Body position for hard braking

[Petorius]

This is something that has been bugging me since the end of last season. I learned, from multiple TD organizations, to set my body position before beginning to brake for corners. Coming down the front straight, I get my ass off early, then set the brakes, etc. However, while watching experts going into T3 at NHMS, I noticed that the vast majority of the fastest guys do 90% of their braking while sitting centered on the bike, then make a visible body position adjustment to get off the bike just before making the steering input into the corner. I would have just assumed that the early change in body position (as I learned) was just imperceptible due to the speed or something, except that the real body position adjustment is so big and obvious that you cant miss it when watching from the T3 stands.

What gives? Is this just a unique case for T3 since you have to make the slight bend to the left into the chute before setting up for 3?

[Paul_E_D]

It's not the slight bend IMO. It is the bumpiness, combined with the intensity of braking. You can stabilize the bike and keep the rear end down by inching back on the seat and squeezing the bike with your knees MX style.

[Paul_E_D]

Also, the absolute quick turn lends itself to moving over ant tipping in hard in one smooth motion.

[Petorius]

Thanks Paul, that is definitely the answer.

/thread

[tsorfas]

It's not the slight bend IMO. It is the bumpiness, combined with the intensity of braking. You can stabilize the bike and keep the rear end down by inching back on the seat and squeezing the bike with your knees MX style.

I agree with Paul

T3 is so bumpy that you need both your knees squeezing the tank in order to keep stable.
Also T3 has a lot of trail brake as well.

[csmutty]

I squeeze with both knees with my butt off to the right side of the seat. Then all I have to do is stick my knee out and...voila.
Took me a bit to figure out proper placement of the inside leg in order to get grip while your butt is off the seat. I usually get my butt off the seat either before I start braking or while I am braking.

[Paul_E_D]

as long as it doesn't make you wimpy on the brakes, Smutty's technique is good too. A lot depends on the bike as well, but in extremely hard braking zones I often center up to help prevent the rear from trying to pass the front.

[csmutty]

as long as it doesn't make you wimpy on the brakes, Smutty's technique is good too. A lot depends on the bike as well, but in extremely hard braking zones I often center up to help prevent the rear from trying to pass the front.

Taking all the fun out of it!

[Paul_E_D]

True. but it's fast.

[csmutty]

But especially in T3 I don't do a terrible amount of trail braking. For me the goal is to get back on the gas asap, even if it means getting on the brakes earlier to build speed for the hill and turn 5...err...straight. I had always tried to late brake that corner and always ended up losing time because of it.

[Paul_E_D]

I agree. the trail braking zone is very short in T3. It ends at the rumblestrip IMO. off the brakes and on the gas by the corner of the pavement patch.

[csmutty]

Yup. And then full throttle (bike dependent) at the dip when the suspension gets fully loaded. That is such an awesome feeling shooting out of that corner when you do it right.

[carsick]

Go on...

[tsorfas]

I agree. the trail braking zone is very short in T3. It ends at the rumblestrip IMO. off the brakes and on the gas by the corner of the pavement patch.

I think that's a lot of trail braking. Maybe not in distance but time (counting the total time you spend braking).

One of the mistakes I used to do (and plenty others as I found out later) was doing no trail braking in 3. I used to do all my braking while the bike steaight and then drop it.

Now it's starting with smooth braking early instead of stabbing the brake, trail break until the rumble strip where I completely let go the brake and reach maximum lean to finish the turn and get on the gas.

[Ductard]

....and just in case anyone is wondering...do not trail brake ON the rumble strips. It doesn't work out so well.

[Paul_E_D]

Good point, that why I said off em by the rumble strip! It's only about 30 feet from tip in the rumble strip, and at speed, that is over in an instant. Basically if you start releasing the brakes right at tip it and just ease off them over like 1 second, that's it.

I actually don't think there's any penalty in time for not trailbraking in T3. Yes, it's a little rougher, but I can turn the same laptimes either way. Where it really comes in handy is for passing on the inside.

What DOES yield better lap times according to my data is doing your hardest braking closest to the corner. Pretty much the opposite of what most people do. So ease into the brakes relatively speaking and reach max pressure halfway down the chute.

[Paul_E_D]

Here's what it looks like in data. This compares 4 riders from our 125 endurance team. Pay attention to the tops of the curves. The second tall one is T3. You can see that the fastest rider had a smoother transition from throttle to brakes, carried more momentum through the first 1/3 of the braking zone, and was the first one OFF the brakes (bottom of the curve). The slower riders show a sever dip in speed right at the beginning of the braking zone, and they trail brake deeper.

This pattern holds true for most corner on the track, and is pretty much responsible for the difference in times. Brakes are definitely where people lose a lot of time.

