Shock Rebuilding/valving/spring Rates Etc.

[Omurru]

Alot of the blokes I work with ride bikes and rebulding/revalving shocks seems to be a standard every day thing for them, they continously have shocks at work that their rebuilding and it doesn't seem all that hard, how come it seems to be almost black magic when it comes to doing it for cars? I don't have a huge understanding of it all yet and neither do some of them, they just say yeh we get the specs for valving/spring rates for our weight and bike of the internet and just do it.....

Now in trying to understand how all this works I am presuming there has to be some sort of relationship between spring rates and valving? I have always wondered when you buy these cheap chinese coilovers and they offer multiple spring rates for the same shock how well does that work?

[_Ryan_]

koni's can be done in your shed eaily from what I know, Bilsteins require gas, so not as cheap/easy to do.

Most (push)bike forks are like a Koni, oil only, or with pressurised air provided by a hand pump.

[Omurru]

I have access to pretty much everything I could ever need at work engineering wise. Nitrogen charging isn't an issue.

[_Ryan_]

it sounds like you are in a position to give it a shot, grab a cheap set of bilsteins etc in need of a rebuild to play with, and go from there IMO. Do some reading, learn from those around you etc. Assuming you have a shock dyno?

[CoZZm0]

Alot of the blokes I work with ride bikes and rebulding/revalving shocks seems to be a standard every day thing for them, they continously have shocks at work that their rebuilding and it doesn't seem all that hard, how come it seems to be almost black magic when it comes to doing it for cars? I don't have a huge understanding of it all yet and neither do some of them, they just say yeh we get the specs for valving/spring rates for our weight and bike of the internet and just do it.....

Now in trying to understand how all this works I am presuming there has to be some sort of relationship between spring rates and valving? I have always wondered when you buy these cheap chinese coilovers and they offer multiple spring rates for the same shock how well does that work?

Shocks are there to control the springs. If you have a stiffer spring, you need more damping to control it. That's my basic understanding of it all. I have found this pretty simple, but helpful detail on some 'home style' rebuild on a Bilstein monotube shock:

http://www.honda-tech.com/showthread.php?t=2415915

I'm trying to reserach and learn as much as i can about it as i really want to increase my knowledge of it all, but as you say, it seems to be a bit of a black art and sometimes the specialist tools required can make things harder.

I also found seraching on youtube for shock rebuild videos came in very handy for a wide variety of different types of shocks. One person on youtube has over 700 videos of just shock rebuilds, mainly for ohlins motorbike shocks.

[odessy]

Digging up an old one. Anyone out their who has rebuilt some Bilsteins? I have seen a DUI thread and it doesn't seem all to difficult, only problem being regassing them which I have a found a bike shop that would do it (I think).

I have an old set hear I picked up for cheap that I was going to muck around with, anyone want to give me some tips?

[odessy]

After more searching and watching of videos this seems pretty easy. Only question is how do the pressurise/depressurise the nitrogen as there is no valve on the bottom?

[CoZZm0]

If you see the link in my post above you'll see you need to drill a hole in the base to let the charge out, and install a schraeder valve to be able to refill it (if you don't have the bilstein specialty tools, which of course we don't).