SV Front suspention issue

[sl0th86]

Ive only had the bike a few days and the front end is so bouncy and soft it feels like its going to bottom out everytime i touch the front break! (im guessing its stock) what is the best/easiest/cheapest way to solve this problem and how has everyone managed to do it? Im kinda new to the SV so would be cool to get everyones opinions on it. Thanks!


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[tom_e]

Get some linear springs suited to your weight and change the fork oil to something decent like silkolene rsf

[sl0th86]

Yeah thats one of the first things that come to mind but im guessing its a big job? Anyone have any links to some cheap springs????


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[Bibio]

what year is the SV you have?

what do you weigh?

[sl0th86]

Its a curvy 2000 model and i weigh about 14stone with gear on


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[carelesschucca]

I'll guess that the fork oil has never been changed and you could probably do with a suspension service.

It's not a difficult job if you have a front paddock stand or some other way of taking the weight off the front (it can't be hard a chimp like me can do it using a Haynes Manual)

Last time I changed the oil on an SV of that age it hadn't been touched and the smell off it as it was poured out made me wretch. Once it was done it changed the front end.

[sl0th86]

Ahhh yeah maybe! Is it worth just replacing the oil first and go from there? I'll look into it a bit more and see if i can do it myself lol


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[tom_e]

No point in getting it all off and only doing the oil, drop some new springs in while it's all in bits anyway and it's job done.

[Bibio]

so 13st without gear.

you need .90 springs £89 http://www.ebay.co.uk/itm/SUZUKI-SV650-1998-2002-35-315-K-Tech-Fork-Springs-/171968628761?hash=item280a210819:g:cb4AAOSw9mFWG7K v
RSF 7.5wt oil £12.50 http://www.ebay.co.uk/itm/Fuchs-Silkolene-RSF-7-5-Motorcycle-Motorbike-Fork-Oil-1-Litre-/131533869662?hash=item1ea007925e:g:NgsAAOSwu4BVuPM t

to truly make the front end better you will need emulators £80.

or just do what most people think is right and increase the oil weight to 10-15wt and put up with a harsh ride. oil is for dampening, springs are for weight. the heavier the oil the more dampening and slower the forks react = harsher ride.

the biggest problem with the SV is rebound control and this is due to the check valves leaking like a sieve.

if you want a cheepish fix then get springs and oil then weld the rebound holes on the dampers to control the rebound better.

its an easy job as long as you have the tools.

[sl0th86]

Awesome thanks bibio! Im not sure if im having trouble with weight/springs or oil. It still has loads of travel its just really easy to compress the suspension hmm either way i think replacing the oil will be a good start! Haha


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[Bibio]

before you do anything wrap a cable tie round one of the fork legs at the dust seal then check it after a few days/weeks to see how far up it has travelled.

oil does absolutely nothing to help with the weight on the bike, oil only controls the rate at which the spring inside the forks compresses/rebounds. yes a refresh of the oil will make it 'feel' better but wont stop a 'soft' spring from letting the forks bottom out.

the stock spring rate is that for someone at a weight of 8st so adding an extra 5st is putting the spring rate way over what it was designed for which in turn makes it compress easier.

you could be lucky and someone might have already changed the springs and if so then a change of oil might just be the ticket.

your already taking the forks off so why not do it right.

[sl0th86]

Yeah true! I seeeeee, yeah i mite as well then, thanks a lot for your help mate much appreciated!


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[embee]

I have a curvey also, and recognise exactly what you describe. As Bib says, you need springs.


I'm 12st and use 0.85 linear springs from http://www.ktechsuspension.com/
I'd say for you the 0.9 would be just right.


I'd also definitely recommend Fuchs/Silkolene "Maintain" RSF oil, it has good technical specs. Personally I found the RSF 7.5W works quite well with the stock fork internals, it is actually more comparable to most other 10W oils (see table here http://www.peterverdone.com/archive/lowspeed.htm showing actual viscosities ). You may find it a touch soft with those springs on rebound, but I'd suggest it as a start before going to the 10W version. If you still have the original oil in there it will be like grey dishwater now.

[sl0th86]

Nice one embee im going to look into it and hopefully get it sorted! Its the only downfall i can think of on this bike!


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[Blapper]

If it's ok with you guys I will passenger on Joe's thread: I find the front soft under braking AND harsh over bumps so I am intrigued by these 'emulators'. As I am only 12 stone, I'd like to keep light suspension, but have less dive under braking. Is this possible? I've done the up-rate on oil viscosity on other bikes and it just doesn't cut it for me.

