damping does something it does not.
If there was no damping and you hit a 145mm rock you might get away with it, but then when you hit another 30mm rock immediately afterwards you'd be in serious poo.
Is just complete rubbish. if you have no damping at all the fork will just bounce up and down - what you need in that instance is not much rebound damping to stop it packing down and minimal / zero compression damping to allow the fork to adsorb the bumps. All having a lot of compression damping will do is prevent the fork from absorbing the bumps. You might as well have a rigid fork or a 60 mm travel one.
Get your fork set up properly and you don't need the lockout unless you are a low cadence stand up on the pedal rider when it might be useful to prevent bob.
TJ, you clearly don't understand damping, and we know from experience that it's IMPOSSIBLE to get you to change your mind, so I'm gonna leave it, with one final thought: Why do you think suspension designers (car, bike, motorbike etc) give you the option to change and tune your damping, and why do so many expert riders/racers/technicians spend so long tuning it?
Actually no, don't answer that. Never mind.
Merlin ones here aswell, pushloc works fine but they blow through the travel pretty quick. Sag is Ok but too easy to get full travel, more air to stop blowing through travel = 10% sag ffs. Can I put heavier oil in?
Suppose I coudl bodge the cable so the are alway on *a bit * damped with blue dial.
Molgrips - I have been adjusting and setting up suspension on motorcycles as well as bicycles for decades including stripping and rebuilding dampers to my own spec. I have read widely round the subject. You are confusing rebound and compression damping. Of course tuning your damping is very important. its just you are confused about what adjustments do what - as are most folk.
Edit - motorcycles back in the 80s used compression damping lockouts activated from the brakes ( antidive) soon discarded as a useless idea as locking out your fork stops the suspension from working
Why do you think suspension designers (car, bike, motorbike etc) give you the option to change and tune your damping
And if you work up from the bottom of the range, why is the first damping adjustment that becaomes availble always [i]rebound[/i] damping? 🙂
And that certainly applies to motorbikes as well as MTBs......
TJ I know exactly the difference between rebound and compression damping, I'm not the retard you think I am 🙂
And you can bang on about motorbikes all you like, most of them are ridden on surfaces that are very consistent ie road.
I understand the requirements of MTB damping to a fair extent, so I'll continue to tune my bike the way I like it, and analyse the results and adjust where necessary.
In any case - you said 'I don't know why anyone would want to adjust compression damping on the fly', and I am telling you why I like this ability. Why on earth did you then start telling me how wrong I am?
Sag is Ok but too easy to get full travel, more air to stop blowing through travel = 10% sag ffs. Can I put heavier oil in?
You do not need heavier oil. Your compression damping is not important. It is all in your imagination. TJ knows best!
(In reality, does sound like you need a bit more compression - heavier oil can work but bodging the cable is a good idea. If you were feeling brave you could tap the cable stop hole on the fork or the lever and fit a barrel adjuster off a mech, that would be an DIY compression adjust knob)
Molgrips - I tell you you are wrong because the example you gave about compression damping and hitting large rocks is simply incorrect. What you described is the behaviour with too much rebound damping "pack down"
You were the first one to mention motorcycles.
Sag is Ok but too easy to get full travel, more air to stop blowing through travel = 10% sag ffs. Can I put heavier oil in?
What forks are these? Rockshox?
If so, I'd hazzard a guess that dropping the -ve air pressure to around 10psi lower then your +ve pressure will help. Propping it up with more compression damping will just result in an unresponsive fork, and changing the oil will also affect the rebound.
It's rather hard to do diagnosis like this in the internet, it's a lot easier to DO IT than talk about it.
Your compression damping is not important
Again, you're not paying attention, that's not what he said. 🙂
Propping it up with more compression damping will just result in an unresponsive fork
Not necessarily. You can up the compression damping reasonably without making the fork too unresponsive. Remember, this is an MTB not a limousine, and it's not really worth chasing the ultimate plush ride over small bumps. I am of the opinion that you can put up with small bumps, but what's really important is taking out big hits and controlling dive and bob. I would suggest that, if the lockout cable is affixed to the damper via a grub-screw like mine, to try loosening it off and taking in a bit of cable to give you more compression damping. You might like it 🙂
PP do me a favour, I was clearly taking the mickey with that post! I do read these things carefully, trust me.
