Brake Boost

[Team RGM]

Looking for information on power brakes (some form of brake boost).
I've set pedal/cylinder ratios such that I'm near the limit of my foot movement but cannot lock wheels when tires are hot. Would like some more pressure. Has anyone have any ideas? If done, then parts list and pictures.

LCR/GSXR1000.

Rick Murray, Driver USA
manager@teamrgm.com

[Kickaha]

What size master cylinders are you using, what is the lever to m/c ratio and what pads are you using?

[steve-e]

^^ exactly the questions I was going to ask.

Barry Fleury used to run a servo system but you shouldn't need to with the equipment. Barry liked to experiment ( and a lot of his stuff worked)

[idris]

Barry's problem was that his ankle was knackered & didn't have full movement, which is why he used a servo.

[steve-e]

that makes sense

[Team RGM]

Thanks guys,
I will take measurements this weekend and get back to you.
Bu the way, running PFC PF1 compound all around and 50/50 front rear bias

[oldbelly]

We used to use performance friction pads a few years back Rick. Padget ? pads seem to be the ones now. Brake bias should always be towards the front a bit not 50/50 ?

[steve-e]

Pagid. Mike breitenbach contact details in site partners on the front

[Team RGM]

Finally got around to getting outfit opened up. Master cylinders (AP) front is 5/8", rear/side is 3/4"
Uses balance bar.
Pivot to brake bar 1.5"
Pivot to foot point: 11.75"
Hand pressure to stop: 1.125"
Never good an email back from Mike, what compounds do you run, I'm trying to figure difference between Pagid and PFC PF1s

[Team RGM]

Poke. Any comments?

[Wal]

Hi Rick
By the looks of it your lever ratio is not far out, (although I am not a LCR expert) also the PFC ‘01’ pads that you are using should give you plenty of ‘bite’.

From what you are telling us, it does sound that what you have is about right, set-up wise, which may account for the lack of response.
So perhaps looking for a problem with something not doing what it should, would be the better option.
In Simple terms, the smaller the Mastercylinder bore = greater line pressure, although giving you more physical pedal travel, you will still have good braking at the caliper/disc end.

Meaning, if you want less pedal travel without shortening your ratio, you need larger bore Mastercylinders, the down side of this however is that you will get a harder pedal (less travel), but not necessarily better braking.
The problem of not being able to “lock the wheels” you describe, for me, points more towards a pad/disc problem, as in:
. Glazed discs / pads, can be caused by things like, too much trail braking or foot resting on pedal.
. Pads not pulling away from disc fully (normally caused by lubricating pistons)
. Over heating discs causing fade, caused either by lack of cooling or discs worn too thin (not enough material mass).
. Alternatively, if you are running your brakes too cold, they won’t work well.

In short, all disc/pad combinations have an optimum temperature ‘window’, outside either way will reduce braking power/efficiency.
Hope this helps, Wal

[Team RGM]

Wal, Thanks much, pretty much confirms what we've been thinking. Old pads could be issue here. I do tend to trail brake too much, and system becomes harder (more foot pressure to stop, not more travel) if I'm not careful (keeping foot off pedal).

More foot exercise

Did have brake pressure fade (soft pedal) until switching to Amsoil brake fluid, eliminated the boiling.

Getting ready fore next season.

Rick & Tamera

[666]

Wal, Thanks much, pretty much confirms what we've been thinking. Old pads could be issue here. I do tend to trail brake too much, and system becomes harder (more foot pressure to stop, not more travel) if I'm not careful (keeping foot off pedal).

More foot exercise

Did have brake pressure fade (soft pedal) until switching to Amsoil brake fluid, eliminated the boiling.

Getting ready fore next season.

Rick & Tamera

A friend of mine has a problem keeping his foot off pedal on straights so i made a rest so he could move his foot across and and rest along straights

[oldbelly]

Great as long as he remembers it's the rest his foot is on lol.

[Dan]

I used to put a jubilee clip on the chassis tube where I wanted to rest my foot to hold it off the brake pedal, the clip positioned so that the screw part was what the foot rested on. This was enough to prevent riding the brake pedal but was not too big to need a big movement of the foot to use the brake. In the event of an emergency use of the brake the foot just slides straight off the clip without thinking about it.