Good Suspension Setup

[G]

I have done a search but didnt really find anything definative, or anything other than posts saying use the search function.

I feel the suspension on my standard SVs is very soft the front in particular.

I have looked in this link below and it suggests completely stiffening the front up by unscrewing all 5 lines. But says the rear is not adjustable when it clearly is as it has 7 settings unless I'm missing something.

http://www.performancebikes.co.uk/pdf/568/209392.pdf

Any information on how other people have set up theres would be appreciated.

Thanks in advance.

[rictus01]

There are loads of posts on suspension, and I'm not going through it all again.

In brief,

front forks, standard springs are rubbish, you need to change them (search on front springs), when doing it set rider sag (search on sag) then front damping (search on emulators).

Rear shock, is onlt adjustable for preload (as are the fronts) search on rear shock) and will need replacing to upgrade (but if your's is new then set it to the highst it'll go and change it once it's shot).

also checkout "dogbones" for the angle of the bike.

Cheers Mark.

[rigor]

I have done a search but didnt really find anything definative, or anything other than posts saying use the search function.

I feel the suspension on my standard SVs is very soft the front in particular.

I have looked in this link below and it suggests completely stiffening the front up by unscrewing all 5 lines. But says the rear is not adjustable when it clearly is as it has 7 settings unless I'm missing something.

http://www.performancebikes.co.uk/pdf/568/209392.pdf

Any information on how other people have set up theres would be appreciated.

Thanks in advance.

Ignore that PB setup sheet. The SV they used had Maxton springs, and it looks like different Dogbones (and I would guess a different rear shock if they claim it had no adjustment) The perils of putting a double page spread as two seperate pages of a PDF :rolleyes:

Anyway, if you're looking for a "This is the set up for the SV" you won't find it. Every rider is different, and wants different things. Search for Rider Sag, and set up your bike for your weight, then see how you feel.

Oh yeah, and listen to Rictus :D

P.S. To "stiffen" (Note the quotes, it's not actually stiffening your suspension) you'd want to screw the adjuster in, not out.

[Sid Squid]

The suspension will only be stiffer if you change the springs.
Preload changes only the suspension's position in it's available travel under any given load.

[ejohnh]

The suspension will only be stiffer if you change the springs.
Preload changes only the suspension's position in it's available travel under any given load.

Well roger me rigid!.. I increased preload on my back sus by two notches(now on four) and it is vastly improved. Feels much stiffer too. :D

[rob13]

I wound out the forks and found under braking the bike tends to try to sit up a lot more. Took a while to get used to.

[Sid Squid]

Well roger me rigid!.. I increased preload on my back sus by two notches(now on four) and it is vastly improved. Feels much stiffer too. :D
Well... It's not stiffer, it may well feel different but it's the same spring under the same load, (unless you coincidentally lost a bunch of weight when you reset the preload of course), in fact as the SV has a rising rate rear suspension linkage - that is; at full extension 'X' amount of suspension movement results in 'Y' amount of shock movement, however at full compression, the same 'X' amount of suspension movement could result in 1.5-2 x 'Y' shock movement - so, the higher your preload the lower you are in the rate of movement curve, thus upping the preload softens the suspension, (for any given point in the suspension's travel), by a weeny amount it's true - but it is true.

The ONLY way to stiffen the suspension, is change the springs for stiffer ones, (or ruin the handling with loads of compression damping - but it's not the same thing really and isn't an option with standard SV shocks and forks as they're not adjustable.

[toonyank]

Well... It's not stiffer, it may well feel different but it's the same spring under the same load

Not exactly true but I inderstand the point. These compression springs not constant force springs, the spring rate increases as it is compressed (preloaded)

[Sid Squid]

Not exactly true but I inderstand the point. These compression springs not constant force springs, the spring rate increases as it is compressed (preloaded)

Wrong.

Under any given load the spring compresses the same amount, changing the preload changes only your position in the suspension's travel.

It's a dynamic system, the spring is not reduced in length under load by preload changes.

[toonyank]

Wrong.

Under any given load the spring compresses the same amount, changing the preload changes only your position in the suspension's travel.

