Fork adjusters

[Grant66]

Hi,

Whilst the bike is off road I thought I'd do the front fork oil change. The guide (on here) suggests making it stiffer using washers, but I've noticed a few adds around t' interweb for adjustable fork tops.

Do these do the same job? Are they recomended?

[northwind]

You can't make the front end stiffer with washers, that adjusts preload not spring rate, but apart from that yes, the two do the same thing. I'm not sure if I'd say recommended, I used mine for 10 minutes then never adjusted them again but it saved me a fair amount of trial and error doing it with spacers.

[Blue_SV650S]

You can't make the front end stiffer with washers, that adjusts preload not spring rate, but apart from that yes, the two do the same thing. I'm not sure if I'd say recommended, I used mine for 10 minutes then never adjusted them again but it saved me a fair amount of trial and error doing it with spacers.

Indeed, once the correct 'sag/preload (http://www.gostar-racing.com/club/motorcycle_suspension_set-up.htm#SET%20UP%20BIKE%20TO%20YOUR%20WEIGHT)' is set, there will be little need to change it again ... so having the luxury of an adjuster is probably a little superfluous after initial setup!!

Looks cool though 8)

[Grant66]

Ah, preload not stiffer.

More noob questions comming :-)

How do you know when its right?
Feels better or is there some sort of checks/calculations dependant on body weight.
Am I right in thinking heavier=more preload?

[Blue_SV650S]

Ah, preload not stiffer.

More noob questions comming :-)

How do you know when its right?
Feels better or is there some sort of checks/calculations dependant on body weight.
Am I right in thinking heavier=more preload?


Have a proper read of sag/preload (http://www.gostar-racing.com/club/motorcycle_suspension_set-up.htm#SET%20UP%20BIKE%20TO%20YOUR%20WEIGHT) ... its a good page and tells you ballpark figures and exactly how to test.

Basically if you want real ballpark, IIRC it works out you want the bike to have used ~1/3 if the available front travel (distance from fully extended/unloaded to just under the bottom yoke) when you are sat on the bike in the riding position and wearing all your gear!! You keep winding the preload up (put more washers in) until this is the case.

How much do you weigh in at??? Id say if you were >14st then you need to seriously think about getting new springs …

[Grant66]

Just over the 14st mark at present & with Christmas coming up its only going to get worse :lol:
What springs should I be looking at?

[Viney]

Bouncy ones

HTH

[Luckypants]

Just over the 14st mark at present & with Christmas coming up its only going to get worse :lol:
What springs should I be looking at?

got to racetech.com and use their spring rate calculator to get the spring rated for your weight. Also remember to factor in weight of gear.

In my case I wanted pre-load adjusters as I did 50/50 with/without pillion. Fit fork oil to suit the springs.

[Alpinestarhero]

Try heavier fork oil and see how you go with that.

BTW, nice topbox

Matt

[Blue_SV650S]

got to racetech.com.

Indeed

Without even looking, my guess is the 85 springs for you my friend* :)

* I might have some 85 springs for sale as it happens ;)

[embee]

I'm about 12st and intended to fit 0.80 springs (std are 0.709 IIRC), but where I got them from discovered they only had 0.85 in stock, so I had them.

For me at 12st the 0.85 are slightly stiffer than ideal, for you they'd probably be about right.

Higher viscosity oil and standard springs will be a slight improvement, but bite the bullet and get the springs, you'll never regret it, best bang-for-buck mod by far.

[Blue_SV650S]

..Higher viscosity oil and standard springs will be a slight improvement, but ...

Trying to increase the perceived 'stiffness' of forks by increasing/over damping, is at best ill informed and potentially dangerous way of doing things*!! :smt021

I'd never say that was an option ... even an inferior one .. :smt110

*ever heard of 'pump down'???

[northwind]

Embee knows stuff Blue ;) Prepare for a schoolin'.

[Grant66]

Thanks for the advice, so I should;

Change fork oil for better.
Fit fork top adjusters. (adjust when girlie is on the back)
Stiffer springs.


*ever heard of 'pump down'???

err....no what is it?

