No, you're not Steve McQueen and you never will be!

You will need to brake hard and late at the end of the straight, to keep up with the faster bikes.

And to stop that fat 230kg motorcycle, you will need good brakes!

Here is a guideline to get a good set of brakes on your 7.

Braided steel brake lines

First things first!!

You HAVE to bin those rubber brake lines. Those lines are old en worn out.

If you still got those 25 years old rubber lines on your bike, You should change them immediatly. I hope you check the condoms in your wallet more regulary, we don't need you guy's to reproduce...

These rubber lines will swell under the pressure caused by applying the brakes. Your brakes will feel “soft” and don’t respond quickly.

Bin that hose splitter as well. Just start with 2 hoses from your master cylinder directly to your calipers.

You will need a larger banjobolt on your MC. In a good kit, that is already provided.

Brake fluid

You have to keep 2 things in mind when it comes to brake fluid

1. Moisture

Brake fluids are very hygroscopic,meaning they will absorb moisture when exposed to air.

Moisture can be absorbed through brake lines or the brake fluid reservoir even when the vehicle is not driven.
After a year in service your brake fluid will absorb about 2% of moisture.

This decreases the boiling point of your brake fluid and make it feel 'spongy'.

2. Heat

Your brakes will get hot on a trackday. This heat can cause the brake fluid to boil, creating gas bubbels.

As gas is far more compressible than liquid, you will experience no pressure at all on the brake lever, resulting in total loss of brake power known as vapour lock.

What you need is a brake fluid with a high boiling point to prevent vapour lock and keep that boiling point high by frequently changing your brakefluid!

OK, I just get me some 5.1 fluid. That's got a higher boiling point than 4.0

Not really.... if you compare a regular 4.0 and 5.1 fluid. The 5.1 will indeed have a higher boiling point.

But the downside of 5.1 is that it's more hygroscopic then 4.0. So it will attract more moisture and the boiling point will drop fast!

Just get yourself some good DOT 4 brake fluid like RBF 660.

Master Cylinder and calipers

OK, I just slap a big 19mm radial MC on my bike instead of that stock 16mm axial MC. Bigger is better, right?

Hold your horses mister p*rnstar, bigger is not always better!

There is a lot of information to be found on the world wide web. Some good advice but also a lot of bullshit!

I bumped into some advice of TBR Performance and it's explained very clearly.

I'm just going to quote it here:

Hopefully this will dispell a few myths and confusion around master cylinders and upgrades:

for a given amount of hand force:

• smaller piston diameter & smaller lever ratio = more line pressure = more force, BUT equals more lever travel
• larger piston diameter & larger lever ratio is the direct opposite = less line pressure = less force, BUT equals less lever travel

Hydraulic advantage comes from the difference in master cylinder bore (& lever ratio) compared to the caliper pistons... so the bigger the master bore, the closer you get to the caliper pistons area, the LESS force you get.
Imagine if the master cylinder was the same size as the caliper pistons, it would be the same as directly pushing on the caliper pistons with a 1:1 ratio, and so only the force your hands could produce would go to the caliper - and you'd crash at the first corner.

However it's not so black and white, on track the calipers get red hot, especially compared to road use... they expand and the difference between caliper and piston becomes larger.. so you get more lever travel from the stock master cylinders (which are sized generally for road use where the brakes dont get anywhere near as hot)
So with heat the calipers get bigger, or in other words, the master cylinder gets smaller in relation to the calipers - and from above - this equates to more lever travel

on top of this, any micro bubbles of air in the fluid expand, which can then be compressed when the lever is squeezed - again = more lever travel.