It's a dynamic system, the spring is not reduced in length under load by preload changes.

This goes against everything I've ever known about the definition of "preload" explained below:

http://www.uponone.com/howtos/4.pdf

[ejohnh]

Wrong.

Under any given load the spring compresses the same amount, changing the preload changes only your position in the suspension's travel.

It's a dynamic system, the spring is not reduced in length under load by preload changes.

The force needed to compress a spring increases as the spring is compressed. So it is stiffer when compressed relative to when it is uncompressed. If the preload adjustment compresses the spring by a fixed amount then surely the effective spring is stiffer than when uncompressed.

Or maybe it's all in my mind. Wouldn't be the first time I have been mistaken - that I can admit to.

[toonyank]

The force needed to compress a spring increases as the spring is compressed. So it is stiffer when compressed relative to when it is uncompressed. If the preload adjustment compresses the spring by a fixed amount then surely the effective spring is stiffer than when uncompressed.

Or maybe it's all in my mind. Wouldn't be the first time I have been mistaken - that I can admit to.

Edzakary :D

[northwind]

Um, no offence but that'a pretty horrible guide there... Lots of bike-specific assumptions, but more importantly it contradicts itself constantly- it tells you to use preload to set sag, but also that it's to be used for stiffness- then, when addressing too soft/too hard issues, addresses only damping and doesn't mention preload. It's not all bad but there's too much simplification, some actual out and out mistakes, and plenty of room for confusion. Lots of better guides out there. Ohlins, WP, Traxxion among others will agree with Sid Squid here, but you're absolutely right, you can find people stating it either way quite easily.

[toonyank]

Um, no offence but that'a pretty horrible guide there... Lots of bike-specific assumptions, but more importantly it contradicts itself constantly- it tells you to use preload to set sag, but also that it's to be used for stiffness- then, when addressing too soft/too hard issues, addresses only damping and doesn't mention preload. It's not all bad but there's too much simplification, some actual out and out mistakes, and plenty of room for confusion. Lots of better guides out there. Ohlins, WP, Traxxion among others will agree with Sid Squid here, but you're absolutely right, you can find people stating it either way quite easily.

Yeh I just did a quick search for this. I was mainly pointing out what preload does to a compression spring in general

[ejohnh]

The force needed to compress a spring increases as the spring is compressed. So it is stiffer when compressed relative to when it is uncompressed. If the preload adjustment compresses the spring by a fixed amount then surely the effective spring is stiffer than when uncompressed.

Or maybe it's all in my mind. Wouldn't be the first time I have been mistaken - that I can admit to.

Well in fact I do have to admit that I was wrong in referring to 'stiffness' which is in fact a constant when relating to a spring. It's a measure of the force required to compress it a unit distance apparently.

Having admitted that I will insist that my rear suspension is now 'firmer' than it was before because It compresses less from its current preloaded position than it did before. So there is much less lolloping about going through bends. :smt023

[weazelz]

Having admitted that I will insist that my rear suspension is now 'firmer' than it was before because It compresses less from its current preloaded position than it did before. So there is much less lolloping about going through bends. :smt023

changing preload does have some secondary effects:

- changes rear ride height
- changes rear suspension geometry - which changes the rising-rate ratios & hence *may* make the suspension stiffer
- some other things I've forgotten

[injury_ian]

by increasing the preload you will be storing energy in the spring by compressing it, ie the spring wants to decompress so is applying a greater force between dogbone and frame, that effect makes it feel stiffer.

[weazelz]

...
nope, sorry, but that's not right

stiffness = spring rate [1]

people think that the rear end is "stiffer" because it compresses less, but this is beacuse the extra preload causes the suspension to sit higher in its stroke, not because the spring rate has changed (it hasn't)

if you go nuts with the preload you can cause the suspension to bottom-out on the compression, or top-out on the rebound, which again can be erroneously thought to be making the rear "stiffer" because you''ll either effectively have *no* suspension on bottom-out, or get kicked out of the seat on top-out


[1] all other things being equal - ie damping, etc.

