Rear Brake Question....

[jstoof]

I believe my rear brake needs to be tightened but not sure how to do it...

 

[RJ2112]

2005 Yamaha FZ6STC FZ6 OEM Parts, 2005 Yamaha FZ6STC FZ6 OEM Motorcycle Parts - BikeBandit.com

Item #8 is the assembly that has the threaded adjuster to change the pedal height. You'll probably have to break loose the lock nut that prevents the shaft length from changing, then change the shaft length to put the pedal where you want it with relation to your booted foot.... then tighten the lock nut to hold the adjustment.

 

[jstoof]

So this should tighten the rear brake because as of right now it barely aids in stopping i can slam on the rear brake and it wont skid and will barely help stop

 

[RJ2112]

So this should tighten the rear brake because as of right now it barely aids in stopping i can slam on the rear brake and it wont skid and will barely help stop

You should be able to skid the rear tire by stomping on the pedal. If the pedal is too far 'down', you can't get enough force on it to do so. If the pads are shot, there's a lot more wrong than just the pedal height.

Get thee unto a formal training course........ the weight transfer ('dive') that occurs on a motorcycle, particularly one that has a short wheel base will almost completely 'unload' the back wheel. You can't use it to stop, if the wheel isn't touching the pavement.

The question I think you are asking, indicates there's a lot of room for learning....:thumbup:

Back brakes on a street bike are almost in the 'Hail Mary' class, for stopping the bike. Less than 20% of all the stopping power available comes from that wheel.

The vast majority comes from the front. That's why the rotors are so much bigger, and the calipers more advanced in design. When the front 'dives', that puts a LOT more weight on the front tire, which gives you a LOT more traction.

 

[jstoof]

You should be able to skid the rear tire by stomping on the pedal. If the pedal is too far 'down', you can't get enough force on it to do so. If the pads are shot, there's a lot more wrong than just the pedal height.

Get thee unto a formal training course........ the weight transfer ('dive') that occurs on a motorcycle, particularly one that has a short wheel base will almost completely 'unload' the back wheel. You can't use it to stop, if the wheel isn't touching the pavement.

The question I think you are asking, indicates there's a lot of room for learning....:thumbup:

Back brakes on a street bike are almost in the 'Hail Mary' class, for stopping the bike. Less than 20% of all the stopping power available comes from that wheel.

The vast majority comes from the front. That's why the rotors are so much bigger, and the calipers more advanced in design. When the front 'dives', that puts a LOT more weight on the front tire, which gives you a LOT more traction.

Yes i understand the physics and what not of it but i just think the rear brake still needs to be tightened some because if im applying just the rear brake you would think that it should at least stop the bike rather then just letting it coast... and i dont think the pads would be bad it only has about 2300 miles on it but i could be wrong

 

[Dennis in NH]

Check pads and then brake fluid and maybe there's air in the system (i.e., brakes need bleeding?)

And like RJ2112 said, check the pedal height. Also, just look at the brake pedal and ensure everything looks good and is working right. Again as RJ2112 said, you should be able to skid the rear tire.

Hopefully, your fronts are in good kick butt order because they will stop you pretty good if used right.

Dennis

 

[jstoof]

Haha in know the front brakes are good my first day riding it i learned what a stoppie was lol but ya ill go check the brakes and see if there is something else going on because i definitely cant get it to skid with just using the rear brake

 

[RJ2112]

Haha in know the front brakes are good my first day riding it i learned what a stoppie was lol but ya ill go check the brakes and see if there is something else going on because i definitely cant get it to skid with just using the rear brake

Look for any leaking fluid. Look at the brake fluid reservoir, and tell us what color the fluid is. Look at the rotor itself..... are there any deep scratches or heavy grooves cut in it? Feel the back side of it as well.

Could be that the lever is 'spongey' from trapped air, as well.

 

[jstoof]

I checked my brake fluid which was fine and the rotor was smooth all the way around

 

[RJ2112]

What happens when you rapidly 'pump' the rear brake? Does the pedal become more firm?

 

[jstoof]

What happens when you rapidly 'pump' the rear brake? Does the pedal become more firm?

It doesnt... when i was looking for an fz6 i test drove a different one and the rear brake was much better on that one so i know its something with mine and just not in my head i just cant figure out what it is

 

[RJ2112]

It doesnt... when i was looking for an fz6 i test drove a different one and the rear brake was much better on that one so i know its something with mine and just not in my head i just cant figure out what it is

So the pedal 1) travels through a 'normal' arc, and doesn't slow the wheel, or 2) it moves too easily through the arc and never gets any resistance?

 

[jstoof]

So the pedal 1) travels through a 'normal' arc, and doesn't slow the wheel, or 2) it moves too easily through the arc and never gets any resistance?

the pedal travels fine but just doesnt grab really until the very end which by then doesnt offer much braking resistance

 

[RJ2112]

the pedal travels fine but just doesnt grab really until the very end which by then doesnt offer much braking resistance

It would be easier to diagnose if we could establish how far the tip of the rear brake pedal is moving.

Hydraulic systems don't really have any way to be 'tightened up'.... they work by moving one piston, which then transfers the work done, to another piston somewhere else. The diameters of the pistons involved determines how far they move. If the two are equal, the distance traveled is equal.

Most master cylinders have a very small bore, with relation to the surface area of the pistons in the caliper. You move the master quite a distance compared to the 'slave'.

Because of that difference, the force you apply to the slave, is multiplied.

With your scenario, we don't know if the distance the lever is travelling is enough to move the master through it's full stroke. If it's not going far enough, you cannot generate the required force.

Two possibilities relating to the hydraulics of this:

1) seals in the master are compromised, so you cannot 'hold' the pressure you generate to operate the slave(s) to squeeze the rotor. If the fluid in the reservoir is clear without any brown color to it, and it's between the low and high marks..... odds are pretty good this isn't it. If the caliper were leaking, you'd see the fluid on the wheel, and rotor.

2) the lever is set too low, so you cannot depress it all the way through it's intended arc. (you should have the lever set, so it's right beneath the sole of your shoe, so it's going to start acting on the master as soon as you touch it.)

I'm not yet clear on if the above two have been addressed. Let's get that sorted out, then if we have to we can move on.

The non hydraulic possibility is that the pads are 'glazed'. If the pads weren't properly broken in, they could have lost a lot of their friction capability. When someone over uses the brake, it can get hot enough to almost form a ceramic coating on the face of the pad.

You can check that by popping the pads out of the caliper, and scuffing them up with sandpaper. Just remove the really shiny surface glaze, and they should return to normal function.