Additionally or as most people know, if you have old fluid or any moisture in the system, this then boils off and becomes compressable gas = more lever travel

and then to further complicate things, you have flex in the calipers themselves, stiffer caliper = less lever travel for a given amount of force
more flexible caliper = more lever travel for a given force

The master cylinders also get hot, and with cheaper master cylinders, the bore doesn't maintain it's roundness and the seals let fluid past instead of pressurising the system ( a small amount of course but it all adds) fluid getting past the seals = more lever travel

levers themselves flex = more travel, sometimes a master cylinder can be improved by simply changing the cheap stock cast ally levers for a good quality billet aluminium (and maybe change the lever ratio at the same time)

so for instance Brembo M50 calipers have 30mm pistons all round, and are very stiff, well made calipers, made from high grade aluminium to a design that stops too much expansion and flex, and heat transfer into the fluid - brembo suggest using a 16x20 master cylinder - and this combo works well

ZX10R calipers also use 30mm pistons all round, but the calipers aren't anywhere near as well designed and the 16x20 brembo master cylinder doesn't work because the calipers do all of the negative things mentioned above

R6 calipers, have even smaller pistons (2 x 27mm and 2 x 30mm) the stock R6 master cylinder is 16x18... but on track becomes mushy are a few laps as everything heats up, for the first few laps they feel great with loads of power, but when they get too hot, the lever can be almost back to the bar. so you go bigger on the bore and lever ratio to compensate for the poor caliper design
(17x20 or 19x17 are where you want to be - if you have a powerful grip then maybe 19x18)
But if you go too far and fit a 19x20 with calipers that have such small pistons, then the lever will feel rock hard, you transmit way less force to the pistons, so you have to squeeze like buggery to get enough braking force, you create awesome conditions for getting arm pump! and your brakes have no feel. 19x20 master still works just fine, but it's very on/off and more difficult to regulate braking force - which riders describe as having "no feel"

lever ratio is essentially doing exactly the same thing as bore diameter. it's just a handy parameter that can be adjusted (you can also adjust it by simply grabbing the lever further or closer to the master cylinder)
2mm of lever ratio = 1mm of bore size - so a 19x18 MC gives the exact same overall ratio as an 18x20 MC (if they were available) 18x18=17x20 and so on.

Essentially when upgrading brake systems, we want to reduce flex, which creates lever travel without transmitting force to the pads. and we want to optimise the overall leverage ratio between master cylinder and caliper in a given circumstance (i.e. when very hot for track use, or not so hot for road use.

so in general, for track you want a master cylinder with a slightly larger bore and LR, but not too much larger
you actually get a bit less overall power in theory... but if the master cylinder that gives you more braking power is hitting the handlebar under braking, then it's not giving you anything at all! - you could change the calipers... but that's way more expensive!

with regards to the billet vs forged master cylinder - billet master cylinders are machined to tighter tolerances and maintain their shape better under heat and pressure, and so the seals can hold pressure and transmit force more efficiently

TMP Summary

Our knowledge about brakes is the size of a peanut. A small one... like our brain.

Although the advice of TBR brightens up some things, it's not very clear what to do with our zx7r.

We will share our setup that works really well for us:

• Braided steel brake lines front and back:no brainer here
• Motul RBF brakefluid. 600 and 660 works great
• MC: we use the Brembo RCS 19 and the Bremco 19x20. They never let us down. Before that we used some 'brembo' 19mm MC you find on a stock Ducati and Triumph. Yes, those are real brembo's but we felt a difference in flex compared to the Brembo RCS and 19x20.

• Calipers: those Tokico 6 pots seize fast, terrible to bleed and needs a lot of maintenance. Instead of refurbishing those crappy calipers every 2 trackdays, we got us some Nissin 4 pots.  We bought these calipers brandspanking new and they work great with Brembo brakepads! The Nissin calipers are easier to bleed and maintain. the pads are smaller and don't tend to warp like the ones of the 6 pots.                       

     They also weigh less! And that's unsprung weight...      

      On 1 bike we still use the Tokico 6 pots with the Brembo 19x20. We believe these are the only Tokico 6 pots ever made that last...

     So you can be lucky but don't count on it.

• Brakepads: we use Brembo RC  brakepads                   

Nissin 4 pots with 90mm pitch centre distance will fit your zx7r.

You can find them on:

• Suzuki Bandit 1200 (1997-2000)
• Suzuki RF900 (1994-1997)
• Suzuki GSX-R400 (1990 - 1994)
• Suzuki GSX-R600W (1993)
• Suzuki GSX-R750L (1988-1990)
• Suzuki GSX-R750N (1991-1992)
• Suzuki GSX-R750W (1993-1995)
• Suzuki GSX-R1100K (1989-1992)