I now have over 1500 miles on my Grom and have done 3 performance mods that the really transformed the whole riding experience! First I changed out the front sprocket for one with 1 more tooth. This increases speed and sacrafices torque. Next I did the chimera intake swap eliminating the factory air filtration system and ducting and at the same time I changed out the factory exhaust with a MAD shorty system. I knew that if you just change the exhaust you end up with a lack of intake vacuum and that means no power in upper RPMs, and if you change just the intake you end up with the opposite. Now the bike pulls fast all the way past the red line so I need to learn my new shift points. The sprocket increased my speed by about 5-7 mph and made it much better even thou I weigh almost 200lbs it pulls much better! Now it sounds great and I think the rear looks much cleaner without that large factory muffler and bumper!