[Blue_SV650S]

err....no what is it?
A bit of google-fu will give you a fuller explanation, but it is essentially where over rebound damping means that the forks will ‘ratchet’ down as they cannot return quick enough for the next bump.

Admittedly this is normally a worry when you have separate compression and rebound damping (little compression damping lots of rebound), but depending on the series of bumps you could get this with using too heavy an oil weight/damping.

You can also get the forks to hydraulic lock if you just up the oil viscosity … this is your bigger risk in this stuation!!

Basically the oil/damping should match the spring, to stop it from .. well acting like a spring (a spring tends to go boing … boing … boing , you just want it to go boing! :D) … not used to make the suspension ‘stiffer’.

Assuming Mr suzuki matched the stock 10w oil damping properties to his stock ~7 springs properly, then the only time one should be changing his oil weight from that is if you up your spring weight … or large changes in ambient temp ...

[Grant66]

BTW, nice topbox

It was until a white van's mirror did this:

http://i21.photobucket.com/albums/b298/Gajjii/DSC00183.jpg

[northwind]

Basically the oil/damping should match the spring, to stop it from .. well acting like a spring (a spring tends to go boing … boing … boing , you just want it to go boing! :D) … not used to make the suspension ‘stiffer’.

Assuming Mr suzuki matched the stock 10w oil damping properties to his stock ~7 springs properly, then the only time one should be changing his oil weight from that is if you up your spring weight … or large changes in ambient temp ...

What is compression damping for then? Mr Suzuki didn't do a very good job of matching the stock oil either, 10W oil is appropriate, 12.5W is OK, the stuff used is thinner though, those who know reckon it's more like 7W.

[embee]

Of course you're right, Blue. ;)
Mismatching springs and damping doesn't fix anything!
I wouldn't suggest departing far from what Suzuki-san put in the pogos from new, but whether you have a 7.5W or a 10W isn't going to suddenly turn it into a widow-maker, plus check out the viscosity comparison charts
http://www.peterverdonedesigns.com/lowspeed.htm
and that bottle of "10W" could be nearly anything anyway.

I confess I did the cheapo route with mine early on and put in a mix of 10 and 15W, which did make a slight improvement over what it originally had, but doing it "properly" (but still the cheap route!) with springs+10W gives a vastly better solution at relatively low cost (short of emulators/GSX front etc).

Whether the original spring/damper combination was right is very debatable, mine was certainly boing-boing-boingy :D General concensus says it was about right for a 9 stoner.

There are/have been some suspension gurus on the site, it's not really my field at all other than the basics.

[drefraser]

You can't make the front end stiffer with washers, that adjusts preload not spring rate, but apart from that yes, the two do the same thing. I'm not sure if I'd say recommended, I used mine for 10 minutes then never adjusted them again but it saved me a fair amount of trial and error doing it with spacers.

Just a wild stab in the dark here but are there any parts left on your SV(s) that are as they came out of the factory? Why hasn't Mr Suzuki whisked you off to his secret volcanic island R&D department to develop the new improved SV? I'd buy one.

[northwind]

Answer- because all I do is copy other people's ideas :cool:

[Kinvig]

you appear to have something box-shaped stuck to the back fo your bike????

[Alpinestarhero]

It was until a white van's mirror did this:

http://i21.photobucket.com/albums/b298/Gajjii/DSC00183.jpg

Araldite should fix that

Matt

[Blue_SV650S]

As you well know northy, compression damping is there to slow the rate at which the spring is compressed; not to provide springiness! Basically if you put treacle in there you would struggle to ‘bounce’ the suspension as it is so heavily damped, I suppose it might give the illusion of being ‘stiffer’ … However in actual fact, stick a 10kg weight on the front and the nose of the bike will go down X mm just the same as if you put water in there … the only difference is that with the treacle it would take much longer to sink to X mm!! …

I suppose we are talking more about compliance than stiffness …

The SV is fitted with a damper rod mechanism for the damping, which is in essence a simple orifice setup, as such the damping force grows with the square of the velocity. So unfortunately although increasing the oil weight will improve slow speed damping and make the bike feel more solid at the front (as it sinks slower), the suspension would then tend toward not being compliant enough and ‘spike’ the rider on high speed (sharp) bumps.

