The 05/06 speedmasters with the 865 and cams optimized for low end torque develop thier max torque at a lower RPM than any of the other twins including 04 and previous speedys. Whether that goes any length to makes them more forgiving with more teeth i don't know. But what i CAN say is that i found that with the 17 the bike seems to accellerate faster. Yes, i know what you're thinking. But look at it this way....if the torque is enough so that it will wind to redline w/o taking any longer with a 17 than the stock 16, then you would be accellerating quicker because at redline you're at a higher speed. So technically the bike will accellerate quicker IF the bike is capable of pulling to redline as fast with a 17 as with a 16. My feeling is that it does, at least thru the first maybe 3 gears. after that it seems about the same. I realize i'll get flamed for this, but contrary to what many of you will be thinking when you read this i'm not stupid or naive and i do notice the bike pulls just as hard. Look at it this way.....if triumph is putting an 18 on them now wouldn't you think theres a reason? I suggest they realized AFTER they released the 05's that the new engine's increased torque didn't need a 16 to deliver max accelleration. After all, there IS an ideal sprocket size for every bike, and it would be naive to assume all manufacturers get it right every time. I could be wrong about this because my bike is modded and has considerably more grunt than it did stock, but in any case these are my findings.
I'll be calling the dealer to see if that free sprocket is available for me because i'd now like to try an 18. I have a feeling the 18 might just be one tooth further than it can handle w/o starting to struggle a bit, but it may be a worthy trade-off. And if i can try it free, WTF.