[MeridiaNx]

Haha, now I have no idea what's going on. I've tried to get my head round the basics of suspension, preload, sag, rebound, compression damping etc. etc. Too many terms!! Now I'm even more confused :rolleyes:

But it has got me hunting round the forums for old info so I can finally try to twiddle with my setup and see how it goes before I consider the 'popular' front spring and oil change.

[ejohnh]

Haha, now I have no idea what's going on. I've tried to get my head round the basics of suspension, preload, sag, rebound, compression damping etc. etc. Too many terms!! Now I'm even more confused :rolleyes:

But it has got me hunting round the forums for old info so I can finally try to twiddle with my setup and see how it goes before I consider the 'popular' front spring and oil change.

Yep, I have had a gutsful of this too. Bottom line is that if you up the preload you decrease the amount the spring will compress for any given load - so it 'feels' like the spring is stiffer - honestly Sid, I know that in absolute terms the spring will always retain its stiffness coefficient.. I just wish I could say the same for the other thing :oops:

[MeridiaNx]

Right-o, so that means that seeing as most people complain about the front as being overly bouncy/soft i.e. compressing too much under bumps or braking (technical terms I know) the common adjustment is to increase the preload to make it a firmer ride....or at least that's how it sounds to me? I hope I avoided angering the suspension gods, I deliberately didn't mention the heretical 'stiff' word :D Probably got it wrong anyway though, ha!

Will have a gander tomorrow, and get a mate to help me finally set the sag. God I need to scrap some cash together to send myself on a weekend mechanic course or something, at least so I can do the basics with confidence.

[21QUEST]

The standard SV suspension as standard is the easiest thing to setup. My tip...and not being sarcastic...is to set the Sag and just ride the darn thing :p ;)

Seriously, if you have an SV with Preload adjustment just set the front Bike Sag(Sag without rider) to about 20mm-25mm. Set the bike rear Sag(sga without rider) to 5mm-10mm and that's it done.

I've got a 2000 SV650N and all I've done is change the oil to one with a slightly(and I mean slightly) higher viscosity, set the rear bike sag and that's it.

I haven't even bothered checking the front Sag as haven't got the time for at the moment to cut spacers so pointless checking it. Yes, it's still a bit soft on the low speed damping(read braking) but it retains acceptable high speed(read square bumps) damping.

I adapt my riding to what I've got and can still ride pretty swiftly. You have to be a bit smoother but that's never a bad thing anyways ;) .

What year is your bike?


Ben

[weazelz]

Right-o, so that means that seeing as most people complain about the front as being overly bouncy/soft i.e. compressing too much under bumps or braking (technical terms I know) the common adjustment is to increase the preload to make it a firmer ride....

no they don't, they fit firmer/stiffer springs to make it firmer/stiffer

[ejohnh]

no they don't, they fit firmer/stiffer springs to make it firmer/stiffer

So are you saying that preload is a waste of time weazelz? Because if I set my preload so that the back dips x mm less for a given load then I would say that preloading has given me a firmer suspension. Notice that I did NOT say stiffer.

It's good to argue.

[21QUEST]

So are you saying that preload is a waste of time weazelz? Because if I set my preload so that the back dips x mm less for a given load then I would say that preloading has given me a firmer suspension. Notice that I did NOT say stiffer.

It's good to argue.

No it hasn't given you a firmer suspension. Spring rate/damping rate is still the same as before ;)

Edit: Setting the preload(read sag) is not a waste of time as you'll be setting the points at which the suspension works but......(compression/extension).



Ben

[ejohnh]

No it hasn't given you a firmer suspension. Spring rate/damping rate is still the same as before ;)

Edit: Setting the preload(read sag) is not a waste of time as you'll be setting the points at which the suspension works but......(compression/extension).



Ben

"spring rate.damping rate" and second paragraph...

What a load of semantic tosh.. If it feels firmer and compresses less under my bodyweight then, by definition, it is firmer.. not stiffer, firmer.

Very good to argue lol!

John

[21QUEST]

"spring rate.damping rate" and second paragraph...

What a load of semantic tosh.. If it feels firmer and compresses less under my bodyweight then, by definition, it is firmer.. not stiffer, firmer.

