Rear shock replacement

[jorgemartin]

Hello, I have a 150 mm rear coil shock that I would like to replace. I am not to able to find 150 mm or similar length shocks. Looks like most shocks these days come in 222 or 240 mms. I have also found a few in 190 mm. Do you think I might be able to replace the one I have (150 mm) with one of the longer ones? Why are there so many lengths? It is very confusing. Also, are coil shocks supposedly more reliable and durable than air shocks?

 

[rusty bearing]

Are we talking about a pure coil shock or a coil/air type such as the DHX4?
Fitting a longer shock would if even possible, completely alter the geometry and handling of your bike at the very least so not recommended. There are as many lengths of shock as designs call for.
The coil/air shocks like the DHX4 will take bigger hits than say an air shock like an RP3 so are mainly on serious downhill bikes. Any reasonable shock if serviced and maintained should prove pretty reliable, my Fox RP2/3 is as good as the day I fitted it. I do have it covered in a Lizardskin as well, helps keep the crap out.

 

[jorgemartin]

It is a coil shock. Problem is to find a replacement in this length: 150 mm.