Hi  Techno Peeples,   Stupid question probably -  I was thinking about changing the fork springs and oil in my  SV  as they are a bit soft , but ...   ... does anyone know if this can be done with the forks in situ,  or do I HAVE to remove the forks from the  bike ?     I have a siphon so I could siphon the old oil out  -  just  dont fancy  removing wheel / brakes / forks (never done that bit!!)   Thanks for your help as always  :-)   Chris                                                                                                                                                                             

Hi Chris, you can replace the fork springs with the forks in situ, but to replace the oil you need to remove the fork. As you need to invert and pump the fork to remove all the old oil from the fork. Hope this helps.
                                                                                                                                                                             

ye drop the forks then they can be inspected and cleaned...   good luck mate   kevkool                                                                                                                                                                             

Thanks guys - forks out it is !                                                                                                                                                                              

Bit late to the party here, but yeah, forks out,

I've swapped the springs with the forks in before and (being a smartarse) figured I could syphon the old oil out... In theory, yes, in practice.. Stupid idea! *oops*                                                                                                                                                                             

Thanks for the confirmation jools !  ;-)                                                                                                                                                                              

As they say defo forks out, if you are replacing springs with a progressive type the amount of oil may need to be measured as a distance from top of compressed leg rather than a volume poured in, so leg will need to be vertical.                                                                                                                                                                              

if you are using progressive springs it may be worth using a thicker oil too. i put hagon progresive springs, thicker oil and a bit more of it in the xj and it made a helluva improvement. still corners like a four poster bed but it's better than the pig on stilts it used to resemble.

oh yes and deffo forks out, it is so much easier.                                                                                                                                                                              

I went the other way xj, when i put progressive springs in the Raptor i used a lighter (2.5w) oil and it transformed the bike for the better. I suppose it depends on what you're going from, and what you're looking for.                                                                                                                                                                             

Progg springs and lighter oil in zzr, lighter oil transfers better in the valving.                                                                                                                                                                              

What about uprated springs with standard fork oil  ? Does that work, or do I need to put heavier oil in also ?                                                                                                                                                                              

For my tuppence, I believe it is dependant upon what was happening before, ie does it need this or just originals replaced.....weight etc....some bikes handle perfect as standard but obviously springs do wear out as it gets used more and the oil deteriorates.....

I know guys saying I need to change springs but all that it required was a change of oil and it was fine....

Not aquainted with that paticular bike but dont remember seeing a bike without oil drain plugs in the bottom of forks.                                                                                                                                                                              

I remember when bikes used to have little drain screws at the bottom of the forks!

You can still drain the forks without removing them Chris ... you just need to turn the bike upside down and shake it a bit!!

On another note (and a serious one) when Maxton did my forks, I was interested to learn that they no longer fit progressive springs!  And when Firefox serviced them for me, they said the same thing.

What I was told was that with progressive springs the soft part of the spring is immediately taken up and becomes coil bound as soon as you sit on the bike, effectively reducing the length of active spring.

And I was also told that as the springs compress the resistance rises at an increasing rate and as such any spring is naturally "progressive" anyway.  But that with a constant rate spring this progressive resistance acts over the full spring length.

Indeed Maxton replaced the cartridges and shim stacks in my forks for ones better suited to me and my style of riding, fitted lighter oil rather than heavier, which they said was for better control and firmer, constant rate springs.  Which is often the opposite to what diy-ers do.

And when Firefox serviced the shocks, they too altered the internals accordingly and then fitted lighter oil.

Makes sense when you think about it and I have to say the front end of the bike was transformed; less dive on the brakes, less static sag and yet far smoother, quicker reacting and more controlled over bumps.                                                                                                                                                                              

the front end on the xj was like an old man with erectile disfunction and needed something to stiffen it up a bit (or was that me? i forget now). but yeah it depends on what you have and what you want as to whether you go thicker or thinner.