RiderSite.com - Motorcycle Forums

Can anyone help me suss out the whole pre-load thing?

As far as I'm aware, we adjust the preload front and rear in order to get the correct sag. This corresponds to a certain ride height front and rear.

However, if you've wound on the equivalent of 50 kgf of preload then you need to overcome 50 kgf before the shock will move any further. Surely it's better to fit the correct spring rate in the first place such that zero preload is required, and then adjust the ride height to suit by dropping fork legs through stanchions and making suitable adjustment at the rear.

I only ask because I'm about to fit a white spring Mille shock to the Falco but the valve needs to be swapped for a recessed one, and the preload adjuster rings are jammed solid. I'm thinking of sending the whole unit off for a refurb with recessed valve fitment - is the rear spring rate correct for an 11stone rider (excluding riding kit)?

Same on the front really, fork oil hasn't been changed in at least 4 years so they're going off for a service and re-valve soon and wondered if the spring rate was correct.

Ta,
Mark

your weight - i think, would be fine, but i would talk to others just to be safe

yes, I would get it refurbed properly - depending who does it they will also advise you better than I can

Pre load doesn't change the spring rate (assuming we're not discussing progressive or multi-rate springs) - it just gives an offset

If you had a shock with a spring rate that gave you the 'correct' amount of sag with zero preload, it would feel very much like riding a hardtail; i.e. no compliance at all. The whole idea of matching sag, spring rate and preload is that it gives you a ride quality which should cater for 99% of all your riding, from smooth race-track quality tarmac (if you can find any) to the pothole-ridden reality that is Britain's roads today.

The only example I can think of where zero preload might be used is on something like a 125cc GP bike used solely on a racetrack. For anything that ventures onto a road, you need a compliant spring which will require preloading by a greater or lesser amount.

Fitting a spring to a shock with a rate whereby no preload is required to achieve 'correct' sag would mean that a large part of the shock (and spring) travel would be unused, and your arse would feel like it had been gang-raped by a herd of baboons.

Probably.

If you weigh 11 stone minus riding gear you'll probably find that the standard spring rates are already a tad firm (depending on your preferences, of course). I'd recommend getting the suspension refurbed and asking whoever you entrust with the work whether or not the supplied spring rates are suitable. If they're any good they should be able to advise.

and your arse would feel like it had been gang-raped by a herd of baboons.

And believe me, that doesn't feel good!

lots of baboons in berkshire it seems......


























































or has debz been playing with that butt plug again?

I'm with D-Rider, AFAIK the bounciness of the spring is a constant, so preload doesn't affect it's ability to soak up bumps.

Not that this helps anyone or that i know what i'm talking about but when i was having the 'Yellow spring Sachs' serviced Revs advised me that for my weight 14 1/2 st kitted i went up to the next spring, I've just got to work out with the aid of someone who know's how to slightly play with the suspension settings and explain in 'C Beebies' style how it works