Fitting front springs - Nth East.

Ok guys my springs arrived this week and armed with a haynes manual im going to have a go at fitting them myself, i've ordered a front headstock stand that should arrive Wednesday. So a few questions before i start, is the standard 94mm air gap ok with the 0.9 k-tech springs i ordered ?? . Can i use methylated spirits to clean out the fork tubes ?? and last of all will castrol synthetic 10w fork oil be ok for refilling ??

[NTECUK]

Wouldnt use meths.
WD 40 will get any stubbon bits out.Best not mis mineral oils with organic

Ok thanks, i'll pick some up at work in the morning.

[yorkie_chris]

Meths will be reet, it will evaporate.

Any thoughts on the air gap and choice of oil YC ??

[yorkie_chris]

Try the 10 and see what it's like, much heavier might be slow this time of year. 94 is too small IMO, try 125

[embee]

I've used Castrol Synthetic 10W and didn't like it. The Viscosity Index (VI) is relatively low (42cSt/VI=150) so it gets quite a lot thicker when cold, made the front feel wooden IMO, only got better after a decent run when it warmed up a bit.

I prefer Silkolene PRO RSF, it has a high VI so viscosity doesn't change as much with temperature. I'm about 12st and use 0.85 springs in my curvey, and use RSF 7.5W which has a viscosity (40degC) of about 37cSt/VI=322 according to the white table halfway down the page in the fork oil bible , which puts it in the same league as most 10W oils. It's at the "comfy" end of suitability for me I'd say.

For you with 0.9 springs I'd suggest RSF 10W, the 7.5W will be too light for those springs.

If you can't source the Silkolene PRO RSF (I get it from Opie oils but I get some discount with a club) try something in the same range with a reasonably high VI in the table, the author likes Red Line. I've seen the PRO RSF on ebay. Worth the effort to source some I'd suggest.

Thanks for the info guys, think Im going to stick with the castrol (already bought it) and gonna try Chris's suggestion of 125ml air gap, see how it goes, may buy the other oil if this doesn't work out. Will let you know how it goes. Thanks.