Clunking noise under engine during hard rear braking?

[Zeus36]

Testing the bike: 2nd Gen, 1st gear, 20-30 miles per hour coming to a stop sign. When I try to lock up the rear brake, there is a clunking sound under the front of the engine. Seems to be more on the right side near the brake pedal. Like there is linkage moving. Is this the drive shaft moving? ABS? Suspension? Normal behavior?
Applying both front and rear brakes, I don't hear the noise.
Bike has a 240 rear tire kit and Soto Racing rearsets. Exhaust looks to be stock.

 

[one2dmax]

The ABS unit is under the seat nearer to the faux cover. It may let the noise propagate to a number of places.

 

[MaxMidnight]

Testing the bike: 2nd Gen, 1st gear, 20-30 miles per hour coming to a stop sign. When I try to lock up the rear brake, there is a clunking sound under the front of the engine. Seems to be more on the right side near the brake pedal. Like there is linkage moving. Is this the drive shaft moving? ABS? Suspension? Normal behavior?
Applying both front and rear brakes, I don't hear the noise.
Bike has a 240 rear tire kit and Soto Racing rearsets. Exhaust looks to be stock.

First question - why would you want to do this?
Second question - with ABS how do you expect to achieve it?

Sean has given the answer.

 

[Zeus36]

First question - why would you want to do this?
Second question - with ABS how do you expect to achieve it?

Sean has given the answer.

Response to your first question: Getting familiar with the motorcycle. I practice emergency stopping, counter steering, and low speed turning before I need to actually use these techniques.

Response to your second question: I've not had a motorcycle with ABS. My experience with automobile ABS is a pulsating brake at the footpedal. For this motorcycle, it sounds like there is loose mechanical linkage that is clunking under the engine. I would expect a foot brake pulse or a chatter at the rear wheel only since this is not a linked ABS system.

 

[Woody]

Apply more front brake.

 

[MaxMidnight]

Response to your first question: Getting familiar with the motorcycle. I practice emergency stopping, counter steering, and low speed turning before I need to actually use these techniques.

Response to your second question: I've not had a motorcycle with ABS. My experience with automobile ABS is a pulsating brake at the footpedal. For this motorcycle, it sounds like there is loose mechanical linkage that is clunking under the engine. I would expect a foot brake pulse or a chatter at the rear wheel only since this is not a linked ABS system.

Locking the rear brake to perform an emergency stop? Must look that that method up..........



............nope, nothing found.

 

[Zeus36]

I am not locking the rear brake for emergency stopping. That is the last thing you want to do!

My first post was about locking the rear brake for testing that allows you to become familiar with the point the wheel locks (which it does not in the Gen2) and will give you an idea of the limits of the motorcycle. You can use the rear brake for hook sliding. Locking up the rear brake and emergency stopping techinques are separate functions. Knowledge of your machine and its limits contribute to safer riding and the ability to calmly handle or avoid emergency situations. Emergency stops, quick stops, power slides, low-speed maneuvers, counter-steering, power-shifting and weight shifting all contribute to rider skill and confidence.

 

[MaxMidnight]

I am not locking the rear brake for emergency stopping. That is the last thing you want to do!

My first post was about locking the rear brake for testing that allows you to become familiar with the point the wheel locks (which it does not in the Gen2) and will give you an idea of the limits of the motorcycle. You can use the rear brake for hook sliding. Locking up the rear brake and emergency stopping techinques are separate functions. Knowledge of your machine and its limits contribute to safer riding and the ability to calmly handle or avoid emergency situations. Emergency stops, quick stops, power slides, low-speed maneuvers, counter-steering, power-shifting and weight shifting all contribute to rider skill and confidence.

Thank you for the lecture.
It would have been simpler if you had originally said you were trying to establish the lock-up point...but assuming you know it has ABS why bother?

 

[Zeus36]

Simpler if I had said I was testing the ABS.

 

[Jgas]

Great thread! Everyone should be able to lock both brakes. Brake slide. Countersteer under hard front braking. Get a dirt bike and practice! Then learn it all on the street a bit at a time. Might save you . It has me.

 

[Jgas]

Sorry. Another lecturer! My gen 1 does this under very hard braking. Its the centerstand. Tightened it a little fixed it. Wasnt loose just not tight.

 

[Jgas]

Uh. Just reread a bit more. Still applies. Abs is good not perfect. And it does occasionally fail. Early BMW abs killed folks. Its better now but i still trust in myself too.