Brake Bias

[Mark Smith]

I would like to know the fundamentals of brake bias settings.
I have a Birel CQ32X 2001 chassis with the old style freeline brake system.

[Sam Cooper]

Mark,

Each person has his/her own "bias set-up" - so there is no "exact" setting for it....
The way we do it is:
Set the bias to the rear all the way.
With the kart on the stand - roll the front and rear wheels on one side (with another person holding slightly on the brake pedal) and adjust the bias to have just slightly more brake to the rear by turning the bias adjuster towards the front master cylinder until the front brakes start to grab = Rear wheel should be harder to turn than the front with the brakes applied.

Too much bias to the front will cause the steering to "jerk" when braking, too much to the rear will cause the rear to lock up under hard braking..

After you have set it up on the stand, take it on the track and adjust to your personal preferences by turning the bias knob either to the front or rear for your driving style.

Another major factor is to make sure the brake rod that attaches the pedal to the master cylinder is not too tight (pulling the master cylinder arm forward) causing the front or rear brake to be applied too soon when braking - They are to be used to "fine tune" the pressure that needs to be applied for braking or "when the brakes come in"..

I have seen customers have fits over the brake system due to improper bias, air in the brake lines or worn pads.

With a proper set up brake system, your master cylinder arm should move no more than 1/2" when the brake is applied by hand. If it moves more than that, you have worn pads or air in the lines.

Hope this helps....

Sam Cooper
Speedwerx Motorsports U.S.A.

[Mark Smith]

Thank you Sam,

I will put those principals to work next track day. At least now I have a starting
point.

Take care

Mark

[Sam Cooper]

No problem!
That's why we have this forum :-)

Sam Cooper
Speedwerx Motorsports U.S.A.

[Garry Lobaugh]

Nice job on this Sam and I thank you for staying tuned on the forum. A new issue came up this weekend on day one with John Branam. He overheated the brakes by using a trail brake style technique. As you know, I'm not a fan of that method. We had to releive the pressure by taking off the fill plug on the master in order to allow the fluid to cool and the lines to vent. After that we refilled the lines with fresh fluid to completely flush the system and get him up to full braking use before the feature. In the feature he was right with the winner and teamate Josh Schreiber in the ICC one two finish for Stars East.

In terms of your example Sam, it is often best for the customer to cruise around at a slow speed to check and adjust the bias on the track, just to fine tune the settings.