what should i do i have a 525 chain on my 29 at the mo has lots of life left yet, but i have 520&sprockets from gf goes it make much differents with power and wait should i cut the the 525 off

if you like burning your money put the new one on .
i would wait till the one on the bike needs changed then change it . i look after my pennies

Considered this myself recently, but apparently there's not a lot of difference performance-wise, at least not for a road bike.

520 is lighter

yep lighter...less drag
stimpy

ok nice one cut or not to cut,try and grind the link thing off maybe

You'll not notice it though..

Just wait til you need to change the gear or you are wasting money