The reason the SVs front end feels so poor is the damper rod setup … with damper rods you are dammed if you do, dammed if you don’t ;) or in non Bart Simpson terms, with damper rod damping, there is a large dichotomy between achieving acceptable high and low speed compression - it is this that is the nightmare, not the spring rate!! ;)

So back to the start, the only true way to 'stiffen' the suspension (and not sacrifice compliance) is to increase the spring rate (and then add the appropriate new oil to accompany its rate).

[Alpinestarhero]

SO blue, is there anything that can be done to mod the standard forks to make the damping better? Some people have mentioned emulators, what do these do and how effective are they?

Matt

[Blue_SV650S]

Yes, you need to get rid of the damper rods!!! :D

The better method of doing business is like you find in ‘cartridge’ forks – prolly best if you do a bit of goggle-fu - but essentially in a cartridge fork you have ‘petals’, these are little thin/flexible discs of springy metal that close a much larger damping hole. When you try and pass fluid through the hole/petal (compress the fork), the petal bends/opens allowing flow (hence movement) it provides the physical damping in much the same way as an damper rod at this point, but the beauty of using petals is that you essentially have a variable diameter orifice so you can have a much wider range of controlled operation!! Lovely!! 8)

Picture it, the quicker you you try and push fluid through, the more the petals will bend/open allowing faster flow of fluid, unlike the damper rod :( So, logically buy ‘stacking’ the appropriate stiffness petals you can get much better controlled high speed damping, whilst still allowing controlled low speed damping!!

An ‘emulator’ is basically just that, it is emulating this superior cartridge setup. In the SV you drill the damper rods to lessen/try and negate their effect and slot the emulator in there. The emulator has/is a little (yet basic) petal stack – job done!! … unfortunately its not as good as a full cartridge as the emulator only works on the compression damping (and is very basic/crude in design) …

[Blue_SV650S]

Picture speaks a thousand words!! ;)

Damper rod:-

http://www.fjmods.btinternet.co.uk/Pictures/DRFPic.gif

proper cartridge:-

http://images.motorcyclecruiser.com/tech/susp-diag2-md.jpg

Emulator:-
http://www.kneedraggers.com/image_storage/b/9a/b9a29f361dd5ff0bc3baeba8d4ede860_rough.jpg

[Alpinestarhero]

I see, thanks blue! How much more of a differance do they make, and coupled with some decent springs (e.g. ohlins), is it a good upgrade for the price?

Matt

[pmapp]

I see, thanks blue! How much more of a differance do they make, and coupled with some decent springs (e.g. ohlins), is it a good upgrade for the price?

Matt


I should be able to tell you after crimbo - thats my job for boxing day :flower:

[Blue_SV650S]

I see, thanks blue! How much more of a differance do they make, and coupled with some decent springs (e.g. ohlins), is it a good upgrade for the price?

Matt

Even with emulators, its no cartridge fork and still feels a bit ‘clunky’ … but it is a massive improvement over stock, you instantly feel more confident in the front!! 8)

If you are lacking confidence in the front, then it is ~£200 well spent!

I have emulators, 15w oil and 80 Racetech springs in my trackbike and – although not as planted as full cartridge forks I have ridden, it’s a very good setup!! – you have seen the antics I get up to on my trackbike, the upgrade kinda speaks for itself ;)

However I have totally standard setup in my roadibke … its rubbish, but it does all I need it to and I can’t justify spending £200 on something that is already doing all I need of it …

So essential upgrade – probably not – makes a noticeable difference when done – very much so :)

The choice is yours ;)

[Alpinestarhero]

Ta blue. I'll keep it in mind for the future when im finding limits; at the moment I'm finding that simply becoming a better rider gives me better feeling and response from the front, so I dont need to do any upgrading of the bike yet. Might want a new rear shock at some point, i expect thats a bit tired by now!

