Hi all,
I’m trying to fix an issue with an old Giant NRS rear shock. I have opened the air can which seems fine but the damper makes a strange grating noise as it extends and is very notchy. It also tops out with a bump when it rebounds. I suspect something is amiss in the damper or perhaps just not enough fluid?

Very hard to find info on this old shock – the best I could find was this: http://www.chetwynd.info/mtb/giant_nrs_shock_rebuild.htm

A couple of questions before I try and open the damper as the article suggests though.. I always thought rear shocks needed a nitrogen charge in the damper after the service but this article just leaves uncompressed air in the chamber by the look of it. Can this work? Its a long shot but any ideas on quantity or type of oil?

Cheers!

Interesting – for this rockshox monarch they use air: https://www.youtube.com/watch?v=iQQY1G9HRP4 But requires a special adapter for the shock pump.

Pretty sure the one on mine years ago needed nitrogen.

From what I remember, they are nitrogen charged (or so I was told when I worked in a Giant dealership for 8 years) & were never technically designed to be serviceable, as there wasn’t a service centre as such in the UK.
It’s going to a bit long in the tooth at best & quite likely to have score marks etc internally.
I’d save the effort & buy a replacement shock.

True it is very old – but then so is the whole bike so not worth throwing too much money at it. From what I have read charging with air is no major issue even for shocks which are supposed to use nitrogen. It may just be a case of finding the correct adapter for the pump?

Air is 80% nitrogen, I think the silky 3.75 inches of travel will be just fine with air!