ive got a set of 2012/3/4 forks (15mm) Servicing them is fine but id like to reduce the travel from 120 to 100 – do i need to just add spacers (which ive found in my spares box but not sure if they are from the reba) or does it need a new air assembly. i’ll just leave them if they do. Oh, is there any way of telling what year the forks are

Should be just spacers if they are dual air.

I’d like to go the other way, I have a set of 100mm rebas and wondering if they’ll go up to 120mm

That year sounds like solo air which means you need a new air shaft or the piston won’t make it to the little dimple to equalise the positive and negative air chambers.

Normally about 19 euros + postage from this place so a UK source might be cheaper: http://www.gabelprofi.de/index.php?lang=1&

I have a solo air 29er reba I was planning on doing the opposite it.

i suspect they are dual air in that there is a valve top and bottom – sorry to sound a numpty but correct me if im wrong…

Yep if there is valve top and bottom then they are dual air.

Have a search online for a guide its well documented how to do this, just need to take the air spring out and insert a spacer to reduce the travel. If you’ve serviced forks before then you’ll be fine.

@ ollybus, same thing have search online for the procedure, open your forks and see if there is a spacer on the air shaft you can remove to extend your forks.

Thanks @jairaj will do