an idle observation...
Road Captain
Joined: Mar 2009
Posts: 715
Likes: 1
Actually it's your brakes that are stopping the tire's slight back-and-forth rotation on the axle that is amplifying that which is already there that you are simply redirecting. The motor is not a balanced motor as we all know. Everything on the bike is absorbing that vibration to a degree relative to it's mass and location. With the motor kicking fore-and-aft, the forks are acting like a whip so-to-speak albeit with far less dramatic oscillations. Those oscillations essentially "roll" the tire back-and-forth on the tarmac a minute amount and when you apply the front brake, you reduced the front wheel's ability to absorb that portion of the vibration mentioned earlier. Hence the shaking when the front brakes are applied. The rear swingarm ("fork" as Harley likes to call it) is on nearly the same plane as the energy and will not transmit those oscillations like the front forks which are on a plane nearly perpendicular to the movement. Hope that helps.
Cruiser
Joined: Nov 2007
Posts: 107
Likes: 0
From: hernando, mississippi
Actually it's your brakes that are stopping the tire's slight back-and-forth rotation on the axle that is amplifying that which is already there that you are simply redirecting. The motor is not a balanced motor as we all know. Everything on the bike is absorbing that vibration to a degree relative to it's mass and location. With the motor kicking fore-and-aft, the forks are acting like a whip so-to-speak albeit with far less dramatic oscillations. Those oscillations essentially "roll" the tire back-and-forth on the tarmac a minute amount and when you apply the front brake, you reduced the front wheel's ability to absorb that portion of the vibration mentioned earlier. Hence the shaking when the front brakes are applied. The rear swingarm ("fork" as Harley likes to call it) is on nearly the same plane as the energy and will not transmit those oscillations like the front forks which are on a plane nearly perpendicular to the movement. Hope that helps.
Road Master
Joined: Jul 2008
Posts: 1,092
Likes: 1
From: USA
Your kidding right? The 77'FXE i had would vibrate so bad the the even red locktite would not hold my tail light assy on. Was riding down the road one day,about 65mph and my whole assy. fell off from all the vibration that bike would make. I love it,that shows me how much power I have at my command while riding. The wife has a Heritage,I the RG,I would rather be on my than hers.JMHO
Advanced
Joined: Nov 2007
Posts: 56
Likes: 0
I have a theory on that causing the vibration change. When you press the brakes the brake lights come on which draws more current causing the alternator to work harder, which puts additional load on the engine. You can notice it in your car as well (just a slight decrease in rpm) when you turn on the head lights.
HD Forum Stories
The Best of Harley-Davidson for Lifelong Riders
7 Surprising Harley-Davidson Products that Are Not Motorcycles
Verdad Gallardo
8 Best Harley-Davidson Motorcycles Ever
Pouria Savadkouei
10 Worst Harley-Davidson Motorcycles Ever
Pouria Savadkouei
Killer Custom's Jail Break Is The Breakout That Refused to Blend In
Verdad Gallardo
Crazy Bunderbike Build Looks Amazing, But Is It Impossible to Ride?
Verdad Gallardo
Harley-Davidson Reveals Super Cool Cafe Racer Concept
Verdad Gallardo
Engraved Rebellion: Inside Bundnerbike's Glam Rock II
Verdad Gallardo
10 Motorcycles You Should Never Buy
Joe Kucinski
