fork oil

[antony]

putting some k tech front internal springs in for minitwin racing along with 15 weight fork oil what i would like to know is how much oil to put in in ml cheers

[socommk23]

pick up the manual for the bike...should have the level of oil you need in the forks!

[jonboy]

I used to run with 15w oil but although it helps prevent fork-dive it also masks the SV's basic suspension traits (which is why some peeps prefer it) and didn't offer the same level of precise (for an SV) rebound and damping that going back to 10w did.


.

[Sid Squid]

Depends on which model of SV you have.

But you didn't say, so we don't know.

[antony]

its va k4 model also would anyone knoe how much pull thru in mm at the top of the yoke we be a good start off

[northwind]

I don't know what the manual says... But I would say it's not a magic number. You can vary the oil level in the same way that you can vary oil viscosity, preload and springs to get different effects.

Not that I did :)

[Blue_SV650S]

Ring K-Tech; to be honest you should probably be running 5w oil in there. Race damping is normally set up around 5w oil. The rationale being that 5w oil will thin less than 10w (or 15w) oil when hot, therefore you can keep more consistent damping properties over a bigger temp range.

As for level, book says:-

X, Y & K1 489cc (European models)
K2 478cc.

But the more accurate way is to measure the LEVEL

These are :-

X, Y & K1 104mm (European models)
K2 115mm

I don’t have the data for later models.

Again K-Tech should have all this info and might suggest their own levels (i.e. non stock levels to reduce/increase ‘air gap’ depended on their recommended base setup).

[Robw#70]

Ring K-Tech; to be honest you should probably be running 5w oil in there. Race damping is normally set up around 5w oil. The rationale being that 5w oil will thin less than 10w (or 15w) oil when hot, therefore you can keep more consistent damping properties over a bigger temp range.

As for level, book says:-

X, Y & K1 489cc (European models)
K2 478cc.

But the more accurate way is to measure the LEVEL

These are :-

X, Y & K1 104mm (European models)
K2 115mm

Again K-Tech should have all this info and might suggest their own levels (i.e. non stock levels to reduce/increase ‘air gap’ depended on their recommended base setup).

:shock: :shock: :shock: :shock: When the valving in the forks is efficient then 5w (or lower) is a good idea, but with something as crude as SV damper rods there would be next to no damping with 5W.

15W oil
130mm Air gap, forks fully compressed no springs
You can do it in the bike on paddock stand (but better with forks out),
Measure the airgap front and back of the fork leg (as oil level is at an angle) and 1/2 way between the difference between the two is your level

[Blue_SV650S]

:shock: :shock: :shock: :shock: When the valving in the forks is efficient then 5w (or lower) is a good idea, but with something as crude as SV damper rods there would be next to no damping with 5W.

15W oil
130mm Air gap, forks fully compressed no springs
You can do it in the bike on paddock stand (but better with forks out),
Measure the airgap front and back of the fork leg (as oil level is at an angle) and 1/2 way between the difference between the two is your level

Perhaps I misunderstood, but I thought he meant he was getting some K-Tech ‘cartridge’ internals … which basically replaces all stock internals. These I assume would be set up around 5w OIL, hence my post and reccomendation to ring K-Tech. If that is not what he meant, then that is ‘my bad’!! :D

[Flamin_Squirrel]

:shock: :shock: :shock: :shock: When the valving in the forks is efficient then 5w (or lower) is a good idea, but with something as crude as SV damper rods there would be next to no damping with 5W.

15W oil
130mm Air gap, forks fully compressed no springs
You can do it in the bike on paddock stand (but better with forks out),
Measure the airgap front and back of the fork leg (as oil level is at an angle) and 1/2 way between the difference between the two is your level

Perhaps I misunderstood, but I thought he meant he was getting some K-Tech ‘cartridge’ internals … which basically replaces all stock internals. These I assume would be set up around 5w OIL, hence my post and reccomendation to ring K-Tech. If that is not what he meant, then that is ‘my bad’!! :D

Fitting of emulators requires heavier oil, not lighter :wink:

[Blue_SV650S]

Fitting of emulators requires heavier oil, not lighter :wink:

This conversation sparked my curiosity, as to me it is illogical to build race damping around heavy oil. So I rang K-Tech myself, their ‘cartridge’ kits for the pointy come with everything (springs and damping) are £230+vat and use 10w oil. I am still a little surprised that what is effectively a race kit runs 10w oil, but 10w (not 5w or 15w) is what it is designed around!!

I suppose I could have asked him levels etc, but to be honest they seemed really rushed off their feet, so I wasn’t going to take any more of their time, especially as I don’t know if it is a cartridge kit that has been fitted to the bike in question!

So the water clears a little, but more details plz! :)

[21QUEST]

:shock: :shock: :shock: :shock: When the valving in the forks is efficient then 5w (or lower) is a good idea, but with something as crude as SV damper rods there would be next to no damping with 5W.

