Been having issues with my forks recently on my SV650s (K7 pointy).
I have owned the bike from new (bought in March 0

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