Pulsing brakes when sitting still. - Harley Davidson Forums: Harley Davidson Motorcycle Forum
 
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post #1 of 8 (permalink) Old 10-02-2012, 10:13 PM Thread Starter
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Pulsing brakes when sitting still.

I may be getting parinoid here but it seems the last 2k miles i have noticed magnified vibration while sitting still when i apply either brake. it is picking up the engine vibration more in the bars and floor boards. IS THIS NORMAL? it may have been there all along but i just seemed to notice it.
I may be nit picking since i found variious problems after the stealer did the 1k service. going to a different one for the 5k...
Any thoughts?
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post #2 of 8 (permalink) Old 10-02-2012, 10:18 PM
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The two Harley's I have owned do the same thing.

I am no physicist but I assume that is because you are taking the play out of the wheels and making another part of the bike rigid.


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post #3 of 8 (permalink) Old 10-02-2012, 10:21 PM
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If you release the brakes it should vibrate less. Not holding the brakes when you stop allows the bike to move with the idling engine, thus damping the vibration. Holding the brake stops this process. Sometimes you just got to hold the bakes and deal with the extra vibration.
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post #4 of 8 (permalink) Old 11-21-2012, 10:59 PM
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Ive have noticed that when you hit the brakes your amp gauge lowers and the tach drops a little when the alternator kicks in. Also, mine seems to vibrate alot more if you pull.up to a stop with just rear brakes.
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post #5 of 8 (permalink) Old 11-21-2012, 11:25 PM
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Holding the front brake lever so as to activate the front brake does transfer a lot of vibration into the handlebars; it is most noticeable when not moving. It is very pronounced on my 2009 Dyna.


Quote:
Originally Posted by ricksglide View Post
I may be getting parinoid here but it seems the last 2k miles i have noticed magnified vibration while sitting still when i apply either brake. it is picking up the engine vibration more in the bars and floor boards. IS THIS NORMAL? it may have been there all along but i just seemed to notice it.
I may be nit picking since i found variious problems after the stealer did the 1k service. going to a different one for the 5k...
Any thoughts?

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post #6 of 8 (permalink) Old 11-22-2012, 03:33 PM
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I noticed that if you watch the front tire when idling without holding the front brake you will see the tire "roll" slightly forward and back. The vibration you feel is minimal. When you then hold the brake, the front wheel stops moving and your teeth bang together because the vibration has to transfer somewhere.


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post #7 of 8 (permalink) Old 11-22-2012, 04:15 PM
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Energy from flywheel rotation is lost via the wheels when sitting still. It's transfered to the chassis, which bleeds it off into the wheels and into the rider. Proof of that is simply watching the handlebars shake.

Hold the brakes on, and the bike is forced to be stationary, and that little bit of energy that would have made the bike move a little bit, is now kept in the chassis, and forced to show up somewhere else.

That energy will translate, like electricity, to the easiest path: The rider on the bike.

Don't forget, your flywheels spin forward, (towards the front of the bike) and as each cylinder fires at 315* with a 405* gap in between.

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post #8 of 8 (permalink) Old 11-22-2012, 04:36 PM
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Quote:
Originally Posted by 2010hdultra View Post
Ive have noticed that when you hit the brakes your amp gauge lowers and the tach drops a little when the alternator kicks in. Also, mine seems to vibrate alot more if you pull.up to a stop with just rear brakes.
I changed to all led lights. The drop in amps no longer happens on mine. I never noticed a drop in rpm when I was holding the brakes.


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