[sl0th86]

Looks like we both mite need new springs and oil? lol


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[Bibio]

a mentioned by tom in post 2 get linear springs and under no circumstances get progressive no matter how inviting the price looks.

you will never stop dive on damper rod forks unless you use some mechanical method of doing so such as emulators but you can control the rate at which it does by using different oil viscosities without the emulators.

linear springs to match your weight.
silkoline maintain rsf 7.5wt oil.
weld and dress the rebound holes on the damper rods.

doing the three things above will satisfy most people.

[Blapper]

What are 'emulators' Bibio?

[Bibio]

What are 'emulators' Bibio?

https://www.youtube.com/watch?v=j3QYZEQoN_M

[Blapper]

Thanks, looks promising for when I refinish mine.

[Blapper]

OK Guys, I have just witnessed first hand sl0th86's problem - and believe me he has a problem. My money is on his forks having no oil at all in them! Here is a quick and dirty phone vid to show it:

https://s.yimg.com/pw/images/en-us/video_encoding.jpg (https://flic.kr/p/Lg8B3R)2016-08-21 10.16.59 (https://flic.kr/p/Lg8B3R) by Andrew Hayes (https://www.flickr.com/photos/spraynpray/), on Flickr

Just click on the vid and run it from Flickr. It's corrupt at the beginning.

[sl0th86]

So i just went and got my oil changed in the front forks and yeah the old oil was rotten but not as bad as a i thought, its a curvy 2000 model and there was no damping rods what so ever just basicly spring and oil. Anyway ive put 15w in it and its a little bit better but still soft and bouncey! Whats next? I could get a harder spring but i thought thats just to do with weight/sag?


Suzuki SV650s 2000 curvy

[aesmith]

The spec may be different because mine is a pointy, but I've been through the process of changing oil, spring, and finally adding emulators. I found the biggest single improvement came from the spring change.

I'm lighter than you and went for 0.85 springs, so in your case the difference would be even greater.

By the way, not sure what you mean by "no damping rods", are there parts missing?

[sl0th86]

Ahhh yeah maybe! I dont think theres parts missing maybe they just dont have them for my year of bike? Not sure, either way i dont think theres any way of controling damping on my forks? Other than getting new/USD forks?


Suzuki SV650s 2000 curvy

[Blapper]

Joe: If there really is no damping mechanism in your forks, there are plenty of folks out there doing the USD thing so you would be able to get another set of forks or even just the parts you need but to be honest, having seen your bike, I can't believe there are no parts in there at all. Does it still bounce like it did round my place the other day, just using two fingers?

[sl0th86]

Yeah i just guessed the damping rods came in a bit later? Wether yours have them or not i dont know. I was thinking emulators? But i dont think my forks can have it? It kinda does but with more fingers now if you know what i mean haha well it is really basic forks but just didnt know it was going to be this much hastle haha


Suzuki SV650s 2000 curvy

[tom_e]

Did you actually strip the forks completely or just take the top caps off, pull the springs out and pump out the oil?
The damping rod is held in the bottom of the fork with a bolt so won't be visible unless you take them to bits.

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[sl0th86]

Ahhhh there you go, yeah didnt have them in complete bits, will an emulator work with these kinda damping rods? [emoji848]


Suzuki SV650s 2000 curvy

[glang]

yes the damper rod is right at the bottom held in place by a bolt that comes up from the bottom of the fork (you have to take the axle out to get access to it). You can fit emulators and theres plenty of info on here about how to do it.....

[tom_e]

Forget amount emulators for the moment and stick some decent springs in and see where you end up.

[sl0th86]

Ahhh i see ok thanks, would the springs actually help tho? Isnt that a weight/sag thing? Think im having damping issues? Im tempted just to get USD forks and be done with it but worries about fitting them lol


Suzuki SV650s 2000 curvy

[Bibio]

think about it..... if the springs are too soft no amount of oil viscosity is going to change that and if you try then you might end up with hydraulic lock. its one of the biggest misconceptions floating around on the internet that heavier oil is better when in fact nothing could be further from the truth.

there is a simple experiment to explain the difference the oil viscosity makes. get a bicycle pump and stick the end that the air comes out into a glass of water then pump, its easy to pump. now fill the glass with oil and then pump, its a lot harder to pump. now fill the glass with something like treacle and pump, ooohhh look you cant pump. well this is exactly what happens in forks with oil viscosity.

as i have said before springs are for the weight of the bike and rider and oil is to control the movement of the spring. bike/rider sag settings are the most important measurement. once you set bike sag then the rider sag dictates the need for a change of spring. once you have the correct spring you ONLY set bike sag as changing the bike sag also changes the rider sag. adding more preload to compensate a soft spring makes the spring top out when unloaded so you end up with zero bike sag.

[Bibio]

ooohhh and BTW adding a GSXR front end is not going to solve your spring problem, you still need the correct springs for you weight. all a GSXR front end does is give you fancy dampening internals that are adjustable.

