Triarm fork spring question (again)

[blueflag]

I'm trying to find out what sort of spec my forks were "upgraded" to before I got it (racebike).
I took the fork tops off (still with the air valve) found a long, thin walled spacer tube and washer beneath that. The spring appears not to be progressive, i.e. the windings don't get tighter at one end, although I have never seen a standard spring. The springs are etched with 8 and I assume that's the weight??
Any gurus out there know if it would be the correct weight for me (12.2 stone without leathers) The forks feel a little soft to me and the rebound damping seems a little lacking. They are filled with nice newish oil but I wonder if it would benefit from going a bit thicker.
Thanks guys!
Mike

[matt69]

If the springs are like the ones in my bike which have 85 etched on them and are .85kg, I expect they would be .80kg springs. I am 13 stone so yours might be about right with a little bit more tuning. Mine have been fully revalved so this would help as well and I do like a slightly soft front end.

My understanding of fork oil is that the viscosity is more related to rebound than to compression (someone correct me if I am wrong). What I would do would be to add 5mm more oil to the legs up to 10mm in total and see if that helps. This reduces the air gap in the forks and it is the air is the most compressible and is the initial part of the stroke. You could then try more preload with longer spacers (20mm pvc pipe works well, but use a pipe cutter to cut it as a unless you are very careful a hacksaw will give uneven lengths) if the extra oil doesn't work.

I always try the simplest things first.

Matt

[blueflag]

Thanks for the quick reply Matt,
Any suggestions for the air gap and oil weight to start me off?
Cheers
Mike

[matt69]

Thanks for the quick reply Matt,
Any suggestions for the air gap and oil weight to start me off?
Cheers
Mike

I'd start off with 10W oil and a 110mm airgap, forks fully compressed and with springs in.