Could I have opinions please on wether to get my rear shock rebuilt or go for aftermarket one such as nitron or maybe a hagon bikes an nc30

Cheers

this is discussed many times, it all comes down to the budget and what you want for or from your bike.

and more importantly what you use the bike for.

Don't mind paying £350 or so if there was a noticeable improvement over a standard rebuilt shock bike use would be the occasional ride out and trackdays

if you got the £350 go for a aftermarket then nitron maxton etc, other wise a later model shock (£40ish) and a refurb for £100ish

There's a Maxton one on Ebay, or was. I considered this and Spanky's Ohlins and went for the latter.
My thoughts being that Spanky's Ohlins had been rebuilt and had the correct spring. Rebuild the std shock and from what I've read and what I know from other bikes they're soft, so ideally you'd go for a better spring. So you're into pobably £200. With the Ohlins when I sell the bike I'll sell it as std and the Ohlins seperate, it's always going to be worth what i paid for it. And you have a top quality shock.
See my post re Maxton or Ohlins. I've yet to receive the Ohlins but I have them on two of my other bikes and the quality is top draw stuff!

Yer i woudl go for an aftermarket shock if you have £350 to spend. Try and get a second hand one for £200 and get a fork uprate kit with the rest. I have used a nitron track shock (non remote res type) and found it to be very very good. I now use a maxton, and if feels lovely

Thanks guys i'l prob go for the nitron one it's bit cheaper than the maxton I've brought the up rate front fork kit from rick o and I know he does the shocks to, also going to be getting new hub from him for rear wheel conversion which leads me to the next question, is the nitron shock the same length as standard as I understand it's best to redrill dog bones to increase ride height on 17 inch wheel and wondered if shock was longer wether it would cancel the need to do this

All imput much appreciated

The nitron will have ride height adjustment so not a problem, you can have it as heigh or low as you like (within reason)