Karting1.co.uk

[nowysz6]

Alright, here's what I've been thinking, and I'll try to explain it as clearly as I can. I keep hearing that trail braking is fast because it lets you hit the same apex while braking later into the corner, which allows you to be at 100% throttle for longer before the corner. So lets assume that to get through a corner the fastest way possible, you need to use all of the grip from the tires for 100% of the time you're cornering. Assuming you brake in a straight line, and then transition to trail braking for the entry, you would be using some of the tire grip for braking, and some for cornering. To keep using 100% of the grip, you would need to slowly turn the steering wheel more and more as you ease off the brakes to transition the grip from braking to cornering. This would mean your line will be a decreasing radius, taking away momentum. I've always thought that in order to get to the apex at the highest speed possible, you would need the widest constant radius line possible (100% of grip used for cornering). This would mean that if you trail brake on entry, you won't be arriving at the apex at the highest possible speed (but you get there sooner), and your exit would be slower because you would lose your momentum and have to accelerate more. So in general: how is it possible to trail brake and still get the fastest exit possible, and why should this be faster than using straight line braking and a constant radius line through the whole corner?
_________________

[DGorman]

[nowysz6]

[Christian]

It's an interesting topic, I wouldn't presume to know the answer, but just a few more things to think about:

Only the rear wheels brake -> When you're turning one of your rear wheels is off the ground -> doesn't that mean that braking whilst turning is only half as efficient?

Is true 'trail-braking' then just braking in a straight line with both rear wheels planted, but the whole karts 'Yaws' clockwise (for a right-hander) so you also get the kart turned into the corner.

Theoretically that seems to be the most efficient way of doing it, it just seems to go completely against the principle of lifting your inside rear when cornering..
_________________
Proud member of the YUKC! www.yorkunikarting.co.uk

[Larry]

This is my experience. It depends on the kart chassis, some karts can be driven fast using a slight amount of trail braking. Other karts are very intolerate of trail braking and work better using the straight line braking method.
Larry

[awi]

When cornering, kart leans towards outside front tyre. Braking while turning only increases the effect. Friction - in most simplistic interpretation - is not relative to area of contact patch. In case of rubber against tarmac it does matter, but not that much. So no problems there.

Fasteest racing line is late apex line because of exit speed, not round curve but rather a bit pointy elliptical curve before the apex. Pointyness results naturally from reduction of speed while cornering, changing the direction eats its part away from momentum. I've been thinking that trail braking works because you just can't set the kart straight to its maximum lateral G force, so it lefts you bit of unused friction for braking. This is where I think the fast setup excels, it sets quickly and rolls nicely so the line is less "pointy". You can go near on lock just to turning point and just turn in and roll out, no fuzz and no speed loss.

[T.J. Koyen]

I trailbrake a lot.

To be quick around the corner, you must load the kart using your feet, shoulders, and hands. A smooth transition from braking/turning/throttle keeps constant load on the outside tire and will keep the kart stable. Trailbraking helps me to make all these transitions much smoother so I'm able to load the kart quickly and with a fairly constant force, the kart is stable, I'm able to confidently and quickly get on the throttle and power through and off the corner.

I'm kinda over the debate about straightline vs. trailbraking because in reality one style won't work for every corner and you have to know how to approach each corner and each series of corners to get through them as fast as you can. If each corner on every track had a long straight before and after, you can then maybe break down each corner more specifically on how to drive them. But tracks aren't like that. There's bends and corners right next to each other. You have to then attack and compromise to get through those sets of corners quick, rather than trying to nail each individual corner.

Both techniques have their merits. Some drivers do more straightline braking, some do more trailbraking, but the best drivers are the ones who can use both techniques when they are applicable. I doubt Senna ever calculated what turn radius was best or what % of grip he was achieving at what section of the corner. He just knew what felt right and he knew when he was going through the corner where he had to place the car/kart, what his feet had to do, what his hands had to do, in order to get from entry to apex to exit in the shortest amount of time.
_________________

www.OKTANEVISUAL.com - custom helmet paint and graphic design

[A.Farrell]

trail braking depends on how grippy the surface is.

i didnt read the above its to long. i hope iv helped though

[nowysz6]

[T.J. Koyen]

[Chuck McCue]

Trailbraking must be done properly, I don't tell newbies to do it. If you don't modulate properly the inside tire drops and kills your exit speed.
_________________
Chuck McCue
Arsenal Racing
www.arsenalracing.com