Ok, you can all go back to arguing and whatnot

Matt

[northwind]

As you well know northy, compression damping is there to slow the rate at which the spring is compressed; not to provide springiness! Basically if you put treacle in there you would struggle to ‘bounce’ the suspension as it is so heavily damped, I suppose it might give the illusion of being ‘stiffer’ … However in actual fact, stick a 10kg weight on the front and the nose of the bike will go down X mm just the same as if you put water in there … the only difference is that with the treacle it would take much longer to sink to X mm!! …


Yup, but that's still relevant, since rate of reaction to a force is critical in a fork... If you load up the front by, say, 50N on braking in one second, a fork with 5W oil will dive more dramatically and uncontrollably than a fork with 20W oil (I know you know this btw, I'm soliloquying to the audience :smt003) And when people talk about the forks being too soft, generally it's this reaction which they're most bothered by, since it feels terrible and it knackers your traction. Most people couldn't care less how much the bike compresses under your weight (though of course it's important! It's just not the thing most folks notice, which is how you get people with far too much preload sitting right on top of their travel)

But of course, sometimes you want the fork to react faster- if you load it up the same by riding over a rock you want it to get out of the way. So here your treacle would be a complete sod, the event it's reacting to is over long before it can fully react and you end up with the whole bike kicking. Again, impairs your grip, just as an overstiff fork would. So you want a fork that's resistant to braking dive but pliant to impact.

And then of course, you've got the rebound damping, which is what Blue was talking about earlier- with the SV forks the damping both ways is controlled by the oil, change the oil alone and you increase both compression and rebound damping, so the fork returns slower. And then you get what I've always called packing, but what blue calls pump-down, the next event happens before the bike's recovered from the last, and it ties itself in knots. Get that on the rear, and you have the best recipe for a tankslapper. Get it on the front and you have a huge loss of grip among other things. It's bad news. Increase the spring rate though, and the increased damping is offset against the fact that the fork pushes back harder.

But... All about finding a balance. If the stock oil wasn't underdamping the front as standard- and personally I think it is- it certainly is once it's been in there for 10000 miles. And as Embee said, not all fork oil is equal, 2 different 10Ws may act totally differently. I think we put Bel-ray in one, and Silolene in another, and you really could feel the difference. I reckon you can increase the damping enough to make a difference without causing severe problems, though. If you go nuts and fire in 20W or even 15W, expect problems, but a fairly viscose 10W or a light 12.5W could work out well.

That said, springs are only £70, that's less than most cosmetic mods and it makes the bike work. It's not a mod, it's a correction, it's just like buying shoes the right size.

This message is too big, I'll make another ;)

[northwind]

So, emulators. They're ace. I pretty much agree with every word Blue said up there. Fairly simple, not externally visible, quite effective. The only sort of cavea I'd put on it is that I did my entire GSXR front end swap for less than a set of springs and emulators, and if you're the right weight for the stock GSXR parts there's no comparison there, you don't have to be fast to benefit either (as anyone who's seen me ride knows!) If you're heavier, you have to chuck money at GSXR forks to get them to work right for you too, for a big'un emulators and springs set up right is better than a true cartridge fork with totally soft springs.

But, first things first, springs and oil is pretty cheap, it's very effective, it's simple to do, and if you do decide to upgrade to emulators afterwards you don't lose a penny as the springs will still work. I'm not going to say it's essential, but it's a shame to have a £4000 bike not working properly for the sake of £100 worth of parts.

[Alpinestarhero]

I've learnt more about compression damping reading this thread than I have in reading magazines and MCN for the past 11 years.

So, next...rebound damping!

Matt

[Blue_SV650S]

Rebound has been touched on above, but in a nutshell, rebound damping is there to control the rate of the springs return – you imagine a spring fully squashed then suddenly let go … PING!!!!! :D … not good … tame that Ping with rebound!!!! 8) … (if only we could tame our .org member Ping??!! :D)

There will be tones of stuff on the net about this if you are interested.

