So, having bought my new riser and putting in the weakest spring on the plunger button, I tested it out in the garden. The arrows were still going left but were moving closer to the target. The bow string has not been adjusted but the brace height was 20.5 cm straight out the tube - this is the lowest recommended brace height, but no vibration. My partner removed the arrow points which were 80 grams and replaced with 100's. I twisted the string and upped it to 21, vibration is back again. String off again and untwisted, no vibration. Started doing a few test shots and the arrows are now hitting in the centre of the target. I moved the clicker out slightly, my button is on the weakest setting and my groups although not really tight are okay so I've left it there.
First Portsmouth shot. Results and first time shooting with this bow, 493. My highest last year was 519, so not too bad. When I'm sloppy they go left when I overdraw they go right, so I think it's now a case of practising my form and getting used to the way the bow behaves. I find that I get the best results if I hold my bow arm straight out and pull with my right hand rather than push/pull action.
So basically, I've learnt that the Arrow Easton Chart for ACC's are more on the stiffer side (for me anyway) but as I get used to this weight and eventually max out the limbs, they should be okay and that increasing the brace height might have had something to do with the vibration on my old riser. This is an experiment for another day on my older 23" riser.
And, just another thing if you know what riser you really want don't, buy online! Bowsports charged me £195 in-store for this riser - on-line the bow is £150. I didn't have my bow on me so no setting up or anything, what a rip-off.
Sorry this has been a text heavy thread, hopefully my next post will be a bit more colourful.