[Downhill.Ben]

Hi guys.

First things first, this is my first post on the new forum, so hello to all. A couple of you Brits might recognise me from SDH. Came across here just because there seems to be even more knowledge here than there is on SDH and it seems like a good atmosphere.

Now for the question:..

How do i work out a spring rate of a Fox steel spring if the writing detailing the spring rate and storke as worn away? Is there any clever fancy way of doing it? It's a DHX5.0 on an '06 Stab Supreme frame if anyone knows the standard spring that comes equipt with?

I've had a look acorss tech files and folders online, but can't see anything specific.

Any help would be awsome. Thanks in advance

Ben

 

[blackspire]

Well there is always Hooke's law:

F = -kx

If you can measure the force you apply and how much you compress the spring (length wise) you can calculate k, which is the spring rate. To calculate what stroke the damper unit should have for the spring you have might be abit harder, but if you measure it and ask Fox they probably know. Have you tried emailing Kona? They should know this stuff

 

[jonKranked]

Well, unless you have some good equipment it would be hard to tell exactly.

Do you think your current spring is incorrect? If you're looking for a new one, steel springs are relatively cheap (you can find them for about $30USD if you know where to look, not sure what that is in pounds). Also, TFTuned has a spring rate calculator on their website so you can figure out what you'll need.

 

[ultraNoob]

To measure stroke length:
Measure the empty space between each complete coil of the spring. Add them up and you get the stroke length.

Measuring spring rate is a bit tricky but this is worth a shot and should be pretty fun to try. I'm not positive this is how it's done, but thinking back to HS physics, I remember doing something like this. Knowing that the spring rate is usually measured in lbs, one could assume that all the measurements are not metric. The following is done with the assumption that the spring rates are measured in lbs/linear inch.

Measuring spring rate:
Measure overall spring length. Place weight on the spring to compress it 0.5inch. Take that weight and multiply by 2. In theory, that should allow you to approximate your spring rate

 

[Downhill.Ben]

Yer, cheers guys. I think i'm going to have to use one of those methods. Was hoping there was some quicker way to do it.

Not to worry. Well, the sag I'm running is about 25%, so ideally I'd like another 5-10%. I've used Mojo's and Tf's spring calcs, and they've given me a desired spring rate. I don't want to fork out on a new spring if I'm already running the reccomended.

Thanks for the help boys

Ben