This website (http://www.gostar-racing.com/club/motorcycle_suspension_set-up.htm) is referenced quite often on here, a good read should answer your above question (and then some). :)

Give it a read and if you need anything clarifying further, then post it here and I am sure the .org collective intelligence should be able to help :)

Oh and northy, yep, agree if the oil is not the correct weight to start with then changing would benefit things!! 8)

I was just pointing out that if you are 18st, your forks problem is not best solved buy running stock springs, but with ‘crude’ oil to stiffen!!! :D

[Alpinestarhero]

Oh yea, gotcha there blue. I've never thought about suspension and springs before and stuff, i know its all there and what it does but never the full dynamics, hence why im only just learning now.

You guys should teach!

Matt

[Blue_SV650S]

Oh and a good way to 'stiffen' the front end, but yet retain initial compliance is to reduce the 'air gap'…

Think of the forks as a sealed unit, after setting the stock oil level, there is some air in there between the top of the oil and the cap. When the forks are compressed, the area inside the forks is effectively reduced!! Therefore this bit of air is also compressed, and compressed air acts a bit like a spring!! – i.e. it wants to return to its former state and therefore provides a force!! :)

Reduce the initial amount of air, keep the same travel, that air gets is compressed more, it therefore has a greater return force 8)

What is also cool about using air gap is that it is ‘progressive’ you can have nice softer springs that won’t be allowed to ‘bottom out’ as near the end of the stroke the air compressions contribution is significant enough to help out!! :)

Before everyone goes filling their forks to the top … ;) … you obviously need a bit of air in there else the forks would jam solid!! ;) Suppose if you filled the forks to the brim when fully compressed and with springs in (not sure how you would do that!! :D) then that would be the minimum air gap you could run 8)

[northwind]

I was just pointing out that if you are 18st, your forks problem is not best solved buy running stock springs, but with ‘crude’ oil to stiffen!!! :D

Aye, totally agree with that, it probably seems like a logical extreme to some too :rolleyes: There's a guy on SVRider, who will remain nameless, who's convinced that there's no need for emulators, cartridge forks, all you need is a set of .9 springs and 30W oil. He weighs 70 kilos. Why not just dispense with the forks and use a stepladder? But because it doesn't dive on the brakes, he thinks it's great.

It all sounds a bit academic to some, but I know at least one guy on this forum who's crashed because of a bad shock setup (far too much preload, right hander with a heavy camber and a ripple in the tarmac, wheel skimmed across the surface and chucked him into a ditch. Again, naming no names)

[zadar]

But of course, sometimes you want the fork to react faster- if you load it up the same by riding over a rock you want it to get out of the way. So here your treacle would be a complete sod, the event it's reacting to is over long before it can fully react and you end up with the whole bike kicking. Again, impairs your grip, just as an overstiff fork would. So you want a fork that's resistant to braking dive but pliant to impact.

with cartridge fork you can tune brake dive to degree.

[Blue_SV650S]

.. i know its all there and what it does but never the full dynamics, hence why im only just learning now

Speaking more generically here, I think that it must help a rider to improve their riding if they understand - at least to a reasonable degree - how a bike works 8) You can certainly detect better if your bike has a problem and catch it before it catches you ;)

Aye, totally agree with that, it probably seems like a logical extreme to some too :rolleyes: There's a guy on SVRider, who will remain nameless, who's convinced that there's no need for emulators, cartridge forks, all you need is a set of .9 springs and 30W oil. He weighs 70 kilos. Why not just dispense with the forks and use a stepladder? But because it doesn't dive on the brakes, he thinks it's great.

It all sounds a bit academic to some, but I know at least one guy on this forum who's crashed because of a bad shock setup (far too much preload, right hander with a heavy camber and a ripple in the tarmac, wheel skimmed across the surface and chucked him into a ditch. Again, naming no names)

To me if one wants to ride well and faster, there gets a point where you need to have a bike that behaves itself ... changing settings arbitrarily or without an understanding of what you are doing is likely to end in tears!! 8-[ But also suspension settings are a very personal thing, if Mr SVrider likes his forks to act as if they were made out of angle iron, then good luck to him!! ... I also think it is a bit of a joke when you get someone else to set your suspension up for you ... unless you give them a very detailed briefing, how the hell are they going to get it to ride how YOU like it?!!? ;)

Being able to ride the bike 'feel' what is going on and then make educated adjustment has to be the way forward??

