Stiff front forks.

[daveb]

Been having issues with my forks recently on my SV650s (K7 pointy).
I have owned the bike from new (bought in March 08) and ride it all year.

Now I'm aware that the suspension on this bike is of a 'budget' nature and my forks have 'clonked' over heavy bumps since new but in the last few months, as the weather has turned colder, the forks performance has deteriorated notably and they seem quite stiff as if the oil viscosity has increased a lot and they clonk over very small bumps, and quite regularly.

Generally they seem a lot stiffer to move up and down on the brakes and the handling seems to have gone downhill a bit also.

Does anyone have any ideas what could be causing this - I'm aware that the oil is probably due for a change but I thought the oil would get thinner as it breaks down, it feels like it's got thicker!
Any advice?

Thanks

[Luckypants]

As it gets colder the oil will thicken, so you may be noticing it due to the average temperature going down. Other than that, there may be some gunk clogging up some of the damping holes if it needs changing - drain, pump some paraffin though to clean the forks, drain, refill with fork oil of choice and they will be much better for it.

[daveb]

Thanks for your response :o) Is this a fairly straight forward proceedure - can you change the oil with the forks in situe? Thanks

[Biker Biggles]

You need to take them out and turn them upside down to get the oil out.Just a thought but could your handling issues be caused by something else?Tyre pressures or head race bearings can make the front feel vague and odd.

[Typhoon]

Stiff forks on an SV... Don't knock it. :-D

[flymo]

pop along to my place with some fork oil and biscuits ;-)

[-Ralph-]

You've had the bike from new and never done anything to the forks, and they are too stiff? Unusual, something is isn't right. The clonk is caused by hydraulic lock as the oil stops flowing through the damper rod.

Take the fork apart and inspect, replace with new oil and new progressive springs, or stiffer linear springs would be an improvement. Choose the oil you use by it's cst@40 degrees rating, NOT by it's watt rating. You want between 35 and 45 cst@40.

[danf1234]

You are lucky to weigh 4 stone. Cos that's what standard SV forks are set up for!

[Spanner Man]

Choose the oil you use by it's cst@40 degrees rating, NOT by it's watt rating.


Blimey! I never knew fork oil was electric! :D

[thedonal]

Blimey! I never knew fork oil was electric! :D

It's not.

But Friends are.

[-Ralph-]

Blimey! I never knew fork oil was electric! :D

Yeah, yeah, 'weight' rating, but it's abbreviated to WT and most people pronounce the abbreviation 'wut' or 'watt' rather that say 15 weight :rolleyes: Lazyness I know.

[embee]

I'd recommend Silkolene PRO RSF fork oil, it has one of the best viscosity index (VI) numbers around, i.e. it doesn't change its viscosity with temperature as much.

Refer to the good old fork oil bible (http://www.peterverdonedesigns.com/lowspeed.htm) , check out the table about halfway down listing fork oil numbers, compare viscosity and VI and pick one you want.

[punyXpress]

In this frrrrreezing weather, are you sure it aint the mayo in the legs freezing solid?