I'm running 14/45 which I guess is pretty close to 15/48. Lots better than standard. Also fitted a speedo healer as the indicated speed without it was way over. As to top speed, I worked it out on a gear/speed calculator and its about 8mph lower. Natural cruising speed for these bikes is about 85 which is well in the comfort zone as regards revs. If you want to go faster just thrash the knacks of it.

Steve

I am currently running with a 46 tooth supersprox sprocket and it it does give slightly more punchy acceleration but is losing out slightly at top speed, I also have a renthal 42 tooth rear sprocket that I put on when going longer distances. I imagine the 48 tooth rear sprocket is good fun but it will limit top speed and make the bike more 'buzzy' at speed. The supersprox are much better quality though than the Renthal and appear to wear less.

did you re calibrate with the 46 sprocket?

Norton

If you change from stock setting you will need to recalabrate the speedo or else it will be out by how much depends on the sprocket size. As manicmic says the bigger the rear sprocket the faster you bike will get off the line but top speed will drop. Wheather or not you go to that top speed ever it will drop. Also this will therefore drop all your other gears down a little so if you feel for example no buzzing at 70mph but you do at 73mph when you chance the sprocket you will probably now get that buzzing at 70mph. Do you catch my driff.:smilies0943:

Depending on what type of riding you do depends on wheather you like it.

yes, all understood a while back I could get away without re calibrating which it appears I can't so sticking with 45 and probably steel not alloy as last alloy hasn't lasted too long compared with stock OEM steel one.

Thanks to all for your inputs, sorry if I got caught up in the possabilities, I guess I got lured by the faster pull away siren ;)

This small flash utility will tell you what speed you will get with various sprockets.

http://ranni.altervista.org/xtx/

Excellent link, thanks. It turns out that if a larger sprocket is added to the front you are going faster than indicated and also prematurely adding miles to the bike, if the larger is on the rear you are going slower than indicated and putting less miles on the bike whilst having more fun.

My question to you all, how often do you ride at full speed? against every day riding.

So you will loose a few k's at top speed, it does not worry me as I do not sit at top speed all day on my bike & might try it out once every few months for a few min's & then it's back to every day riding.

You might loose 8MPH by maths on top end, but in the real world on the flat the bike will find it easier to run to top end & you might only loose 4MPH, unless you are on a long down hill but on a flat my bike gets to 100MPH with no problem.

havent gone that fast yet kev. Dont know if i would dare or i might get MR:50: coming down behind me. At least half of my jounry at the moment is on motorway i know boring but has to be done. Normally just sit at 70mph but find she has enough get up and go anyway as she is alot lighter than my old Deauville which was around 245kg fully fueled but - me and other stuff.