Another question about rear spring preload.
 

I have a k5 pointy and weigh 9 1/2 stone (scrawny git). I have always thought the ride was a bit bumpy compared to my divvy. Would slackening off the preload using the C spanner give me a softer ride? I assume the softest setting is for girls and scrawny gits and the stiffest setting is for fat *******s??!! or pillion riding or with luggage, or is this nonsense?

Not exactly.

Whatever you do with the spring preload, it's still the same spring under the same load, so given the same bump will compress a similar amount, however setting the spring preload at a different spot will mean that the starting and finishing points in the suspension's travel when it is deflected by said bump will be either higher up - increased preload, or further down - reduced preload.

It's an adjuster that allows you set to set the range in which the suspension will move - which will be a similar amount irrespective of setting* - taking account of the load that initially compresses it - ie: you/your pillion/your sandwiches/etc etc.

Note increasing preload doesn't make the suspension harder, it simply raises the position of the suspension under any given load. In fact if anything on a modern bike fitted with rising rate suspension, like an SV, increasing the preload ever so slightly reduces the spring rate as the linkage will be in a slightly lower part of the rate curve.

*Excepting if the suspension runs out of travel of course - there's only a finite amount.

The other thign you'll find is that if you think I'll take all the preload off and it'll be softer" (at the rear), then because of the linkage the damping ends up harder than it was - so instead of a stiff spring booting you out of the seat, stiff damping does the same. As there is only preload adjustment on these things, it is always a compromise. I've not ridden a pointy but I assume the shock is the same as the old ones - I weigh the same as you and used 4/7 or 5/7 on the back.

Somethigin else - if the front is soft (e.g. rubbish stock springs) it'll make the back feel harder.