Just to confirm how I chop and change my mind I've refitted the 15t sprocket to the GS again (from the stock 16t). After riding my Yamaha XJ600N (Diversion in UK, SECA in the US) for the last 4 months alongside my GS, I feel the need for that extra acceleration for the city commute (the Yamaha is for the weekend fun rides, the GS for all the routine stuff). I've also successfully rebuilt my front master cylinder using a rebuild kit - an absolute doddle to do!! :D
I'll be honest though - I think I did the brake unecessaarily as it has not significantly enhanced the feel of the front brake :dunno_white:. I think I need a new front brake pipe - that will probably firm things up. But hey...we gain experience through our mistakes, and I've got some valuable experience at no great financial cost.
If any of you need to rebuild your front brake master cylinder, then take it from me, don't hesitate because it is a very easy job to do - and the brake bleediing is a cinch if you take your time (there is a tread on this site which shows that i did not know exactly what I was doing at first!!).
Bassman