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Old 02-17-2013, 08:40 AM   #61
doug s.
Beastly Adventurer
 
Joined: May 2011
Location: md
Oddometer: 1,243
Quote:
Originally Posted by doug s. View Post
nice! congrats!

but, i don't understand why the rpms would not be exactly the same if you didn't change gearing. if you were at 4700rpms at 74mph before, changing the engine displacement alone shouldn't affect that... you should still be at 4700rpms at 74mph...

doug s.
Quote:
Originally Posted by planemanx15 View Post
Even though the gearing is the same, the bigger engine works less to obtain that speed. At least that's my theory
regardless of how much the engine is working, (i suspect it is actually working more - making more hp at any given engine speed), it's still turning the same rpm's to get the wheels turning their rpm's... math is math...

now, because the engine is making more power at any given rpm, you could put a 41t sprocket on the rear (or a larger diameter tire) and lower your engine rpm's at any given mph, and the bike will still pull hard... you are already running 17-42; did i read that correctly?

doug s.
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