TJ - *sigh*.. I am not talking about pack-down, you completely mis-understand my posts. I was talking about what happens when you HIT a series of big bumps, accompanied by a change in gradient too perhaps. Hitting things is where compression damping is important, as I am sure you understand. And I seem to remember you first mentioned motorcycles when citing your years of experience.
Why does everyone on this forum automatically assume everyone else is stupid? I'm a pretty skilled bike mechanic, and I'm also very intelligent, analytical and observant. So when presented with a fork I explore all its options to see how it can help the kind of riding I do, by fettling it and examining how it affects the feel during riding. I've experienced forks blowing through travel too quickly, along with pack-down, bouncing off stuff, too plush of a ride, not enough etc etc. So I do know a little bit about this. I'm sure there are people who know more, but from what you've posted on here TJ you don't appear to be one of them.
The two original questions that sparked this were a) do you need compression damping (asked by Tinsy) and b) why woudl you want to adjust it whilst riding (asked by TJ). I've tried to answer these.
I like to adjust compression damping sometimes whilst riding because the terrain can change dramatically in the kind of riding I do.
scruff - Member
Merlin ones here aswell, pushloc works fine but they blow through the travel pretty quick. Sag is Ok but too easy to get full travel, more air to stop blowing through travel = 10% sag ffs. Can I put heavier oil in?Suppose I coudl bodge the cable so the are alway on *a bit * damped with blue dial.
What sort of weight are you scruff? Not ridden my new Revs yet and ideally don't want to be blowing through the full travel!
*bangs head on wall*
Pack down is what happens when you hit a series of big bumps with too much rebound. If you are using too much travel then you have too low a spring rate. More compression damping will stop it travelling over bumps but you loose all small bump sensitivity.
if you are running out of travel on a series of big bumps then you need a mix of higher spring rate, decreased rebound and increased [b]high speed [/b]compression. ( which is very rarely adjustable)
Using the lockout and blow off valve to control the multiple hits is simply stopping the fork from working and absorbing the bumps.
Downhill forks do not have lockouts . They hit big multiple bumps often. They will run minimal compression damping so as to absorb the bumps.
Teh lockout is to prevent bob when honking uphill in a low cadence
Why does everyone on this forum automatically assume everyone else is stupid
I'm not. But I know from what I've read here and in other places that there's a lot of misinformation and BS written about suspension in the MTB world. I've seen some truly terrible comments in mags over the years for instance. And that's what I think you've been influenced by. 🙂
Now, if your personal preference is to have a fork set up in a certain way, then fine, fill yer boots! But trying to pass on something to someone else that isn't really correct isn't a good idea really. More misinformation, more confusion. 🙂
Suspension is very simple. Approach it logically and methodically with the right info to hand and it's the work of minutes to sort out. Get confused by BS from 1001 sources and you're screwed.
Not necessarily. You can up the compression damping reasonably without making the fork too unresponsive. Remember, this is an MTB not a limousine, and it's not really worth chasing the ultimate plush ride over small bumps. I am of the opinion that you can put up with small bumps, but what's really important is taking out big hits and controlling dive and bob.
See, that's easily the best bit you've come up with so far. Your preference is for a tauter (Sportier? 😉 ) feeling fork and you're willing to loose some sensitivity for that. Great! And that's not propping it up with compression damping as has been alluded to elsewhere in this thread.
But trying to tell someone it's the right way to set THEIR suspension up is wrong. Because they might not understand your thinking and assume you're trying to stop the dive on a too soft spring with compression damping. Which then confuses them because it then doesn't feel like they think it should. Hence more misinformation, even if you don't intend it 😀
I try and tell people the basic, correct way of doing stuff, and try and help them [i]understand[/i] what the adjustments do, so they can then go about it in a logical way, aware of what they are doing, not just randomy twiddling dials 'because someone says it does so-and-so' 😀
If you have the choice of low and high speed compression, then you are in a better position because you can tune separately for small trail bumps and big hits. However the revs do not offer this I think. But yes, you are right about needing more damping, and this is what I have been saying all thread.
Using the lockout and blow off valve to control the multiple hits is simply stopping the fork from working and absorbing the bumps.
