What's the cheapest way of making my standard Marzo forks harder?
 

It seems my forks are giving me a hard time (can't brake as hard as I would like to before the whole bike starts vibrating, even if I'm using only 1 brake disc...).

Is there a cheap way to improve them for the use I make of them (hanging around Cadwell Park at desesperatly slow speeds...)? Even better if I can do it myself, I'm always happy to learn. Thicker oil? Washers to compress the springs?

You could add a small amount of oil to each leg (equal amounts) until you're happier.

or, add a shim/washer like you say.

I think both these ways will have different effects, although technically doing the same thing.

I think ;)

interesting answer my friend :)
But I could do with a bit more information (what kind of shim/washer, what oil thickness, etc)...

Otherwise I could just ride the bloody thing, but eventually I've got enough handicap with myself no to have a proper handling bike :D

thicker oil slows the compression damping down so it takes longer to get to bottom out but it still will bottom if the bump force is big/fast enough. a combination of thicker and more volume might help but it all depends how far out the springs are or whether its actually to much rebound packing the fork down ( the fork can't recover from one bump before it hits another so eventually it runs out of travel)

Preloading a spring with more washers won't make it harder, it'll increase the ride height but thats all. a spring moves a set amount for a set load, so its rated as say 10kg/mm it'll take 10kg to move it 1 mm and no matter how much you push it it down it'll always take the same 10kg to move that 1mm until the coils on the spring bind together. if you start with a higher ride height there is less chance you'll bottom it as the fork needs to move further. try and set sag up correctly and if possible swap the spring to a one which is correct.

you can put oil in them Tonio, what are you running now?

find out, then go for a thicker oil.

If you had std oil such as 7.5, then you could put 10 weight oil in.

otherwise, just put an extra 5cc's (centiletres) per leg to start with & see how they are. If necessary add another 5cc's per leg.

Giz, Tonio cant swap the springs on his marzocs, at least i dont think he can...

waiting for correction now:)

As alan says tonio.
Are they the early forks or the later ones ??

So if the bike vibrates when you brake are you sure the forks need to be stiffer? Could it be a warped disc? Or not enough rebound damping?

I'm running 9kg linear rate springs in mine with standard weight oil and standard oil amount, the difference was amazing for the price of a pair of springs.

call solent uk ltd and ask for dan, they are now the uk importer of Marzocchi, They are still learning and it takes ages for the springs to arrive but they can supply the later fork springs.
glyn