Very good to argue lol!

John

Lol

Yeah it may feel firmer but it's not really firmer.....
True that you are probably more likely to shake your fillings out though :o :)

Firmer > ...not easyly moved/indicating firmness or resolution
Stiff > not easly bent/lacking in suppleness or flexibility/impeded in movement

synonyms of firm > STIFF, RIGID, INFLEXIBLE

:rolleyes: :p



Ben

[ejohnh]

Lol

Yeah it may feel firmer but it's not really firmer.....
True that you are probably more likely to shake your fillings out though :o :)

Firmer > ...not easyly moved/indicating firmness or resolution
Stiff > not easly bent/lacking in suppleness or flexibility/impeded in movement

synonyms of firm > STIFF, RIGID, INFLEXIBLE

:rolleyes: :p

Ben

mmm just as I suspected Watson - Semantic Pragmatic.. :smt023

[weazelz]

So are you saying that preload is a waste of time weazelz?

no, it's not useless, it's very useful if used *for its correct use*. which is not adjusting stiffness

Because if I set my preload so that the back dips x mm less for a given load then I would say that preloading has given me a firmer suspension. Notice that I did NOT say stiffer.

if you look closely, you'll see that it dips *the same*. it just starts from higher up

[ejohnh]

no, it's not useless, it's very useful if used *for its correct use*. which is not adjusting stiffness



if you look closely, you'll see that it dips *the same*. it just starts from higher up

Yawn - so for what is it's correct use pray tell?

Why is everybody so shy about saying what preload is actually for, if not for tightening up the suspension?

The dip is certainly less, end to end..

[21QUEST]

mmm just as I suspected Watson - Semantic Pragmatic.. :smt023

LOl

Not really semantics/pragmatism...real science to it man :confused: ;) .

Placebo is in effect I tell you :)


Ben

[northwind]

If it's standard SV parts, just fanny about with it till it feels good, it'll never be perfect and you've hardly got any adjustment anyway so don't worry about it. Perhaps should mention I've been drinking though, that may be influincing my advice.

But, don;t go for high preload "stiffness", because that massively impairs the bike's ability to deal with drops. It feels good over bumps, but unweight the front and bad stuff can happen as you're too close to the top of the travel. Doesn't sound too bad? Downhill in a corner, running wide, you may suddenly develop an appreciation for why you shouldn't have ****ed up your sag just because it feels a bit stiffer.

[northwind]

What a load of semantic tosh.. If it feels firmer and compresses less under my bodyweight then, by definition, it is firmer.. not stiffer, firmer.


Not true at all. Here is thought experiment. You have a comfy chair, when you sit on it it sinks down by 2 inches under your weight. One day, your fat mate sits on it and breaks it. Now, you sit on it and it no longer compresses- however, the seat's at the exact same height when broken as it was when compressed. This is what preload does.

What preload is FOR, is making sure your suspension starts in the right place. Suspension goes down as well as up- it has to deal with bumps sticking up, and holes going down. With too much preload, it can't deal with drops in road level as you're starting at the top of the travel. Roadholding suffers. And remember, each postive change in road level- bump- is usually followed by a negative change- the downslope of the bump.

Running wide in bumpy corners is a common complaint of SV owners, and it's often caused by compromised sag setup. I know of at least one person that's crashed because of this. The wheel hits a bump, but can't return to the road properly, and the bike "falls" towards the outside of the corner.

[injury_ian]

Pre-load adjustment
When a motorcycle's forks are compressed or extended, the fork springs inside them are under compression or tension, respectively.
Pre-load is an amount of additional compression force the springs experience when the forks are at a given position. When you adjust the pre-load, you are either increasing or decreasing the amount of that force.
When you increase the pre-load, you increase the additional force at any given position of the forks under compression. This causes the forks to extend more under any given external force than they would at a lower pre-load setting. Therefore, the forks have to experience greater external force before they bottom out, or reach the maximum compression travel.The pre-load can be used for suspension tuning.......

sounds like firmer suspention to me. :confused: not only that, my **** ... bottom.. tells me its firmer too!

