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Rear air shock, needs pumping up?
I have been riding my first dualie for a few months now and decided I wanted to try out an air shock to compare against the coil I have now.
So I bought 2 second hand shocks (very cheap) to try out, problem is when I installed either of them as soon as I sat on the bike the shock didn't hold my weight at all and just compressed fully.
First I thought they were both faulty but that is very unlikely seeing as they came from two completely different people.
So do the shocks just need pumping up?
Or is it possible some how that my bike isn't compatible with air shocks as it came with a coil?
My bike is a 2003 Giant AC1, and the shocks are Fox Float & Manitou Split.
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Erm... yup... air shocks need air in em.
Put 150PSI in it and see how you go. Using a shock pump of course, nothing else is up to the delicate job.
Then sit on it and assess the sag, depending on what you plan to ride and how plush you want it 25-50% sag is a good ballpark isn't it?
Let all the air out before you remove from the frame of course.
Would you remove all the air before taking it off the frame? I can't see there's any need for that. In fact it might enable damage by allowing the shock to fully compress?
You'd take all the air out if you were opening it up for a service but not otherwise.
Erm... OK... perhaps not all, but I would have thought you'd have a hard time removing a shock with a lot of pressure pushing out on it's mounts.
Talking of shock service, a found a nice guide here:
http://www.mbr.co.uk/advice/workshop/MBR_News_Wo...
Might be time for some of this action for me soon.
With no rider on the bike the shock will be fully extended and very easy to remove. Best if the bike's in a workstand but not really necessary.
I'd suggest picking up the manufacturers manuals off the web, should be easy to find, they'll give you a table of pressures required for average weights and a good run through of how to set up the shock properly. They can all be subtly different with platform interactions etc. so it's best to get the instructions from the official source.
I had previously heard a sag of about 35% when you sit on the bike was average. As Matt says, see your manual for the correct travel or download it off the web. Hopefully you have a fairly new shock so it will be easy to find.
Also, it is not uncommon for your rear shock to lose a bit of air after a while. Just through use etc. More than likely, you will need to pump this up. Check the psi from time to time, about once a month would do. Oh, just like the rear shock, you should also be checking your front forks too.
Thanks to all of you for your help.
I pressed in the valves and only a tiny amount of air came out so they definitely need pumping!