Suspension is a black art, but the SVs simplicity and lack of adjustment actually makes the job of tuning your suspension to your needs so much easier ... 8)

[zadar]

Oh and a good way to 'stiffen' the front end, but yet retain initial compliance is to reduce the 'air gap'…

it only does in last part of travel and mostly used just to keep forks from bottoming.personally I dont like any progression,reason we use linear springs.
you can get same with selecting correct spring.or lengthening travel buy getting rid of hydraulic lock piece.

[yorkie_chris]

You guys should teach!

They seem to be doing a pretty good job of that in this thread already :-P


with cartridge fork you can tune brake dive to degree.

Thats the point of them isn't it? To be able to set some difference between high and low speed compression damping, or at least keep the level of damping the same rather than the square law that results from fluid flow through a compression hole in damper rod forks.

[zadar]

dive is separate from low/high speed.I am not talking about adjusters for damping.

[yorkie_chris]

Surely dive is the forks compressing, so any control of dive must be done by increasing the level of damping?

Are you meaning anti-dive systems which change this by action of the brakes' hydraulics?

[zadar]

yes,it is increase of damping but not one you thinking off.you want adjusters in range,you slow down dive internally.newer generation of forks has midvalve but there are other ways.
anti dive system of past is something that does not work.you dont see it any more.there are many ways to stop forks from diving but most dont work to good because they screw up rest of movement.

[Robw#70]

An ‘emulator’ is basically just that, it is emulating this superior cartridge setup. In the SV you drill the damper rods to lessen/try and negate their effect and slot the emulator in there. The emulator has/is a little (yet basic) petal stack – job done!! … unfortunately its not as good as a full cartridge as the emulator only works on the compression damping (and is very basic/crude in design) …

The low speed compression damping on an Emulator is controlled by the bleed hole in the centre brass washer that is under the spring and high speed is controlled by the spring force on the same washer/top hat.
The pre-load and rate of the emulator spring determines what point the damping crosses over from low to high speed.
The shim in the middle of the emulator is just a check valve to allow oil flow on the rebound stroke.

There is a pretty large amount of adjustment available from an emulator, with different spring rates, oil weights and bleed sizes, they are very good at what they are intended for.
A cartridge gives alot more scope for adjustment and control, but for a simple design the emulator performs really well.

[Robw#70]

yes,it is increase of damping but not one you thinking off.you want adjusters in range,you slow down dive internally.newer generation of forks has midvalve but there are other ways.
anti dive system of past is something that does not work.you dont see it any more.there are many ways to stop forks from diving but most dont work to good because they screw up rest of movement.

The new Matris forks now come with an external adjustable bottom out system, ive yet to get inside a set to see how they've done it.

Their cartridges have a bottom out cup on top of the compression stack with a valve that is shimmed for both directions on top(or underneath :geek:) the rebound stack.

[zadar]

shim stack on other side of rebound valve(replacing check plate)is called midvalve.
06/07 gsxr's come stock with it.but valves also have bleed holes.

[Robw#70]

No sorry I didn't explain very well, the bottom out cup is about 3" long and has a thread on it which is the nut for the compression stack and the rest of the stack/valve is normal shimstack and check valve.
The rebound valve stack nut is about 1" long with a simply valve on the end of it with a basic shim stack on either side of it, the rebound valve stack and check valve are as normal with no mid valve just normal check valve.

So the bottom out can be re-shimmed as required and I assume their forks have this setup but with an adjustable bleed.

I started to draw it but my pc died whilst in photoshop, I'll try and get some pics, they're beautifully made (over engineered), right down to the thrust bearing/finger preload adjusters.

[dirtydog]

Jeez it all sounds a bit complicated to me, think i'll just stick with my progressive springs, 15w oil, adjustable fork tops and just eat less pies!

[Robw#70]

Oops Sorry another thread Hijack:smt073

[zadar]

So the bottom out can be re-shimmed as required and I assume their forks have this setup but with an adjustable bleed.

yea,I heard of it.it makes no sense to me.
I dont like bottom out to begin with,never mind the one to shim :)

[yorkie_chris]

Any experience with the K1 (ish) GSXR600 forks? Any good?

