Preload settings... yet again.

ye ye thats what I meant!! obviously it would take some mad witchcraft to adjust the springrate! i think the biggest thing in suspension set up is Damping. and if you havent got rebound and compression adjustability then it probably not worth worrying over!

[yorkie_chris]

Even if you have adjustability you're still pretty boned.

What you need is a big box of shims, a vice, a cylinder of nitrogen and the shim restackor software.

Or just buy one of these:

hmmm i'd probably go with the "buy" option, less risk of a spring shaped hole through my skull! (which by the way i would manage...somehow!)

[Mr Speirs]

Originally Posted by yorkie_chris

It does add force on the spring.

A linear spring shown as force vs compression will be a line like /
Preload changes the starting point, so the forks behavior will be more like
/
|

It doesn't increase the length, it increases the compressed length. The actual travel from topped out to full bump remains the same. (also exactly the same with no spring in there at all)

Terms used to describe suspension are a PITA!

Not sure I agree with you here.
Lets say a fork is on the bike and is weighted by the bike. This means the fork will be slightly under load. Now if you wind preload in all you are doing is pushing the spring down wards which in turn pushes down onto the bottom of the sanction and increasing the distance between the bottom yoke and the oil seals. Preload doesn't add any weight therefore force to the spring. It would only add force if the fork was already at full travel i.e. under no weight at all. Once it is loaded changing preload only increases and decreases the overall distance the fork is allowed to travel before bottoming out.
The same goes for the rear. You increase preload the collar pushes against the spring which in turn pushes against the bottom bit. As the spring is a linear thing aslong as there is no more weight added there can be no change in how much the spring is compressed between two completely different preload settings.

[yorkie_chris]

Ok, I was meaning in the unloaded condition. The other points still stand

Originally Posted by Mr Speirs

Also preload wouldnt affect ride or handling. It just stops the forks bottoming out.

I can certainly assure you that adjusting my preload did affect my ride/handling.

[Luckypants]

Originally Posted by madness

With progressive springs, surely increasing the preload on the spring effectively increases the rate at which they start to work? Hence the harshness I felt. Hitting small 'stutter' bumps while cranked over mid corner and feeling like the front wheel was about to let go was not what I was looking for when I set the sag!

I think Chris already answered that.

[Mr Speirs]

Originally Posted by madness

I can certainly assure you that adjusting my preload did affect my ride/handling.

I wouldn't have though it would have affected it much but I guess if you increased your preload you may have found the bike reluctant to turn in?

Originally Posted by Mr Speirs

I wouldn't have though it would have affected it much but I guess if you increased your preload you may have found the bike reluctant to turn in?

I had no problem with turning in, but the front end felt very 'skittish' over bumps. I'm wondering that with the increased preload whether I should reduce my tyre pressures back to 33/36 rather than the 35/38 I've been running for the last month or so.

[Mr Speirs]

Yeah I would reduce your tyre pressures if I were you. More pressure would give you less of a contact patch with the ground also when you tyres get hot your pressure increases even further.