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Discussion Starter · #1 ·
02 with 12,000 on the clock fresh fluid all round, but the rear brake pedal still turns to fudge when the brake is used hard during fast mountain riding when two up with luggage . If you have had this problem and fixed it let me know how.

Regards
Esme
 

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Esmerelda said:
02 with 12,000 on the clock fresh fluid all round, but the rear brake pedal still turns to fudge when the brake is used hard during fast mountain riding when two up with luggage . If you have had this problem and fixed it let me know how.

Regards
Esme
Had it - Yes
Fixed it - No

I first experienced it a long time ago whilst riding in Norway, the explanation I were given was that the brake(s) were overheating thereby boiling the fluid.
The only solution I heard of is to refrain from using the brakes in "steep hill situations", to change down a gear and use the engine to slow you down with instead.
:ale:
 

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My advice is don't use your rear brake for braking on a steep hill, specially 2-up. Use it only to 'settle' the bike into a corner.

Under heavy braking as much as 90% of the 'weight/braking' is taken by the front (Keith Code - A Twist of the Wrist p60 - read it, it's worth the price of the book alone), and using the rear brake in these situations generates plenty of heat for very little stopping effect.

If you are using mostly rear brake this will be accentuated, so even though you think you are doing your pillion a favour because you feel rear brake is more 'pillion friendly', that friendliness ends when you overshoot the next bend.

Also, as the brake heats up, the gases escaping from the pads (I can find the source if you need it) act as a 'lubricant' between pad and disk rotor - the beginning of brake fade; so the rider/driver applies the ineffective brake harder, creating more heat = less braking effect. This repeats until the rider arrives at the scene of his accident.

How do you avoid this:
1 - use the front brake recognising that 90% of your braking effect is going to be from the front brake in loaded/extereme situations.
2 - regulate your speed by being in correct gear. Your engine won't mind going downhill at 7,000 rpm (on steep descents I usually select a gear where the bike holds it's speed at 6 to 7,000 rpm)
3 - brake hard, but in short spurts, and fully release the brake between braking to allow it to cool off. DO NOT trail your rear brake down a hill.
4 - If hustling along with a pillion downhill, brake at least as aggressively as you accelerate - if the pillion can cope with the acceleration they will cope with the braking (what was that about the feel of breasts in your back - get to know and like it)

There is school of thought that says that in any situation, if your overheat your brakes there is someting wrong with your technique - incorrect gear; incorrect braking technique; etc etc. I teach at that school :mrgreen:
 

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Agreed

all of the above
brake fluid boils when the heat transfer gets too much.

I didn't realise we had a rear brake on this bike.... :lol:
 

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Discussion Starter · #5 ·
Rear Brake Fade

David

Thanks for your thoughts on the matter. The big problem is that we like to ride
fast in twisty sections :wink: - the kind of fast that needs both brakes and the gears to scrub
off excess velocity (even the foot pegs do their best to assist mid corner) :oops: . We never
have this fading problem with our ZRX1200, or with the GTS1000, we don't even get it with our old Z1100R (though the frame does protest) :shock: . The FJR1300 is a big bus to slow up and I am not comfortable wondering if the rear brake will show up for work after the sixth tight corner in a 23 mile pass :twisted: (how I love the Pyrenees). I believe the problem is that single piston floating rear calliper and solid rear disk. I have never been a fan of Brembo brakes, well not the nasty mass production stuff (I am not talking about the mind numbingly expensive jewellery that adorns the more exotic motor cycles) :roll: .

The time has come to source a vented rear disk and a multi piston rear calliper and master cylinder to suit :shock: . This may seem like a lot of hassle but nothing compared to changing a riding style that has served me well for over thirty years!

I am off to the breakers to commence my research.

Regards
Esme.

PS. Thor, I thought you were going to stop by some time.
 

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Esmerelda,

"I am off to the breakers to commence my research."

Please keep us updated on your progress. I would be interested in improving the rear brake, too, since I almost always ride two up and like to use the rear binders along with the fronts.

dobias
 

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david1300 said:
My advice is don't use your rear brake for braking on a steep hill, specially 2-up. Use it only to 'settle' the bike into a corner.
...
Also, as the brake heats up, the gases escaping from the pads (I can find the source if you need it) act as a 'lubricant' between pad and disk rotor - the beginning of brake fade; so the rider/driver applies the ineffective brake harder, creating more heat = less braking effect. This repeats until the rider arrives at the scene of his accident.
...
There is school of thought that says that in any situation, if your overheat your brakes there is someting wrong with your technique - incorrect gear; incorrect braking technique; etc etc. I teach at that school :mrgreen:
Brake fade or boiling the fluids, or both? I was going slow down a 20 mile long, steep, twisty, mountainside gravel road as slow as I could, and I rode the back brake extensively to slow down at the switchbacks/keep speed from climbing on the downhill. Eventually found I had no back pressure. Panic pumps for 10-20 seconds or so restored pressure until it happened again a few minutes later, and so on until I eventually reached bottom. Not a happy feeling
 

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You don’t get brake fade if you have goodridge braded hoses and DOT 5
Brake fluid .
We run the bike with a trailer loaded with 300kg weight me and the wife side cases and top box and you need to use the back brake .
Never had brake fade

Have the same on the front

And if you don’t use the back brake or think you need not use it then your not ridding hard enough . :wink:
 

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Use a good dot4 dot5 absorbs moisture if you use dot5 ok but you need to change the fluid alot more even if it looks clean. Braided lines will help also. Have you check your pads the thinner they get the more heat that is transfered to the fluid .02c
 

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Re: Rear Brake Fade

Esmerelda said:
PS. Thor, I thought you were going to stop by some time.
Sorry,
Life caught up with me, this is the wrong time of the year to be in the Air Conditioning industry. :oops:

Still, we must meet up for a ride or :ale: at some stage

8)
 

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Europe's "DOT 5" vs. America's DOT 5

Shan FR,

I'm sure someone will correct me if I'm wrong, but as I understand it:
DOT 3, Dot 4 & Dot 5.1 are glycol based brake fluids.
DOT 5 is used by Harley Davidsons & by some racers.
Some people switch to DOT 5 because it doesn't damage paint.
DOT 5 is a silicone based brake fluid & unless great care is taken when switching from DOT 3 or DOT 4 the fluid will turn to gel.
Europe (& European bikes) doesn't recognize DOT 5, but instead refers to DOT 5.1 as just "DOT 5".

If you have switched to the silicone based DOT 5 successfully, I gather any change back to glycol based DOT 3, 4 or 5.1 would be significantly more troublesome because silicone is not easy to clean out. I've heard too many war stories about changes to DOT 5 causing severe problems such as gelling or gaskets swelling & disintegrating.

I assume you are a European. My question to you is are you using DOT 5 (silicone based) or DOT 5.1 (glycol based) brake fluid?

dobias
 

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If you are using any silicon based brake fluid watch out for pooling it can ruin your brake system.
 
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