15W oil
130mm Air gap, forks fully compressed no springs
You can do it in the bike on paddock stand (but better with forks out),
Measure the airgap front and back of the fork leg (as oil level is at an angle) and 1/2 way between the difference between the two is your level

Perhaps I misunderstood, but I thought he meant he was getting some K-Tech ‘cartridge’ internals … which basically replaces all stock internals. These I assume would be set up around 5w OIL, hence my post and reccomendation to ring K-Tech. If that is not what he meant, then that is ‘my bad’!! :D

Fitting of emulators requires heavier oil, not lighter :wink:

Read his response again and I think you'll find Robw#70 did not make a mistake in his post :wink: . There is no mention of emulators being fitted as far as I can tell.

Cheers
Ben

[Flamin_Squirrel]

Well with the racetec emulators I fitted, you need to drill holes into the damping rods. I presume this is to reduce the compression damping effect of the rod, so the emulator can take over. Of course, this means that rebound damping is reduced, so you need heavier oil to compensate.

edit// whoops. Yeah sorry, you're not talking about emulators :oops: :oops: :oops:

[northwind]

I suppose I could have asked him levels etc, but to be honest they seemed really rushed off their feet, )

They were busy rebuilding my shock ;)

[Blue_SV650S]

I suppose I could have asked him levels etc, but to be honest they seemed really rushed off their feet, )

They were busy rebuilding my shock ;)

LoL, there was plenty of banging, crashing and swearing in the background, so probably you r shock yeah :lol:

[antony]

hi cheers everyone rang k tech 15 wt oil ok and 130mm to 135mm of air gap all i have done is swapped the springs

[Blue_SV650S]

Cool, all sorted then :) And yes, if it is just the springs, then you have original damping still and I misunderstood :)

To be honest I have heard a lot about K-Tech and people raveing about how good their ‘cartridges’ are. But when I was on the phone to the chap I said “So do you set them up for riders weight then?!” He said (not word for word, but this is essentially it) “We are in the progress of designing/making our own at the moment, the current kits we just buy in and only come in one type”. Supposedly they are set up for your ‘average’ rider (~13-14st). But for racing, ideally you want one built specifically round you.

This is what people like Harris will do for you. i.e. give you a set of springs for your weight and set the damping accordingly (based on 5w oil too). I have had this done on another bike (not SV).

I can’t believe the faster minitwin racers don’t have properly ‘sorted’ suspension, so there must be this sort of service available for the SVs?

[northwind]

Ktech willdo springs and valving to suit, it's those specific cartridge kits- which I think they get in from Ktech USA- which aren't available in a wide range. So if you're a 100 kilo rider, they maybe can't help, since the catridges are only available in the more popular "sizes". Also, i don't think they do one for the SV (could be wrong) they're cartridge replacement kits similiar to the Traxxion gold valves, which basically means they fit into cartridge forks. SVs have damper forks.

You're very hung up on 5W oil... A system designed to work with 5W isn't automatically better than 20W. It'll be less subject to temperature variation, though. Damper rod forks like the SV's work better with more viscous oils, that's more controllable. Cartridge type forks can pretty much use whatever they want, depending on setup and design.

I think a lot of the minitwin crowd use Traxxion cartridge emulators. Lots of stuff on the forum about these, so I'll not go into detail- they're not cartridge forks but they (as the name suggests) emulate some of the effect, giving better control of how the damping works. The oil viscosity still controls rebound damping, but the emulator controls compresison damping, so they're not both tied to the same components (with standard forks, if you raise the compression damping by going to heavier oil, you also raise the rebound damping)

They're a good value upgrade for standard forks, basically, along with appropriate springs.

[Blue_SV650S]

Ktech willdo springs and valving to suit, it's those specific cartridge kits- which I think they get in from Ktech USA- which aren't available in a wide range. So if you're a 100 kilo rider, they maybe can't help, since the catridges are only available in the more popular "sizes". Also, i don't think they do one for the SV (could be wrong) they're cartridge replacement kits similiar to the Traxxion gold valves, which basically means they fit into cartridge forks. SVs have damper forks.

You're very hung up on 5W oil... A system designed to work with 5W isn't automatically better than 20W. It'll be less subject to temperature variation, though. Damper rod forks like the SV's work better with more viscous oils, that's more controllable. Cartridge type forks can pretty much use whatever they want, depending on setup and design.

I think a lot of the minitwin crowd use Traxxion cartridge emulators. Lots of stuff on the forum about these, so I'll not go into detail- they're not cartridge forks but they (as the name suggests) emulate some of the effect, giving better control of how the damping works. The oil viscosity still controls rebound damping, but the emulator controls compresison damping, so they're not both tied to the same components (with standard forks, if you raise the compression damping by going to heavier oil, you also raise the rebound damping)

They're a good value upgrade for standard forks, basically, along with appropriate springs.

The kits he was talking about he said came from a European sounding company, not K-Tech USA. And yep, they do these cartridge kits for both curvy and pointy.

