I forked out £299 for a Wilbers rear shock with spring based on my all up weight in riding gear back in February since the OEM was approaching 15 years old & would have made a good "pogo stick"
. Any quality aftermarket rear shock has to be an improvement over a tired out OEM unit!
It has transformed the bike
Coincidentally I had planned to have the front forks refurbed this winter but as I amin the middle of some other work on the bike I have taken them over to "Revs Suspension" in Halesowen (who supplied the Wilbers shock) for overhaul which will entail New Springs, seals & correct grade of oil to suit my weight,riding style (mainly sedate these days!) & the spring manufacturers recommendations.
Talking to the owner of the business he tells me that in general the standard of OEM suspension hasnt improved since our Fazers were built, at least at our end of the market-ie non Ohlins. However he gets a lot of customers who have spent considerable money on Triumphs,BMWs etc who are disappointed with the OEM equipment & go to him to get their bikes handling the way they should.
IMO Money spent on upgrading/improving tired/worn out suspension can only improve matters...BUT if you dont know what you are doing leave it to those that do