[chazzyb]

I've got Racetech .85 springs, emulators and 15W oil in my forks. Two months ago, this felt good, especially the high-speed compression damping. With the temperature at the mo', the compression damping is now so hard it's almost dangerous...

[zadar]

Any experience with the K1 (ish) GSXR600 forks? Any good?
it is same basic cartridge as all of them.typical showa set up.97 is only one that is different in not having external compression adjuster.
if you dont mind none inverted forks they are great.

[Blue_SV650S]

.... There is a pretty large amount of adjustment available from an emulator, with different spring rates, oil weights and bleed sizes, they are very good at what they are intended for.
A cartridge gives alot more scope for adjustment and control, but for a simple design the emulator performs really well.

Indeed they work well when you have them set up, but are still more basic than proper cartridge forks, not only in operation/design, but when fitted they are not externally adjustable. This means a lot of faffing to get them where you want them and if any conditions change … it is forks apart time!!! Most true cartridge forks have at least some external adjustment on them!

[Loser]

Very interesting thread. am i correct in saying that changing springs is only required if suitable sag cannot be achieved with stock? i notice most people seem to change spring and oil together and possibly put in emulators also. I'm not impressed by the damping with stock especially if i increase the preload to achieve the correct sag (because obviously rebound becomes a little quick), so i guess if i put some heavier weight oil in i might help to solve that particular problem but i wonder are more people than is necessary changing fork springs when damping is really the problem (i accept that the fork springs have a low k value for many people)

[Blue_SV650S]

Very interesting thread. am i correct in saying that changing springs is only required if suitable sag cannot be achieved with stock? i notice most people seem to change spring and oil together and possibly put in emulators also. I'm not impressed by the damping with stock especially if i increase the preload to achieve the correct sag (because obviously rebound becomes a little quick), so i guess if i put some heavier weight oil in i might help to solve that particular problem but i wonder are more people than is necessary changing fork springs when damping is really the problem (i accept that the fork springs have a low k value for many people)

Yep, it is the rider sag that is important here. as a rule of thumb, if you are say 8 to perhaps 11st you will prolly be fine with the stock springs (look at the racetech website and use the calculator for your bodyweight to be sure). If you are 12st+ then you probably need to be looking at new springs to do things properly.

Remember 'preload' doesn't stiffen the spring (this is a common misconception). Its basically the same as if you stuck a weight on the nose of the bike (more preload - more virtual weight).. as an example lets say you upped the preload equivalent to 5kg weight on the nose of the bike ... or if you like added 5kg to yourself in pies ... that in no way makes the suspension 'stiffer' ...

With a spring change, the Oil is changed to try and compensate/raise the damping resistance for the extra force in the spring.

As others have said, increasing the oil weight slightly with stock springs can make the bike feel better as (from what they are saying) its under damped for the stock spring.

[Loser]

maybe somebody with a trained eye could compare these "damper rod kits"
http://www.traxxion.com/store/detail.asp?product_id=SVDR
from Traxxion for $249 say with the Matris F05 KE or SE kits http://www.matrisdampers.com/
are all of these just non adjustable emulator based kits? it would be nice if they even added an internal adjuster as on some mountainbike forks
thanks

[northwind]

Zadar can give you a better answer on the Traxxion kit I think, and Rob's your man for the Matris kit... But basically, Traxxion use a slightly different Racetech emulator than normal, and also include more precisely made damper rods to replace the stock ones. It's just as adjustable as the normal RT emulator kit, though all internal.

I don't know much about the Matris one, or rather, I've heard about 4 different contradictory versions, some people say they're a full cartridge kit, others that it's an emulator, PDQ have given different answers to different people if what you read on SV Rider is correct, and the Matris site is pretty confusing too.

[zadar]

Very interesting thread. am i correct in saying that changing springs is only required if suitable sag cannot be achieved with stock?
no.there is difference between right preload and to much or to little preload.
correct way is to get springs to match your weight as close as possible first.than adjust preload.
basically there is range of how much preload you want to use.
it does not change rate of spring but it moves travel.what you gain on one end you loose on other.

