Spring rates for 2012 XCs

[ggalex]

With thanks to Clay for the following very useful info for baselining the suspension on the new 2012 XCs...

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Originally Posted by Clay

...I think you might be surprised how good these forks work with the odd set up I'm using. First get the springs correct. This is critical. Then back the clickers out all of the way and turn the pfp valve in one turn. I'm sure that Marzocchi did not intend to for the fork to be used this way but it really is working good for me and Zach, my son. I can not remember my front wheel running down a root in the last two national enduros. I think you guys should give this a try before you spend re-valve money.
Here is an approximate guide that I worked up on springs:
140 pounds stock front stock rear
160 pounds .44 5.4
180 pounds .46 5.6
200 pounds .48 5.8
220 pounds .50 6.0
240 pounds .52 6.2
260 pounds .54 6.4
The first number is the fork spring, second the shock spring.
Clay

[twowheels]

Originally Posted by ggalex

With thanks to Clay for the following very useful info for baselining the suspension on the new 2012 XCs...

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Looks about one to two rates too high, but that might just be me.

[Jakobi]

I thought the same thing..

I'm 175 nude and the stock .42 and 5.2 weren't far off. Its just the riding gear and sack of tools that push me over.

[STM Suspension]

I've been having this conversation with Jake...

The spring is an interesting thing and it has lots of roles; it has to hold the bike up in the right position- too high and the bike never compresses and the wheel has no ability to follow the hollows in the ground, too low and you're always in the progressive part of the air spring; it has to hold the bike up during weight transfer from acceleration and deceleration- when you brake hard and the front goes down too far and the gets nervous (our new AA Pro Enduro test rider had this comment about his new '12 300 with the 48 Zoc's, and he's 165 lbs) this is typically because of too soft fork spring- remember, damping is a velocity term- that means that it's only effecting stuff while the suspension is moving- if you're braking long enough that the front goes down and settles, it's spring, not clickers. And much more.

But also the spring pushes the wheel down on the ground. If the spring is too light, then when you hit something (like a rock), the wheel 'jumps' up out of the way. Or tries to. Then you have high suspension speeds. Damping is a velocity term, so you get a ton of high speed damping when you least need it. Sometimes, if you use a little more spring, ie a stiffer rate, (to a point), the suspension actually feels more plush- because now the spring is helping to do it's part- it's holding the wheel down a little more, giving the damping circuits a little time to catch up.

I'll be honest, this is seriously important. There's a lot, if not more, to valving and getting that right so it all compliments each other- everything has to do its part otherwise we're just trying to band-aid stuff- adding preload or adding compression damping trying to make up for a too light spring is just going to make the bike ride like crap. Really.

This is just scratching the surface of what really needs to be going on when you talk to your suspension person- they really need to be understanding all of this. A lot of people I talk to comment on how complicated suspension tuning is. I whole-heartedly agree- that's why after I started doing suspension work I went back to university and got a bachelor of science degree in mechanical engineering with an emphasis in vehicle dynamics. I think I have an ok grasp of what's going on but I learn new things every day, every day. So if you're having a hard time wrapping your head around it, that's ok, it really is that complicated.

[STM Suspension]

Oh, and those spring rates posted above are almost assuredly directly from Ohlins.

[Simmo737]

I reckon they are ohlins, 4.8 to 5.0 for 200lb rider weight no gear.
They are the same as Race tech for 200 lb for a bike the same weight enduro/desert including gear.

Can't agree more with stm. You use a spring that requires more than 5mm preload front or around 10 rear to get good sag setting and it will be harsher than the heavier spring with correct preload and correct sag. I proving in to myself again and again. Don't think for a moment that soft springs mean soft ride. You ask nine out of ten pro or fast amateur riders and they will like light valving( by their standard)/ heavy springs.