2011 103" Street Glide.

When idling/stopped in traffic, if I apply the front brake, the RPM's fall just a little and the bike runs rough.

When I release the front brake, while staying in a stopped position, the RPM's return to normal and the bike smooths out.

This does not happen when using the rear brake.

I mentioned this to some other riders and got the standard "They all do that."

Any idea what may cause this condition?

Thanks

 

Its normal. When you apply the brakes at idle the engine lope is transfered to the forks. And is no longer released to the ground by the wheel but through the bars.

 

Welcome to the life of a HD flh* bagger

They all (at least recently) do that.... I don't have the engineering to explain it properly, but it has to do with the engine/frame isolation, and using the front brake directs the vibration into the frame.

On the other hand, once you're rolling, the motor is smooth as silk.

The other choice is a frame mounted motor that is smooth at idle with the brakes on, but vibrates more at speed.

The things to take away are:
1) 'tis normal, don't worry
2) It is better to use just the rear brake (on any bike) at an intersections, with the motor in gear, and the clutch held in

 

Mine does it and I've often wondered how that could happen. I haven't wondered enough to investigate.

 

if your engine changes with the brake applied, it is just in your head, or you have a short in the front brake switch wiring somewhere going to the ignition..it could just be a vibration thing..locking the wheel to the forks/making it more ridged..

 

Why do you say this?

 

One reason is that your front rotors get very hot, and can cause deposits to be left from the pads. These deposits can build up and cause pulsating when applying the front brakes.

 

In my situation when idling at about 1k rpms, when I grab the front brake the rpms slow.

The reason it does this on my bike is that the front brake is the only brake control that engages the brake lights, the rear brake (pressure) switch hasn't worked since I got the bike. The current drain of all of my brake lights (extra rear brake lights too) puts a load on the charging system. At an idle that electrical load causes the rotor / stator recharge system to draw more current and that current draw slows the motor (at an idle) enough to sense a true change in rpms when the charging system is under load, at an idle.

 

Could be voltage...
When you apply the brakes the tail light comes on and a drop in voltage could make the bike idle down.
Maybe see what your voltage is, and if the battery/charging is ok.

 

At idle, there's vibration. Get off the bike (in neutral) and you can see the vibration and shaking through the front tire. When you lock the front brake at a stop, yes, the wheel no longer shakes in relation to the ground, but the vibration with the locked brake has no where to go other than the fork and into the bike.