[xsiliconkid]

T3 NHMS
Entering T3 there's a lot going on. just think what the suspension has to achieve from entry through exit.
- any unnecessary input (body poistion) into suspension when already "overloaded"should be avoided.
True the key to T3 is late hard braking and quick turn in. You can't sacrifice maximing effort here..but you can prepostion your butt so unnecessary input through the pegs/bars is minimized when suspension has to work overtime.

- Right at the tip in point there is a huge transition of tire traction force via loaded suspension (braking)to cornering force loading (centrifugal) If the transiton isn't executed perfectly the suspension may raise (unload) too fast. Trail braking aids in keeping the correct load through the suspension ( just like in any corner but in T3 everything happens so quick).
Just like you get your downshifts down before the tip in point under braking you body positon should be set before this.
Hanging off the bike with maxim braking and not adding load to the front suspension is an aquired art.

- concering entering T1 and getting body into position....if T12 was connected directly to T1 you would stay in a left hand entry body positon... The straight (especially on middle weight bikes and up) is not long enough for much aerodynamic
benefit. You can stay with your butt off to the left all the way down the straight eliminating one more activity to worry about entering T1.

[Petorius]

That is great data. The curves through 9 and 10 are interesting too. The little upwards inflection point just before the braking zone for 10- is that an upshift by the treehouse? I also have no idea what the peak at the end of the braking for 10 is.

[Paul_E_D]

I do not brake for 10. I get on the gas harder than most between 9 and 10. Just rolloff to tip it in hard for 10. That turn in alone scrubs the speed.

[Petorius]

Wow, I'm not sure if my memory is rusty or if I am just leaving a lot of speed on the table from 9-10. I think I stay completely off the gas until just before the transition in 10, I might even brake a little bit before that.

I can't wait for round 1!

[TheIglu]

I do not brake for 10. I get on the gas harder than most between 9 and 10. Just rolloff to tip it in hard for 10. That turn in alone scrubs the speed.

I don't either. I just let Pete's bike slow me down enough for the NASCAR jump.

[cdovego]

as long as it doesn't make you wimpy on the brakes, Smutty's technique is good too. A lot depends on the bike as well, but in extremely hard braking zones I often center up to help prevent the rear from trying to pass the front.

He pretty commonly had the rear wheel off the ground going into 3, definetely didn't make him wimpy. Dude was a stud going into 3.

[Paul_E_D]

Wow, I'm not sure if my memory is rusty or if I am just leaving a lot of speed on the table from 9-10. I think I stay completely off the gas until just before the transition in 10, I might even brake a little bit before that.

I can't wait for round 1!

You're not alone, most people leave a lot on the table there... and in every turn.

And Dove, I'd say I'm pretty familiar with Christian's riding. I was implying that hanging off early in T3 can slow most people down, not that it was slowing Christian down.

[Ductard]

Here's what it looks like in data. This compares 4 riders from our 125 endurance team. Pay attention to the tops of the curves. The second tall one is T3. You can see that the fastest rider had a smoother transition from throttle to brakes, carried more momentum through the first 1/3 of the braking zone, and was the first one OFF the brakes (bottom of the curve). The slower riders show a sever dip in speed right at the beginning of the braking zone, and they trail brake deeper.

This pattern holds true for most corner on the track, and is pretty much responsible for the difference in times. Brakes are definitely where people lose a lot of time.

I had a different set of takeaways from that graph. Not necessarily in opposition to your observations...

I highlighted the fastest rider's braking zones (red) and acceleration zones (green).

I *think* I identified turns 1, 3, 6, 9 and 12 and labeled them.

Notice that speeds through the braking zones are almost identical (except going into 9 and 12).

The biggest difference is the faster rider gets on the gas sooner and carries that higher speed through the entire acceleration zone.

Notice the faster rider has a crisper transition with the only gap between major braking and major drive zones (white spaces) between 1 and 2 (aka 1a), 9 and 10, and a TINY little sliver between T6 and T9 (probably the right/left transition going into 9). Even the 1/2 and 9/10 sections for the fastest rider have distinct mini-acceleration/braking zones, just smaller than I feel like noting on the graph (as a matter of fact, kudos for how little coasting you're doing).

Also, notice that the "back straight" isn't really the second longest acceleration zone....by distance or speed differential at the start/finish of the drive. That would be T4-T6 by both counts.

The biggest difference I see in T3 is that the fastest rider is on the gas sooner and carries that speed through the entire T4-T6 section.

What's also interesting is the 1:19 guy vs. the two 1:22 guys....drives are almost the same except the two 1:22 guys either have less powerful bikes or (more likely), they are doing what Eric Wood points out on every track walk....rolling off after coming over the hill and not using the T6 braking zone to the fullest.

....there is not a lot of time carving/maintenance throttle on this track.....