"Direct Connection" knob

[xb-60]

Originally Posted by ERA 626

....To test it go to a safe place! ....If the fronts lock up, this will do bad things while heavy braking coming into a turn....

Good advice to do a brake test in a safe location to see how the car behaves.

However....if you set the bias for the rears to lock up first, that would certainly "do bad things while heavy braking coming into a turn"

I would have the fronts locking up slightly ahead of the rears.

Happy driving!
Glen


edit: doesn't that symbol look like a Chrysler Pentastar logo....?

[ERA 626]

Originally Posted by xb-60

Good advice to do a brake test in a safe location to see how the car behaves.

However....if you set the bias for the rears to lock up first, that would certainly "do bad things while heavy braking coming into a turn"

I would have the fronts locking up slightly ahead of the rears.

Happy driving!
Glen


edit: doesn't that symbol look like a Chrysler Pentastar logo....?

Happy to disagree here, if the fronts lock up before the rears, this will put you into a spin that you will not be able to control. If you have slightly more rear bias it will be controllable. The shifter kart is very much like a cobra in a sence that the cobra has suspension the kart does not... Kart racing is the purest form of racing... Love it, live it, do it... If you have never had the experience of 60+ 125cc shifter karts hitting turn 2 at luguna seca doing 100+ MPH at the same time , you need to try it one day... that my friend is racing. Brake bias is a topic that all of us discuss on a regular basis. Trust me I have tried more front bias with bad results, I would rather have no front brakes than more front bias all day long. In fact the 80cc formula class does not allow front brakes.

[xb-60]

Originally Posted by ERA 626

Happy to disagree here, if the fronts lock up before the rears, this will put you into a spin that you will not be able to control. If you have slightly more rear bias it will be controllable. The shifter kart is very much like a cobra in a sence that the cobra has suspension the kart does not... Kart racing is the purest form of racing... Love it, live it, do it... If you have never had the experience of 60+ 125cc shifter karts hitting turn 2 at luguna seca doing 100+ MPH at the same time , you need to try it one day... that my friend is racing. Brake bias is a topic that all of us discuss on a regular basis. Trust me I have tried more front bias with bad results, I would rather have no front brakes than more front bias all day long. In fact the 80cc formula class does not allow front brakes.

Hi Mike,

I'm a little too long in the tooth now to try 100+ mph in a kart, so I can't argue with any authority about brake balance on a modern kart. My karting experience is limited to a home-built kart with rear axle braking only, raced on dirt tracks on my family's property. Kart slicks....wet track....great fun!
So...I'll defer to your experience in fast karts, but I still prefer front brake bias on a road car.

Cheers!
Glen

[Tom Wells]

I'm tempted to say, after looking at this statement:

if the fronts lock up before the rears, this will put you into a spin that you will not be able to control

that this is bass-ackwards from what an average race car will do.

Perhaps with karts this opposite behavior does happen; Experience says that with a race car on a road race track, locking the fronts will not cause a spin, but quite the opposite: the car will basically go straight ahead and understeer right off the racing surface. This is when your braking is being done in more or less a straight line before you begin turning in. If you are braking while turning, you earn whatever happens (unless practicing trail braking, see below.)

If the rears lock first, it is similar to trying to stop an arrow with one finger on its tip. The slightest deviation from straight ahead will result in a snap spin. Same with the car - if a lockup occurs at the rear, you lose the ability to steer and become a passenger!

It's kinda the difference between hitting the wall with the front or the rear of the car - neither is usually good for the car or the driver.

I set my brakes to have the fronts lock a bit before the rears - at least you can steer a little with the fronts locked. Not so if the rears lock.

There is a technique known as "trail braking" where you use the brakes to partially unload the rear tires to assist the car rotating into the entry of a corner. If you're doing this, your driving skills are way beyond mine!

Hope this helps,

Tom

[ERA 626]

Originally Posted by Tom Wells

I'm tempted to say, after looking at this statement: that this is bass-ackwards from what an average race car will do.

Perhaps with karts this opposite behavior does happen; Experience says that with a race car on a road race track, locking the fronts will not cause a spin, but quite the opposite: the car will basically go straight ahead and understeer right off the racing surface. This is when your braking is being done in more or less a straight line before you begin turning in. If you are braking while turning, you earn whatever happens (unless practicing trail braking, see below.)

If the rears lock first, it is similar to trying to stop an arrow with one finger on its tip. The slightest deviation from straight ahead will result in a snap spin. Same with the car - if a lockup occurs at the rear, you lose the ability to steer and become a passenger!

It's kinda the difference between hitting the wall with the front or the rear of the car - neither is usually good for the car or the driver.

I set my brakes to have the fronts lock a bit before the rears - at least you can steer a little with the fronts locked. Not so if the rears lock.

There is a technique known as "trail braking" where you use the brakes to partially unload the rear tires to assist the car rotating into the entry of a corner. If you're doing this, your driving skills are way beyond mine!

Hope this helps,

Tom

Trail Braking THANK YOU bingo... I am 2 time Road Race Champion IN Northern California Karters (NCK) 125cc stock moto class, our biggest most competitive class.
I think we need to agree to dis agree here, I cant speak much for racing a 2400 lb Cobra, however I can safely say I have been around a road race Track on a 110mph Shifter kart 1000+ times. (Laguna Seca, Sears Point, Button Willow, Thunder Hill, Willow Springs, just to name a few. I acknowledge that more rear bias in needed on Thunder Hill west (2 mile track)than Thunder main (3mile track) and a LOT more on a sprint track like sonoma Kart Track, Dixon, Hang Town etc...

I do need to say that Sprint racing is a lot different that Road Racing. On a short tight technical track more rear Bias works better, too much front bias will literally lift the ass end off the ground and cause a violent spin that you will not recover from. But on a Road Race track we tend to adjust per track conditions, the amount of rubber on the track, the temp, tire pressures , chassis tune all come into play while adjusting brake bias. Hence the entire reason for this "mystery knob" that started this thread in the first place.
Bottom Line is every Car or Kart is different, different driving styles, different track conditions all come into play, so perhaps there is no real correct answer here.