So I have a felt redemption 3 with a DHX air currently installed.

It's leaking air at the moment so I want to swap it for a Float RP23. There's a 5mm difference in the eye to eye length.

Can I swap it or will it kill the shock/bike?

I figure this is a bit of a idiot question but I have to ask anyway as I don't want to be without a bike for two weeks whilst the DHX Air is repaired.

Any help comments would be appreciated

assume the RP23 is 5mm shorter, it'll certainly go on there…. how much difference it makes will depend a lot on actual shock sizes, including stroke lengths, and how much travel the bike has.

I guessed it would more complicated.

You're correct the rp23 is 5mm shorter.

How do I measure the stroke lengths?

The bike has about 165mm of rear travel and the bike the rp23 came off had similar?

My Enduro is supposed to have an 195mm shock but I've used 190mm and 200mm without any problem. All have had the same 50mm stroke length though.

As long as the i2i minus stroke is the same as the original shock it'll be fine, just a bit slacker.

If i2i minus stroke is less you'll need to make sure nothing fouls at full compression.

Stroke length is length of the air piston/shaft. The bronze coloured bit on a fox.

If this is the same, it'll be fine. If the stroke on the RP23 is longer, the bike will have more travel – hence what kenneththecurtain said.

Stroke length is the same on both so I figure it should be okay from what you've said which is good news.

Thanks for all your help

let the air out of the dhx and sit on the bike, if you have 5mm clearance on the back tyre when its bottomed out it will be fine, if less than 5mm your tyre will bottom out on the frame
or put the rp23 on with no air, sit on the bike and see if the tyre fouls the frame
either really
EDIT if it dos fit it will lower the bb slightly and slacken the head angle a bit