Today I got new a new chain and sprockets set fitted. I decided to spend a bit more this time on a better quality one (£50). It looks the part and you can tell the difference in quality just by looking at it. Anyway as you all know I have bad experiences in the past with garages who are incompetent, dishonest and greedy. Anyway took my bike to a garage half a mile up the road, the guy has been there since 1974 so that was a good start. Everything went fine he did the job and had my bike ready when he said he would. When I picked the bike up he spent some time with me giving me advice and it turns out I have been adjusting my chain wrong! He explained to me when I tighten it up before I check the slack of the chain I need to sit on the bike first. I didn't know that when I sit on the bike the chain tightens! So after all this time I know what I have been doing wrong.