[sl0th86]

Thanks bibio it does make sense when you say it like that, guess i should just try eliminating one thing at a time, next up is springs then? Would it be possible just to swap/change springs without taking it all to bits?


Suzuki SV650s 2000 curvy

[Bibio]

yes just pull the springs out slowly then put the new ones in (you might need to cut the spacer for the new springs). BTW how did you set the oil hight with the new oil?

if you have an older curvy that has not got preload adjuster you use the spacer length to set the bike sag.

[sl0th86]

Im guessing one spring at a time? No idea my mate done it for me, is it a bit better/firmer but still a bit bouncey and dont trust the front end round corners if you know what i mean


Suzuki SV650s 2000 curvy

[sl0th86]

Now that you mention it, he did say there is room for a little top up if need be. Guessing that'll make a difference?


Suzuki SV650s 2000 curvy

[Bibio]

room for a little top up... ermmmmm what.

no offence but your mate sound like he does not know what he is doing as you need to measure the oil hight without springs with the forks off the bike and standing straight up and down with the stanchion fully compressed. you also need to pump the forks up and down when adding the oil or you get air in them which then drops the oil hight as you use the bike which give a larger air gap leading to mushy forks..

or accept my apology and he does know what he is doing and done it right.

[sl0th86]

Oh haha is there a line where the oil should be? How do you know theres enough oil in them?


Suzuki SV650s 2000 curvy

[Bibio]

there is no line and you use an oil level tool to set the hight. the hight is in the workshop manual.

[sl0th86]

Ahhh ok cool makes sense now, i'll look into it and get the oil set right first! Im guessing that wont help either


Suzuki SV650s 2000 curvy

[embee]

No, you need some new springs. I think someone might have mentioned that before.

[Blapper]

sl0th86 isn't a heavy guy at 13 stone plus gear, I'm pretty surprised he would need heavier springs. He is a stone heavier than me and I certainly don't need heavier springs. When you compare his 'damping' (not) with mine, his bike must have a problem because it has almost zero damping. OK, it is possible that his bike has non-standard lighter springs in it, but that doesn't change the fact that there is no damping action. See my short vid above. Apply the front brake when you are moving it around by hand and it dives almost fully down and boings back up and down a bit.

[Bibio]

your video link does not work.

even at 13st your still a good 5st over the standard spring rate. ok so most people are happy with it but if your not then the only way to sort it is doing it properly, i very much doubt that its got lighter springs in the forks as the standard ones are rated for someone around 8st on a good day. problem is though that once you have sorted the front the rear shows its inadequacy.

[sl0th86]

Yeah i thought its damping im having trouble with as it does spring straight back up its just realllly easy to compress, thats true bibio as the rear seems fine to me so far! lol think i just need to man up and get a spring


Suzuki SV650s 2000 curvy

[tom_e]

Get 2 it'll work better :p:D

[sl0th86]

Hahah it sure would! lol


Suzuki SV650s 2000 curvy

[aesmith]

sl0th86 isn't a heavy guy at 13 stone plus gear, I'm pretty surprised he would need heavier springs.
I'm two stone lighter and there was a definite improvement when I replaced the standard springs with 0.85 linears.

[sl0th86]

Ok so im about to order some 0.9 k-tech fork springs, to replace them can i just pop the cap off and swap them while the forks are on the bike and on its side stand? (Baring in mind if i do one at a time) I dont have any stands at my place and does anyone know off the top of their head what size the nut is on the cap? Thanks


Suzuki SV650s 2000 curvy

[johnnyrod]

Can't remember 17/19mm? but try to chock something under the front as when you pop one out the other will sag much lower, and quickly enough to hurt you.

I'm 10.5 stone nekkid and the stock springs are too soft for me too.

[sl0th86]

Ahhh yeah as the front end will only be supported by 1 spring i get ya, sorry for all the silly questions im a mega n00b when it comes to suspension haha


Suzuki SV650s 2000 curvy

[Blapper]

Joe, PM me, you can use my ABBA stand and I have all the tools.

[Blapper]

You young guys prolly ride a lot harder than me :-)

[sl0th86]

Just a quick question about anyone with emulators, is it a guessing game with settings and have to keep taking forks apart to adjust them, or are there recomended setting for weight etc...

Cheers


Suzuki SV650s 2000 curvy

[Blapper]

Good question.

[maviczap]

Just a quick question about anyone with emulators, is it a guessing game with settings and have to keep taking forks apart to adjust them, or are there recomended setting for weight etc...

Cheers


Suzuki SV650s 2000 curvy

Yes it is a bit of a guessing game, but from the start it will be better than stock. Im sure there's threads on here about how to set them up.

[sl0th86]

Haha true! Yeah i'll do some research and see what i can find, cheers


Suzuki SV650s 2000 curvy