That is the nitrous kit that I use, and yes it is fun to be running WOT downhill and hit the trigger and feel the pull like you see in the movies, but the speedometer on my bike tells the true tail that Nitrous adds about 4mph.
I can add 7-8mph just by pedaling hard. My bike is geared high enough I can pedal at top gear along with WOT.
case in point: the added power from a surge of nitrous is less that what you can provide manually by pedaling. Not to mention the power from pedaling is available for longer and more convenient, plus it is safer.
Either way, the way to go faster, really, and this is pretty much the absolute list:
For the MOST out of your ENGINE safely and easily:
1. Port match and polish intake and exhaust
2. Upgraded Carburetor
3. Expansion Chamber a.k.a. Tuned Pipe
4. Best electrical components you can find (high performance plugwire and plug)
5. Boost Port the cylinder
6. Use Bel-Ray Si-7, or AMSOIL Saber (dirtbike racing 2-stroke synthetic oil) in LOW OCTANE fuel (it detonates more violently at the expense of smoothness)
For the Hardware: The idea is to have the bike set up so that you can achieve a desired speed without trying to force the engine to rev beyond what it is made for.
1. Use a 29inch wheel Cyclocross bike- as lightweight and sturdy as possible, made for racing
2. Use either a highspeed low tooth rear sprocket as low as 25-27 teeth OR a shifter kit from SBP OR a modified scooter CVT bolted to the frame (this one is hard to do but it is AMAZING)
3. Keep your tires at maximum running psi
For the rider:
1. weigh as little as possible.
2. ride in bicycle racing attire, to minimize wind resistance ( this includes a helmet for safety)
There you go. This is how to have a top speed bike, a lot of it also comes from luck of the draw on how your engine performs out of the box due to low manufacturing tolerances, few are F1 grade by sheer luck, most are just useable, some fight you every step of the way just to run.
and it is absolutely true that the more you demand from your engine the lower its life expectancy will be. That is the point of doing everything possible to achieve high speeds with lower RPM through gearing. More speed= more vibration... vibrations make EVERYTHING fall apart, even you, so remember that just like in professional racing after every run with a "high performance" motor, you must go through and check and retighten EVERYTHING, because everything is subjected to so much more force than a daily easy rider.
Have fun! and plan to work for every MPH you try to gain! You WILL burn through as much blood sweat and tears as you do fuel trying to get these to go faster, and lets not forget the investment side of the deal!
$1000 High quality 29inch cyclocross bike
$250 High quality SkyHawk engine from spookytooth
$100 for upgraded carburetor
$250 for Andyinchville's tuned pipe
$200 for SBP shifter kit
$100+ for labor on professional port and polish
$50+ for Electrical and Fuel/Oil accessories
$50+ for streamlined clothing and various expenses (parts etc.)
TOTAL for "superbike" ~ $2000
(...just buy a motorcycle on craigslist...)