That's not what I was saying at all. I am using the lockout/blowoff to provide very high compression damping when negotiating very steep step downs and whatnot, where fork dive can tip you over the bars. So it'd only be on for a few seconds.
More compression damping will stop it travelling over bumps but you loose all small bump sensitivity.
Only if you go overboard. A *bit* more compression damping will help with stability and blowing through travel, at the expense of a *bit* more plushness. But as I said, we're not speccing luxury cars here, these are MTBs and we have suspension to tame big hits. I think that stability is more important than perfect small bump plushness.
They will run minimal compression damping so as to absorb the bumps.
I am not a downhiller, but I don't think this is the case. DH courses tend to have lots of large bumps in, so I doubt the riders are interested in small bump compliance. Anyone who rides downhill care to clear this up?
And that's what I think you've been influenced by.
No mate, I do all my own experiments and reach my own conclusions!
I try and tell people the basic, correct way of doing stuff, and try and help them understand what the adjustments do, so they can then go about it in a logical way, aware of what they are doing, not just randomy twiddling dials 'because someone says it does so-and-so
If you think that's what I'm trying to do, then you are way off the mark!
I suggested Scruff try something based on what I'd do. I know where he rides, and what the terrain's like. He's welcome to try it out and make his own conclusions. That's why I said stuff like 'you might try' or 'if I were you I'd...' My original post was to try and explain the principles behind compression damping.
In scruff's case, he specifically said that his spring was set up correctly because he has the correct amount of sag. Hence the finger being pointed at compression damping. I don't understand why you think I'm being wrong when you do seem to understand the principles the same as I do.
Downhill forks do not have lockouts . They hit big multiple bumps often. They will run minimal compression damping so as to absorb the bumps.
That is a complete load of ballcocks.
[b]Cynic-al[/b]The blue dial on the lever only adjusts how far the cable is pulled when you puch that lever - therefore gives a % of lockout rather than full lockout IIRC.
Posted 1 hour ago # Report-Post#
[b]TandemJeremy - Member[/b]all this thread demostrates to me is how little many folk understand how to set up suspension. PP is pretty good with this stuff - listen to him if you don't want to listen to me.
Cynic al - correct
No, incorrect. It sets the amount of cable that is pulled in the OPEN position. Why are you posting about something you clearly do not understand?
Edit: I can't be arsed with this.
Read kapusta's post on mtbr i linked to earlier. If you don't use the MoCo properly I don't care but you are missing out on the best feature of these forks.
LOL. This thread is rather amusing.
Since 90% of the posters clearly don't know how their dampers work, or what the adjusters do, surely the mtb marketing guys are barking up the wrong tree with highly adjustable forks/shocks.
It's just a recipe for suspension that works terribly due to poor set up.
correct Glenh
On most motorcycles now ( ducatis excepted) the adjuster range is minimal so people cannot get a totally wrong set up no matter how they fiddle. This is precisely because people get so confused over setup
If you think that's what I'm trying to do, then you are way off the mark!
No, I was telling you what [b]I do[/b]. 🙂
That is a complete load of ballcocks.
No it's not. Downhill forks DO NOT have lockouts, and THEY DO hit big multiple bumps, so at worst it's only 1/3 ballcocks! 😛
Since 90% of the posters clearly don't know how their dampers work, or what the adjusters do
Go on then, crack on! What does it all do then? Who's right and wrong? I'm all ears.... 😀
surely the mtb marketing guys are barking up the wrong tree with highly adjustable forks/shocks.
It's just a recipe for suspension that works terribly due to poor set up.
I do tend to agree with your setiment there though. I challenge anyone to pick fault with my Vanilla Rs! Preload and rebound and that's yer lot! I love 'em! 🙂
I'm a pretty skilled bike mechanic, and I'm also very intelligent, analytical and observant.
You forgot to add 'modest' on your little list there.
TJ, road motorbike analogies are not very useful here due to the vast difference in usage parameters...
You forgot to add 'modest' on your little list there.
🙂
Sometimes you gotta spell it out to TJ...
It seems me, PP and maybe TJ understand how our dampers work.... TJ's problem seems to be understanding what I'm getting at in my answer to his question about why you'd want to change damping on the fly.
