Fork upgrade

[Born again]

I have read a lot on this site about upgrading the fork springs and oil.
I can understand that this mod can help to stop dive for track and fast road riding, but does this mod make a significant difference to the bike in normal (whatever that is) road riding, if so how is the improvment noticed.
I ask because after returning to riding after a long layoff the SV is far better than the old bikes I used to ride, and I have not had the pleasure of riding the likes of a K7-gsxr so I cannot compare a modern sports bike suspension with the SV.

[Born again]

Bump.................:-dd

[socommk23]

i done the springs and oil! generally made the bike handle better, dive less. better feed back through the bars and well worth it i think!

[jambo]

The springs in an SV's forks are generally agreed to be about right for somone of 9-10 stone, if you're significantly more than that you should find stiffer springs stop the front from bottoming out or using quite so much of the suspension travel during riding. If the fork oil is past it's best, you will tend to find the front end feels rather vauge in corners and such, changing it with the fork springs should make the front end feel a bit nicer.

If you do a search it's been covered a few times before and other people will have explained better than me.

in short if you're happy with it as it is it can't be that bad, many people want the front end to be more composed under hard and fast riding conditions and this is where using the forks off other bikes such as GSXRs starts being suggested, but I'd doubt you'd be after that if you're happy how it is now;)

[Stig]

I'd say the same as Jambo. Changing the springs does make a difference. Even if you do not think that the front end is limited now, changing the springs and oil and you will then realise that indeed it was not brilliant before.

Changing the oil to a heavier cleaner oil will also help with the damping and make the steering feel more controlled.

I'd say it's the one best mod that you can make to the SV. That and a new rear shock.

[ejohnh]

I'd say the same as Jambo. Changing the springs does make a difference. Even if you do not think that the front end is limited now, changing the springs and oil and you will then realise that indeed it was not brilliant before.

Changing the oil to a heavier cleaner oil will also help with the damping and make the steering feel more controlled.

I'd say it's the one best mod that you can make to the SV. That and a new rear shock.

Hi,
(2003 registered sv650 K1 curvy)
I'm 13 stone and to coin a phrase "my front end is crap". are you talking about Ohlin springs? Are they difficult to fit?

[petevtwin650]

Not difficult, just time comsuming.

You need to take the fork legs off to change the oil, which you might as well do otherwise you'd be wasting your money on the springs.

Ohlins,Progressive or Racetech springs plus thicker oil.

[Stig]

There are two different type of springs that you can have. Linear and progressive. They give two different qualities to heavy braking.

Further, changing the wieght of the oil also makes a difference as previously explained.

There are several different companies out there that you can use. I have Hagon linear springs. I phoned them up, gave them the bike details, my weight along with my riding style and the types of road that I will be using my bike on. With all this information they will be able to supply you with the correct springs, spacers and oil for your requirements.

So long as you have a manual and a means of lifting the front end off the ground, you should be able to change the springs and oil yourself. The most important part of the change is to make sure that you get the air gap correct and level in both forks. I would expect it to take you three hours or so if you have never done it before. Once you have done it once I'm sure you could get it down to an hour.

[northwind]

I used the Ohlins ones, because they're easy to find, but they only do one spring rate- or, at least, most Ohlins dealers can only get one. Racetech, Sonic, Hagon, etc etc, can all do different rates, so you can get the right ones for you instead of compromising. As it happens, the Ohlins were spot on for me so that was fine.

It's a great mod... Reasonably cheap, pretty DIYable, totally reversible... And other than the oil you can get most of your money back on resale if you choose to upgrade further or you sell the bike. Plus, if you decide to upgrade further to emulators then you can keep the same springs. And it does make a real world difference. Don't expect too much, you still have basic suspension afterwards, but it's basic, appropriate suspension at least. I reckon everyone over about 12 stone could benefit from it, myself.

[Stig]

I reckon everyone over about 12 stone could benefit from it, myself.

I reckon everyone would benefit from it fullstop.

[northwind]

Depends really... Some people are the right weight for the stock springs... Though any older bike probably wants new oil by now as well, I swear the stock stuff is fish oil not fork oil, from the way it smelled in the forks I've done...

[zunkus]

I'm still on standard springs, weigh 71Kg and am 5'10". My brother's SV has Ohlins springs and thicker oil. Maltese roads are 20% potholed at best and bumpy so for normal riding I prefer my setup as they have some give though I've ridden better, but on better roads my brother's forks are noticeably better. Never been to England yet but from the pictures in mags I see that you have no reason to complain of your roads, ok I'm sure French/German roads are better, been there, billiard smooth and so clean. So given you ride in reasonably smooth roads and if you are over 71Kg (SV's springs are set for that weight so I guess I'm lucky) go for it.

[Born again]

Thanks for the info, I am just under eleven stone without riding gear so I suppose its borderline if I would get the benifit of new springs. I am going to change the fork oil, I have had the bike for eight months and dont know if the oil has ever been changed.
What weight oil would be the best for my weight.

[Stig]

If memory serves me correctly the bike as standard has 10 weight oil in it. If you feel that the bike could do with some more damping then try 15 weight. Either that or just stick 10 weight back in and see how it feels. Fresh oil may make all the difference.

If the oil in the forks is a milky grey and watery then it's doing almost as little as if there was water in there.

[chazzyb]

The problem with 15W fork oil is that it makes the front end very hard. Even for a fat sod like me. It may help the rebound damping but makes the compression damping very stiff and harsh.

[Stig]

The problem with 15W fork oil is that it makes the front end very hard. Even for a fat sod like me. It may help the rebound damping but makes the compression damping very stiff and harsh.

Well I have Hagon linnear springs and spacers, 15w oil and the rider sag set up correctly for my weight and think that the front end works perfectly for me.

I guess it's a case of what ever works for you is fine.

[21QUEST]

The problem with 15W fork oil is that it makes the front end very hard. Even for a fat sod like me. It may help the rebound damping but makes the compression damping very stiff and harsh.
Well I have Hagon linnear springs and spacers, 15w oil and the rider sag set up correctly for my weight and think that the front end works perfectly for me.

I guess it's a case of what ever works for you is fine.

On balance I'll tend to agree with chazzyb as the damper Rod design of the SV will tend to make the high speed damping harsh as you increase oil vicosity.

In saying that an increase spring rate on the other hand might mask(in a way) the harshness as takes more force to compress the springs. The 15W helps in conttrolling the rebound of the higher spring rate. For sharp bumps I'm still not sure how good the 15W will be though still. Another thing is the brand of oil/specific oil of a brand you are using. 15W doesn't really mean much. Some are close enough in actual viscosity but some vary quite a bit.

I do agree even a change of fork oil will inprove the overall working. On my naked with standard springs which are slightly progressive I'm using Putoline HPX 7.5W. Feels quite good. A good compromise between High and Low speed compression damping. The rebound is also pretty acceptable IMO. Use the standard air gap and if needed just add 5ml of oil at a time to provide a stronger air spring. It's all in the compromise I guess but for road use, you still don't want the high speed compression being too harsh.

For the standard springs I'll say at ,
Silkolene fork oil 10W(regular and NOT the RSF)...34.9 centistoke
Silkolene Pro RSF 7.5W....37 centistoke
Motul factory line medium 10W...36 centistoke
Motul Expert medium...35.9 centistoke

The standard oil is 33.3 centistoke


Ben