My new front sprocket arrived yesterday...15 tooth [one less than standard]. I took the bike for a blast then changed the sprocket and went out for another blast to assess the difference. It was pouring down with rain so I only went for a quick 10 mile spin...but the difference was noticable. The bike is a lot more urgent when applying power, It seems to pull out of corners better and it goes through the gears quicker, surprisingly not affecting the top speed by much [although I wasn't going to push it too hard in the wind and rain]. All in all it was the most enjoyable ride that I have had on this bike...I got home grinning like a cheshire cat even though I was drenched! On a little country lane near where I live I had a great blast around some twisty bends...I can't wait to do it in the dry!
I am seriously considering going up a couple of teeth on the back sprocket as well now, because for me the acceleration is more important that top speed. Now this might just be my imagination because the bike felt so much sportier, but I swear it was handling better as well!! Impossible? Well because the new cog uses a link less I had to adjust the chain by almost an inch [it was a bit slack to start with] possibly this lengthening of the bikes wheelbase has improved it's handling a bit? I don't know, just guessing.
In short...for the sake of a £7 sprocket the bike is much improved.