[EC8010]

Than you for the explanation of pre-load, northwind; I will leave the suspension on my five-week-old bike alone.

[Sid Squid]

If it ... compresses less under my bodyweight

But it doesn't, that's the point.

[timwilky]

Oh dear, I cannot believe there are so many people who do not understand how the most basic suspension on their bikes works. Sid is quite correct, the stiffness or spring rate is constant. you cannot change it by anything but a replacement spring. All the preload does is pre compress the spring. The effect of this is to set the sag or point where the suspension is in its most optimised position given the load of the bike/rider.

On more adjustable forks you can then adjust the damping rates to control the compression and rebound rates. But without cartridge emulators on standard SV forks the rates are pre defined as a function of the oil viscosity and the available flow rate through the damper rods.

Having increased preload, you have defined the load that must be applied before movement within the forks occurs. The effect therefore is that additional load is required to cause the forks to compress, So not stiffer, simply less reactive to small induced loads.

I would suggest anyone with any doubts about suspension talk to Mr Fud. Although he is not a frequent visitor to this site, he teaches suspension for a living

[monkey]

Forkin ell. So to summarise should I just play with the turney thing on the forks and see if mine gets better? Should I do it with caution? A mechanic friend of mine twisted the rear shock adjuster thing two notches and asked if it previously kicked me out of the seat to which I replied yes and to which he replied that'll sort it. It did. Do I want kickey out of seat thingy for the track and which is better for track on the front? Turney thing in or out?

Finally what would happen if said turney things were at completely different levels on the forks?

It's very hard reading for us slow people.
8-[

[EC8010]

I'd just like to see if I've understood this correctly. Would I be right if I supposed that the purpose of the preload is to compensate for the differing weights of riders, so that when correctly set for a given rider, the suspension travel is midway between bottoming or topping out on its endstops, thus giving maximum capability over bumps?

[monkey]

Would I be right if I supposed that the purpose of the preload is to compensate for the differing weights of riders, so that when correctly set for a given rider, the suspension travel is midway between bottoming or topping out on its endstops, thus giving maximum capability over bumps?

Reckon you got that spot on! That's how I've always understood it. Well is that right?

[SV Muppet]

Timwilky is absolutely right. Preload does exactly what it says, it pre loads the spring and does NOT change the spring rate. It's purpose is to put the suspension in the useable range of it's travel so that it neither bottoms out or tops out.

[pilot]

Any suggestions on which brand fork emulator is best?

[Tim in Belgium]

I'd just like to see if I've understood this correctly. Would I be right if I supposed that the purpose of the preload is to compensate for the differing weights of riders, so that when correctly set for a given rider, the suspension travel is midway between bottoming or topping out on its endstops, thus giving maximum capability over bumps?

Nope static sag with rider on board should be set to approx 30mm (some recommend 25 mm), i.e the suspension is approx 1/3 through its travel with 2/3 remaining.

[northwind]

Any suggestions on which brand fork emulator is best?

Cartridge emulators? Traxxion use Racetech parts for theirs, it's a different size of emulator but it works in the same way. After reports that the Matris kits were a true valve kit others are now stating that it's an emulator kit, not sure on those.

[Ceri JC]

After reading all this, I'm so glad I bought a shock with "only" preload, ride height, and a combined compression/damping dial. Imagine the shennanigans you could get up to with seperate compression and high and low speed damping :D

I can understand why people describe things as stiffer/firmer, but also understand why, from a technical POV, it's incorrect. As to good suspension, mine (most basic Nitron Racing one, with my own trial and error adjustment) is:
a) Vastly bettered than the knackered old stock shock.
b) Better than it was with the default settings.
c) Better than my abilites (I don't corner fast enough over bumpy ground to get it out of shape, so improvements are largely academic).

So I'm happy. Yes, I'm sure an expert could set it up so it was a bit better, but I doubt it would be significantly better/worth the money. What I'm not happy with, however, is the front end. I'm debating either a set of Matris fork internals, or the cheaper "oil and springs option". I had hoped to do them last month, but the car's service was more than I had planned, so it must wait another month, ho hum.