It seems me, PP and maybe TJ understand how our dampers work
We certainly understand what our preferences are and how to adjust what we have to achieve them. 😉
No it's not. Downhill forks DO NOT have lockouts, and THEY DO hit big multiple bumps, so at worst it's only 1/3 ballcocks!
😆 No I meant the second part of his assertion. But anyhow I think up until recently at least (2008 maybe) that you could buy Boxxers with the regular MoCo damper which could be locked out. Maybe you still can with the MoCo IS. I'm not sure about that though.
So that would make it 100% ballcocks
We certainly understand what our preferences are
Not the same thing...
A picture is worth a thousand words...hopefully that clears everything up once and for all.
[IMG] 
[/IMG]
EDIT: I know it's a 2011 Fox 32 with the fancy gold coating in the drawing but the principle is the same on a RS rev
As a layman i am more confused than when i started reading this thread....might just go rigid 8)
As a layman i am more confused than when i started reading this thread....might just go rigid
1 set sag to approx 25%
2 ride
2.1 too much dive? more LSC (blue dial)
2.2 big hits coming straight through (spiking)? reduce floodgate
2.3 kickback after bumps? more rebound
2.4 fork not recovering quickly enough? less rebound
3 goto 2
As a layman i am more confused than when i started reading this thread....might just go rigid
I just got back from the pub, and thought it would be useful to do a recap:
1. There are at least 2 different remotes, one that adjusts compression, one that doesn't. Probably anyone that brought their Revelations from the cheap Merlin deal has a normal lockout lever without compression adjustment.
2. Due to (1), mostly everything else can be ignored, unless you want to faff around with zip ties to adjust compression.
3. retro83 posted a [url= http://forums.mtbr.com/showpost.php?p=1498056&postcount=13 ]link[/url] to something by someone named kapusta, who explains motion control adjustment in easy to understand steps for normal people.
4. Ignore everything after retro83s link and you won't go far wrong... 😉
got mine sorted now.......lockout locksout........ 8)
Good tuning summary retro83.
Of course, as others have said, if you use a remote lever that only allows 2 positions for slow speed compression, then point 2.1 is superfluous.
Oh, one more - getting compression spikes but too much bob/dive or not enough 'lockout' (since floodgate is wound right off): change for a lighter oil and use more floodgate.
2.1 too much dive? more LSC (blue dial)
Probably anyone that brought their Revelations from the cheap Merlin deal has a normal lockout lever without compression adjustment.
Of course, as others have said, if you use a remote lever that only allows 2 positions for slow speed compression, then point 2.1 is superfluous.
So if one has the on/off lever, what adjustment would you use to make up for the lack of compression adjustment? Or just not worry about it?
So if one has the on/off lever, what adjustment would you use to make up for the lack of compression adjustment? Or just not worry about it?
You could hard wire the compression by tightening the wire at the blue pulley.
Or you could do something with zip ties (I wonder if you can make the bar lever adjustable with a zip tie loop or something?).
Or someone else will say that you can put more/less air in and change the rebound. Then someone else will say you shouldn't do that. Then someone will get called a facist.
If you reckon that adjustable compression will make loads of difference to you then you'll be wanting to buy the correct lever, or change the assembly for a fork mounted compression adjuster.
Not worry about it.
If your fork is set up properly you don't need more compression damping. All the lockout does is stop the fork from working.
Well, you can run it 'on/locked out' and wind the floodgate off a fair bit.
That way you get a bit more low speed compression damping to control bob/dive and an active fork over bigger hits.
However, that means that a) you don't have anything that works as a lockout, and b) you might be a bit low on compression damping generally, depending on your weight/how you ride etc. (which would show up as blowing through travel easily, although probably not bottoming on air revs/rebas since then have a very progressive spring towards the end of their travel).
ducking all the handbags for a second and answering any questions posed at myself-
Merlin pushloc revs, Im 15st. They do blow through the travel, they do need a bit more compression damping without resorting to fully on with floodgate as is the option with these forks. Tried 15psi less negative, its a bit better, might reduce it further until it stops moving on small stuff.
cruff:
ducking all the handbags for a second and answering any questions posed at myself-Merlin pushloc revs, Im 15st.
*dodges gucci manbag*
Cheers for that. Hopefully at a slightly portly 12stone i should be ok then.