Just to clarify, I am not really talking about ambient temperatures effect on oil viscosity here. I am more talking about the heat generated in the oil/forks during use. Although for the road it isn’t as critical because the suspension doesn’t work as hard, as I have said prior, the thinner the oil the better when it comes to racing as you want the damping to change as little as possible over the duration of the race. i.e. a system set up with valveing for 20w oil could potentially be the same as one set up with 5w oil at the start of the race, so no, it isn’t automatically better. But as the race goes on and the oil temperature rises, the 20w oil viscosity will change more dramatically than 5w and that is when a 5w system is better. As the damping is so crude in the SV this would require a cartridge as this replaces both the spring and the damping, problem solved!!

As for emulators, surely the oil viscosity effects both compression and rebound?

If emulators and heavy oil is what the minitiwins lot use, well that it what they use!! and the results are impressive (i.e. laptimes), I am just a little surprised as it seems an inferior way to go about things. Is there a racers section on here so we can ask them??

[northwind]

Hmm, not sure who supplies the kits then. It turns out I was talking absolute rubbish when I mentioned K-tech USA, since there's not realyl such a thing, they actually sell K-tech UK products :roll:

You're right that viscosity effects both rebound and compresion with emulators. However, you also have adjustability with the emulator unit itself for compresion, so it's not solely affected by oil viscosity. Compression remains adjustable only by physically altering the rods, or by changing the oil

Minitwinners use all sorts of setups, basically whatever's legal and affordable ;)

[Robw#70]

Most people are using Racetech emulators, a few people early on wasted alot of money with R6 cartridge conversions, but a properly setup emulator works well and seems to match the 'Package' of a Minitwin.
Having ridden my carby on 750k5 front end at snett last week, the emulator setup on my K3 was slightly better and I will be revalving the GSXR forks to suit.

If you want to be picky about oil then why bother with 5W, just about all std 20mm cartridge forks run 5W, wheras a re-valved more efficient setup will use 2.5W or Racetech US-1 (inbetween 2.5 and 5) which is very consistant over a wide heat range.

[Blue_SV650S]

Most people are using Racetech emulators, a few people early on wasted alot of money with R6 cartridge conversions, but a properly setup emulator works well and seems to match the 'Package' of a Minitwin.
Having ridden my carby on 750k5 front end at snett last week, the emulator setup on my K3 was slightly better and I will be revalving the GSXR forks to suit.

If you want to be picky about oil then why bother with 5W, just about all std 20mm cartridge forks run 5W, wheras a re-valved more efficient setup will use 2.5W or Racetech US-1 (inbetween 2.5 and 5) which is very consistant over a wide heat range.

From your username, I presume you are minitwiner? So there you go, from the horses mouth, emulators are commonplace in the pack!! :)

And yes, indeed, why stop at 5w, the thinner the oil the better (as long as the damping is set for it obviously!) :)

Ryan Harris owns the current Minitwins lap record at Brands Indy … 51.83. With only 70hp? and now I know that the suspension is probably just an emulator mod job, I find that all the more impressive!! :)

I intend to take my road SV to the track at some stage, I’d be interested to see what times I can get on it :)

I noticed some of the minitwins are running racetech front, supercorsa rear, is there some logic behind this or just a cheaper option? … perhaps I ought to start a new thread rather than hijacking this one any more to answer my plethora of minitwin questions??!?! :D

[Robw#70]

MRO changed a few lap records last year, got in to the 51's myself, the only naked bike to do so :lol:
Brands Hatch (Indy) 0:51.52 16/10/2005 Graham English
Cadwell Park (Full) 1:38.49 20/08/2005 Matt Bond
Croft 1:32.02 16/04/2005 Bob Collins
Knockhill 0:57.71 31/07/2005 Matt Bond
Pembrey 1:02.50 18/09/2005 Matt Bond
Silverstone (National) 1:09.19 22/05/2005 Matt Bond
Snetterton 1:15.81 03/07/2005 Matt Bond

The racetech front offers a bit more grip and better wear, but they don't do a Racetech rear in 160, hence Supercorsa's

[Blue_SV650S]

MRO changed a few lap records last year, got in to the 51's myself, the only naked bike to do so :lol:
Brands Hatch (Indy) 0:51.52 16/10/2005 Graham English
Cadwell Park (Full) 1:38.49 20/08/2005 Matt Bond
Croft 1:32.02 16/04/2005 Bob Collins
Knockhill 0:57.71 31/07/2005 Matt Bond
Pembrey 1:02.50 18/09/2005 Matt Bond
Silverstone (National) 1:09.19 22/05/2005 Matt Bond
Snetterton 1:15.81 03/07/2005 Matt Bond

The racetech front offers a bit more grip and better wear, but they don't do a Racetech rear in 160, hence Supercorsa's

Bemsee need to update their lap record tables then :D

That explains the tyres thing then!!!

I have opened a new thread re suspension BTW :)

http://forums.sv650.org/viewtopic.php?p=499745#499745

[northwind]

Wee bit of a floow-up for the K-tech parts... I spoke to their representative at the Scottish Bike Show at the weekend who told me that the 25SSK kits are cartridge replacement only, and not avalable as cartridge kits for damper rod suspension. He said the only service they offer as a stock part (ie, not a complely customised rebuild with R6 or CBR600 internals, which he didn't recommend) for the SV is the emulators.

He also might have convinced me to get the 25SSk kit for mine ;)