got this mod done a week ago. replaced my 30 tooth stock pulley with a 31 tooth stryker pulley. sadly, i had to take my bike to a shop (first time in 7 years) to do it because my pulley nut had seized and would not come off with conventional tools. i purchased a 30" breaker bar and was bending it well past the 100 ft/lbs of torque that should be used to tighten the nut. purchased a 150 ft/lb impact wrench that did nothing so i took that back. the shop had to use air tools to get it off. so to all of you that had no trouble with this, i hate you all.
i've only got a few days testing so far but might as well post my observations. my main concern before doing this was that i would lose some acceleration in the lower gears. up to 3rd gear i can't tell any difference between my stock pulley and the stryker pully. between 3rd and 4th gear, it does feel a little bit longer in each gear but i really can't tell any loss in acceleration and i am HEAVY on the throttle in the city. on the highway i'm changing into 5th gear when the needle hits 60mph. it does seem to accelerate a bit more smoothly in the high gear and i guess there is some decrease in vibration due to slightly lower RPMs, but it is slight.
i tested the accuracy of the speedo with a free GPS speedo app on my phone. at 45mph on the needle the app reads 41-42mph. at 75mph on the needle the app reads 70mph. i'm running a 180/70r16 rear tire versus the stock 170/70-16. most people claim about a 10% difference between noted speed on any recent production cruiser stock setup versus actual speed given by either radars or GPS apps. i've been running a 180 tire pretty much the entire time i've had my bike and i've always noticed about half of that difference when passing road-side speed guns. never did any actual testing like i did now, but based on this i can't say that the stryker 31 tooth pulley gives me any more noticeable accuracy in speedo readings versus the stock pulley. if it does, it's a small percentage.
overall, i'm glad i've got the 31 tooth stryker pully on here. not a big difference, but it somehow makes the engine feel a little bigger and gives the perception of a little more torque in the lower gears even if it is in my head. and any decrease in highway speed vibration is appreciated even if it is minimal.