This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

Serious Brake fade

C

Crispin

Joined Mar 2008
538 Posts | 4+
The Wirral, UK
Guys, nearly wiped myself out at the weekend. Was building up speed round a little road circuit near me, braking later/harder, getting the tires up to temperature etc. Next mini-roundabout & the front break leaver was suddenly crushing my fingers on the handle bar, and I'd lost a lot of front break. I managed to save it somehow, but was only shear luck.

Anyone any ideas on what might be the cause & what I may be able to do do resolve? I've lost all confidence in the breaking.... :shock:

Crispin
 
Hi all, if anyone has any ideas as to what may cause sudden loss of break pressure after bringing everything up to temperature I'd really appreciate it. Don't feel I can take out again for any serious riding until I know I have resolved the issue.

BTW, my brake fluid spec is "Race Tech" dot 5.1.

I will try bleeding/renewing the fluid in any case.

Thanks

Crispin
 
Last time that happened to me it was because I bent the front rotor clipping a rock. Brakes pumped up fine when stopped, went away as soon as you started rolling.
 
Thanks Berger, somebody in work mentioned boiling the brake fluid, causing an air lock & then brake loss, which he did (dot 4), on his bicycle whilst mountain biking... anyone heard of this on supermotos?

Crispin
 
You didn't get into a tankslapper right before this happened did you? That will push the pistons back in the calipers, and you'll have no braking power until you pump the lever a few times. I've experienced this in my roadracing days.

I had a similar thing off road not long ago. The front just seemed to deflect hard off a rock. I grabbed the lever a few seconds later, and there was no pressure at all. I pumped it twice and everything was back to normal.

Overheating is a more likely culprit. I've only experienced brake fade though, not a dramatic drop off.
 
Hi Garrison, nope no tank slapper, just hard use of brakes until.... no brakes all of a sudden, very scary 8O
 
Crispin said:
Thanks Berger, somebody in work mentioned boiling the brake fluid, causing an air lock & then brake loss, which he did (dot 4), on his bicycle whilst mountain biking... anyone heard of this on supermotos?

Crispin
Click to expand...
How old is the brake fluid?
A friend of mine lost the front brake without any warning due to old brake fluid. Bike was a FS650 -06 with Motul RBF600 in the can.


/Nick
 
Hi Nick, brake fluid is about a year & a bit old... I read the owners manual, and it says you should change the fluid at least once per year, so gonna drain & renew entire contents.

Cheers

Crispin
 
Crispin said:
just hard use of brakes until.... no brakes all of a sudden
Click to expand...
What did you expect would happen?

That'll happen on any braking system if it can't disspate heat at least as fast as you're generating it.

Are you using a standard disc/caliper? Maybe you want to consider a bigger disc with a bigger surface area from which heat can be lost. If you have any sort of cover over the disc, remove it to allow air to get to the disc.

Brake fluid is hydroscopic - it absorbs water from the atmosphere. The water lowers the boiling point so change the fluid regularly.

Heat generated rises with the square of the speed. Stopping from 20mph generates 4 times the heat that stopping from 10mph does. Stopping from 60mph generates 9 x the amount of heat generated by stopping from 20 mph. Try riding a little slower or go and do a track day.

Riding on the road so fast that you get brake fade does a whole power of good to the public image of biking!

Greg
 
I had the same with my KTM 950 Super Enduro after chasing a KTM990 SM-R on the tarmac 4 years ago.

I had too much fun with late braking and fast cornering untill about 80% braking power disappeared suddenly.
Luckily I was on a dirtbike as I flew straight out the corner into a cornfield. (Still have scars on my stomach where the barbed wire cut through all my protective gear)

What was I thinking? A 400lbs/100hp dirtbike with just single 280mm brakedisk in front.
That is a sure way to get the brakefluid boiling after 15 minutes of intense use.

My friends say I have to drive faster for more air coolant. :roll:
 
GregUK said:
Crispin said:
just hard use of brakes until.... no brakes all of a sudden
Click to expand...
What did you expect would happen?

Riding on the road so fast that you get brake fade does a whole power of good to the public image of biking!

Greg
Click to expand...

I fully expect the brakes to work Greg.

It was about a 10 - 15 minute session when this happened, so if a Supermoto bike can last races without running off in a straight line & killing the rider, I sort of expected a 10 - 15 minute session to end without death or permanent disability due to the brakes failing.

This occurred on a disused industrial estate near me, with a "road" circuit comprising of a few mini roundabouts, couple of straights & a few corners. I hardly ever see anyone there, let alone any other vehicles, so I'd say the public image remains intact. I do, however, admire your conscientious attitude :holy:

Mosseltj, thanks or the account, sounds painful :shock:

Crispin
 
hello,

1. changing brake fluid once a year sounds ridiculusly for racing at least.
change it using high quality fluid ( i use denicol 5.1) AND DO IT WHEN THE COLOR OF THE FLUID BEGINS TO GO DARKER. this should be as often as 1 race.