[zadar]

I have not seen matris one but I believe it is basically same deal except they use shim stack instead one plate.
traxxion modifies 41 emulator to work with curvy forks,they use different plate and different size bleed hole.their damper rod seals better on new gen sv so thinner oil can be used.thinner oil is better and more consistent.rods are preset with holes so no drilling is required.

[Robw#70]

This is an SE Kit for the SV:-
http://muchos.co.uk/members/robw/Fork F05 SE (Large).jpg

I'll try and get a better pic of the valve, it basically plugs inside the damper rod, the top part above the spring is just a machined preload spacer and a new cap.
http://muchos.co.uk/members/robw/Fork F05 SE 1 (Large).jpg

The confusion with the cartridges/springs is they do both:smt067

The 'K' kit is basically a set of springs and new fork tops, some have an insert for the top of the damper rod, ive not fitted these to an SV yet and I haven't checked, but they're £150>£170, bit dearer than ust springs but you do get fancy tops.

The 'SE' kit is pictured above and they retail at £300

[zadar]

only important part there is valve pictured on end of spring.does it have shim stack or just blow off washer.
rest is bling :)

[zadar]

problem with all this kits I see is that none is doing anything for rebound damping,which is in my opinion more important than compression damping.
at which point you got cartridge kits.
I actually have(in my head)design of valve like emulator that would do both but problem is cost of developing and producing something that market is not there for.easier to just buy cartridge or swap forks :)

[Robw#70]

The valve has a shim stack for compression and rebound, it uses alot thinner oil so the damper rod has little effect

[Alpinestarhero]

Heres something I hate; in the cold weather, my forks seem firmer and the feelign from the front is more vauge. I assume the fork oil is cold so more viscous.

It feels wrong

Matt

[Blue_SV650S]

Heres something I hate; in the cold weather, my forks seem firmer and the feelign from the front is more vauge. I assume the fork oil is cold so more viscous.

It feels wrong

Matt

Yep, that is exactly what it it :riding: ... also the tyre will be less flexible ... :(

[Alpinestarhero]

Yep, that is exactly what it it :riding: ... also the tyre will be less flexible ... :(

I can tell the tyres are odd, the front feels like its flat, but a quick wobble side to side shows it isnt

Winter riding is odd

Matt

[Blue_SV650S]

I can tell the tyres are odd, the front feels like its flat, but a quick wobble side to side shows it isnt

Winter riding is odd

Matt

:bigsmurf:

[northwind]

WIth the 15W oil I had in the standard front, on a really cold morning it used to be like having iron bars for forks, for the first few minutes at least. Drop off the high kerb outside my house, CLANG!

[yorkie_chris]

WIth the 15W oil I had in the standard front,

Your bike? Standard parts?

Lol! Pull the other one!


On a serious note is the thickening of oil in cold weather still as noticeable with cartridge forks? (I think the SRAD600 ones I've ordered take 5w)

[northwind]

Hey, it came nearly standard you know, it's not just sat in the garage for 4 years. Honest.

Hmm, as for the cartridge forks, if it happens it's not to such an extent that it's jumped out- but then as the weather gets colder I get slower and more cautious anyway so changes in feel wouldn't neccesarily be obvious. So I'm on the fence on that one. No doubt there are measurable differences but do they affect us day to day? Not me, really. And we don't exactly get extremes of heat up here :cool:

[Loser]

i wonder if there is much difference in feel with 15wt oil in otherwise completely standard curvys compared to pointys seeing as the forks are showa on the pointy but different brand on the curvys

[yorkie_chris]

Parts are pretty much interchangeable though, can't be too much difference.

[yorkie_chris]

I like the exchange rate at the moment.

Head bearing to fit me a gixxer stem - £23

Cheaper than a replacement SV one!

[zadar]

The valve has a shim stack for compression and rebound, it uses alot thinner oil so the damper rod has little effect
I like to see it.I wonder how it refills.

[zadar]

Parts are pretty much interchangeable though, can't be too much difference.
springs are only thing interchangeable between two forks :)
cartridge forks also change on cold weather but much less.

[yorkie_chris]

My bad. :oops: