How to prevent boiling out your rear brake....

[andy york]

I have never over heated the front brakes on my LeMans. i have run out of brake on the rear.

I am a person that likes braking. I also like a little bit of trail braking but even that can over heat

the rear. 

And like other things, once you reach the point of over heating, you have to go so far in the "other direction"

to cool them down again.I would really like to ride the road you speak of    

Like you said, bigger caliper- more fluid-more pad area = more resistance to overheating.

a little air scoop wouldn't hurt either   LOL

 

[docc]

a little air scoop wouldn't hurt either   LOL

What about removing the plastic cover over the rear pads? The space faces forward . . .

[jchayes]

What brake fluid are you using? Brake fluid boils 'cause it's being overheated (duh) but different fluids have different boiling points. Auto Zone Dot 3 saturated with water will boil at less than 300 degrees.

 

Might wanna switch to new Wilwood or Motul RBF. Both boil at over 650 degrees.

 

Drain. Flush. Refill. Ride.

[JBBenson]

My rear brake (with new pads and freshly bled) isn't very effective, I need to really push down to feel anything.

 

I suppose this keeps me from locking it up. I don't think it is capable of locking up the rear wheel in any case. Is everyone else's rear brake the same?

[docc]

My rear brake (with new pads and freshly bled) isn't very effective, I need to really push down to feel anything.

 

I suppose this keeps me from locking it up. I don't think it is capable of locking up the rear wheel in any case. Is everyone else's rear brake the same?

Did you bleed the brake in the bracket or take it off and turn the nipple to the top?

 

Also, did you clean the pistons and equalize their movement?

 

Finally, there is a bedding procedure to transfer fresh brake pad resin evenly to the surface of the rotor.

[JBBenson]

 

My rear brake (with new pads and freshly bled) isn't very effective, I need to really push down to feel anything.

I suppose this keeps me from locking it up. I don't think it is capable of locking up the rear wheel in any case. Is everyone else's rear brake the same?

 

Did you bleed the brake in the bracket or take it off and turn the nipple to the top?

 

Also, did you clean the pistons and equalize their movement?

 

Finally, there is a bedding procedure to transfer fresh brake pad resin evenly to the surface of the rotor.

Not sure if I bled it upside down. It was a while ago. It's due again.

[Antiquar]

My rear caliper can lock the rear surprisingly easily with fresh pads and a fresh (upside down) bleed. 

[GuzziMoto]

My rear caliper can lock the rear surprisingly easily with fresh pads and a fresh (upside down) bleed. 

Same here, but neither the wife or I use the rear brake for much other than a parking brake. The front brakes have more than enough power to stand the bike on its nose. It really comes down to rider preference. They did not design the V11 for heavy rear brake use. It is much like every other sport bike out there, the rear brake is not overly robust. For most people that is not a problem. But the design of the rear brake can lead to issues for some as it does require more involved maintenance due to the mounting orientation.

I would not put a rear caliper that big on ANY of my bikes, but if you brake so much with the rear brake that you over heat the stock rear brake it may be a good idea for you. Or you could adjust the way you use your brakes.

[docc]

Riding style aside (granted, that is a significant issue), the two most common rear brake issues are old fluid and a sticking piston.

 

But there is another mechanical check:  The actuating rod that connects the foot lever to the master cylinder is prone to corrosion/ sticking and needs to be adjusted for a little play between the lever and the master cylinder.

 

Pull back the ribber boot and inspect/ clean/ adjust for play.

 

http://www.v11lemans.com/forums/index.php?showtopic=18158&p=192643

 

Part of the Wheels Off Maintenance Checklist.

[GuzziMoto]

I have seen where someone adjusted the height of their rear brake pedal and, without realizing it, prevented the master cylinder from returning fully to where the port was open to allow fluid in and out of the master. This caused the system to apply the brakes on its own, getting hotter and as it got hotter it applied more brakes because the pressure could not escape even though they were not knowingly applying the brakes . Eventually the brakes would fade, because they got so hot. It is easy to do the same thing just by laying your foot on top of the rear brake lever.

There are many things that can cause a brake system to fade. I have never had one fade because the caliper was not big enough. I have had brake fade because the disc was not big enough. Racing supermoto I had issue with fade twice. One was when I was racing a two stroke with a 270mm front disc (small by street standards but that is an oversize dirt bike disc), if I used only the front brake it would fade in four laps. If I used the back brake as well it would go 8 or 10 laps no issues, but I had to use the rear brake to take some of the load off the front. I think that was not only was the front brake on the small side but being a two stroke it lacked engine braking. The other issue was with a newer supermoto specific bike that had a bigger front brake and was a 4 stroke. The front brake lacked bite and would fade over a longer race. I switched to a better pad and the fade was gone, while the new pads offered amazing bite.

Neither of these stories has anything to do with the rear brake of a V11, but that is because we don't have any issues with the rear brake on the V11. And my Daytona has a very similar rear brake, goes even faster, and also has zero issues with the rear brake.

[Rox Lemans]

Just about anyone who does pretty heavy sport riding will agree that the tiny little rotor with that twin piston caliper on a heavier bike like a v11 is just too small. Might be adequate for some but for me personally? Hell no.

The day Scud is referring to I could of easily bit it if I kept hustling without a rear brake. I don't want to bust out the chalkboard and try tutoring guys here on proper corner braking but all in all I know it works for me.

 

Btw- Those Galfers are pretty sexy.. ;-)

[footgoose]

 ROX....  Now that I'm hyper aware of my use of the rear brake, I'd welcome your opinion on corner braking. Hell, if I knew it all, what do I need the forum for? It could be that all I need is a road like the one you and scud speak of, to reassess and develop my own style.

[jchayes]

Hey footgoose, Lee Parks has a good primer in his book "Total Control" as does Nick Ienatsch in "Sport Riding Techniques."

 

And ROX: when you bolted down that 4-piston caliper you also upgraded the master cylinder, right?

[Rox Lemans]

Master cylinder was definitely replaced. Twin piston too small.

[GuzziMoto]

Just about anyone who does pretty heavy sport riding will agree that the tiny little rotor with that twin piston caliper on a heavier bike like a v11 is just too small. Might be adequate for some but for me personally? Hell no.

The day Scud is referring to I could of easily bit it if I kept hustling without a rear brake. I don't want to bust out the chalkboard and try tutoring guys here on proper corner braking but all in all I know it works for me.

 

Btw- Those Galfers are pretty sexy.. ;-)

Uhhhh....No. That is not something that everyone who "does pretty heavy sport riding" would agree with. And there are bikes out there that are faster and/or heavier then a V11 with a similar sized rear brake. The issue is not the brake but the way it is being used. If you insist on using your rear brake that way, fine, replace it with an oversized caliper. But please keep in mind that their are guys on V11's that are faster than you who don't have an issue with the rear brake on the V11 (or the Daytona).

And please don't bust out the chalk board, I am sure you are happy with the way you ride, but I am also doing just fine without a giant rear brake caliper.