2. i am sure your bike has a beringer disc brake the one with no holes.
in every supermoto bike with brake fade i came across the common factor was this particular disc brake.
when you change it go with MOTOMASTER OR BRAKING.

3. I NEVER HAD A BRAKE FADE WITH MY BIKE FS650 2008 , EVEN IN THE TIGHTEST TRACK WITH HUGE AMOUNT OF BRAKE USE EITHER IN THE FASTEST STRAIGHT FOLLOWED BY A 180 DEGREE TIGHT CORNER.

this means that surely something is wrong here!
 
oyk said:
hello,

1. changing brake fluid once a year sounds ridiculusly for racing at least.
change it using high quality fluid ( i use denicol 5.1) AND DO IT WHEN THE COLOR OF THE FLUID BEGINS TO GO DARKER. this should be as often as 1 race.

2. i am sure your bike has a beringer disc brake the one with no holes.
in every supermoto bike with brake fade i came across the common factor was this particular disc brake.
when you change it go with MOTOMASTER OR BRAKING.

3. I NEVER HAD A BRAKE FADE WITH MY BIKE FS650 2008 , EVEN IN THE TIGHTEST TRACK WITH HUGE AMOUNT OF BRAKE USE EITHER IN THE FASTEST STRAIGHT FOLLOWED BY A 180 DEGREE TIGHT CORNER.

this means that surely something is wrong here!
Click to expand...
Since Crispin used dot 5.1 fluid this post might not be worth anything... The RBF600 used in my friends -06 did not change color prior to the brake failiur and the bike was equiped with a Beringer brake disc.


regards

/Nick
 
Well, I'm fairly confident I've resolved the issue with the brakes. I've flushed fresh brake fluid through the front system using reverse feed through the slave cylinder. I used a syringe, pushing really slowly, and tapped the calipers & brake line while watching for air bubbles in the master cylinder. I took fluid out of the master cylinder using a liquid soap dispenser into an aerosol lid...(Heath Robinson eat your heart out).

Then locked off bleed nipple, then bled the brakes by slowly pumping the lever to build pressure, hold lever in, release bleed nipple & nip up, 3 - 4 times then filled reservoir to brim, put cap & screws in, tightened up, caught the excess oil, cleaned up & hey presto, lever feeling solid again.

Just gonna do the same with rear tomorrow night & jobs a gooden! :cheers:

Thanks for the advice chaps

Next a test run round my industrial estate at the weekend to build some confidence again, & I should be ready to go.

Gonna try & sort a van soonest (got green light from the better half so just a case of finding a part-x), so I can make it to Trax for the supermoto evenings. Won't be able to do the 31st as I'm away, but will be looking into future dates to attend after that.

Cheers

Crispin
 
Well well well..... took the Berg into a local garage & he's identified the problem!!

After all that messing about with the hydraulic side, it was the fecking disc!

Basically, the disc is crap, and has warped considerably resulting in a dish shaped disc. When this gets hot, it gets worse, hence the sudden fade when everythings hot! Feck me I'm glad that's sorted!! :bounce3:

Now then Berg Brothers, what would be one of the best discs I could get?, coz I'm going racing this year & want a bloody good set of brakes! 8O

I used to have a set of floating solid hoops sort of thing, which were amazing from what I can recall, any1 any ideas?

Cheers

Crispin
 
If you can find one of the berringer setups, disk and caliper, they work amazingly better than the stock setup. Mine are KTM, but are just a different color so you can look for either.
Mike
 
what you need is beringer bro 12 master cyl beringer disc iron outer !! and 6pot beringer caliper !!! give paul or brian at corsa italiano a ring 01932252255 there the uk importers tell them mark told you to ring them ! they both race an know what there talking about !
 
crispin heres a pic of my race bike from last year

003-3.jpg
005-3.jpg
 

Similar threads

Taffy
New - improved carb needle 2004-2008
Replies
3
Views
2K
FlyingZebra
FlyingZebra
K
New Guy to the place - and a ride report on my new FE 450
Replies
9
Views
2K
Taffy
Taffy
D
Dale E O's 2009 Idaho City 100 ride report
Replies
13
Views
3K
kzoo
K
canaberg
Chile Bites Berg (or Fryguy Finds a Rock)
Replies
5
Views
2K
DaleEO
D
D
Sparks Kokusan stator rewind, DC conversion,wiring upgrade
Replies
5
Views
6K
DaleEO
D

Register CTA

Register on Husaberg Forum! This sidebar will go away, and you will see fewer ads.

Recent Discussions