braking

[Marc R]

This month MCN tested the Explorer. Here's the performance data.

...
Braking 60mph-0: 127.6 feet, 121.3 without ABS
...

Not a comment on the Explorer, just braking numbers in general. 60-0 in 120ish feet is braking at an AVERAGE of 1 G. Can this braking performance be replicated only by the upper 1% of riders?

I've done a few sessions with my Qstarz GPS and the 749 in a parking lot, 45-0 braking. I'm not a racer, just an enthusiast. During the first second I might reach 0.6 to 0.8 G, the numbers go up to 0.9-1.1 G during the remainder of braking. Braking at an average of 0.8 G. I imagine there are plenty NESR that can reach 1G braking quicker, but is it possible to stop faster than 1.0-1.1G?

Loudog shared a log from AMA racer Rispoli, the log shows him braking as high as 1.7 G (T1 at NJMP). I wasn't sure if it was a bad measurement from Qstarz, or believable.

[PainfullySlow]

I would believe it. I regularly hit 1.4g going into T1 and T3 and I am far from the fastest guy out there.

[Paul_E_D]

Yeah, I don't think you can replicate braking from 170 to 90 on hot slicks in a parking lot on cold street tires. I think that the numbers seem accurate.

[loudog]

Loudog shared a log from AMA racer Rispoli, the log shows him braking as high as 1.7 G (T1 at NJMP). I wasn't sure if it was a bad measurement from Qstarz, or believable.

That 1.7 g figure is a peak (and should be taken with a grain of salt), not an average as would be calculated using a stopping distance. Rispoli hit an average of -0.98 g going into T1 at Jersey in the data I have. That's pretty much as good as it gets as far as average braking on a race bike. Like others said, you can grab higher peaks...but not sustained braking.

[OreoGaborio]

That 1.7 g figure is a peak (and should be taken with a grain of salt), not an average as would be calculated using a stopping distance. Rispoli hit an average of -0.98 g going into T1 at Jersey in the data I have. That's pretty much as good as it gets as far as average braking on a race bike. Like others said, you can grab higher peaks...but not sustained braking.

Now I'm curious... what was mine?

[loudog]

Now I'm curious... what was mine?

Yeah, it's really a good number to know. Gives you an idea if there is more in there somehow. On sports bikes though, you get a pretty good indicator of when you're at max braking...the rear tire coming up. Well, if you're braking in a straight line. Trail braking is another story.

I'll calculate yours in a few spots this weekend Pete and post up. I'm curious myself. I'll be doing the same with my data to see what difference my new pads made.

[Marc R]

Thanks for the input guys. I was assuming you couldn't exceed 1 G by much, without down-force providing additional traction.

Lou, agreed; 1.5-1.7 G values are seen in one and occasionally two samples (0.4 sec).

Here's a graph of Rispoli at NJMP T1. Gs are in blue with the scale on the left. MPH in purple, scale on the right. Samples are 0.2 sec apart. Notice he starts braking at 150ish mph and reaches 1G of braking in 0.4 seconds followed by 1.5G. You can't brake this fast with the common advice of "squeeze, then squeeze harder".

[Paul_E_D]

Wirelessly posted

Yes you can, it just happens really fast. You can't just grab as quick and hard as possible. Close, but not quite...

[loudog]

So, here are a couple graphs showing Pete and me braking into 1 and 3. The graphs show speed on the y-axis and distance on the x-axis. These are from our fastest laps of the last round (though, Pete is a bit of a wounded duck).

Pete in 1:



The white dot represents the point where Pete begins to trail brake. Before trail braking, Pete is pulling an average of -0.73 g's (1st red dot to white dot). Including trail braking, he is pulling -0.65 g's (red dot to red dot).

Lou in 1:



I pull about the same initial braking rate as Pete, but I start to ease off the brakes way before he does, and that pulls my total braking rate down to a weak -0.49 g. At least I know I have a lot of room for improvement.

Same thing for turn 3, though I'm easing up at a more reasonable spot for T3.

Pete in 3:



Lou in 3:



It's interesting that both Pete and I are topping out around 0.8 g's. For me, in three, I know I stop there because the rear is dancing around so much. But, maybe there is a bit more to be had. I know we're not on the best set-up bikes in the world, but I imagine a 0.9 is possible. But, I dunno, maybe we're limited by the geometry and weight distribution at 0.8 +/-. I'll try scooching back a bit more in the seat...

[OreoGaborio]

Very cool!

[Paul_E_D]

Lou. In 3 there is a lot of braking potential to be gained by scooching all the way back in the seat and pinching the bike. Move forward and off 2/3rds of the way down the chute.

[loudog]

Thanks Paul! I'll give that a shot next round.

[Marc R]

Wirelessly posted

Yes you can, it just happens really fast. You can't just grab as quick and hard as possible. Close, but not quite...

The way I apply "squeeze, then squeeze harder" is actually "squeeze, wait to feel the front compress, then squeeze harder"; safe but not the fastest way. Sounds like braking would improve when continuously squeezing more (never pausing); the rate of squeezing would start slow and then progressively faster/harder, to reach max braking within one second (or so).

In post #7, Rispoli is reaching 1G braking in 0.4 seconds and max braking of 1.5G in 0.6 seconds.

[nt650hawk]

I've got to learn how to use this stuff. maybe I need a class Lou.

[Kurlon]

Am I the only one concerned that the Explorer needs more distance to stop with ABS enabled? Sounds like a faulty setup.

[JettaJayGLS]

Really cool stuff...maybe I need one of these, I'd be curious to see how the 'tard does.

[RyanNicholson]

The way I apply "squeeze, then squeeze harder" is actually "squeeze, wait to feel the front compress, then squeeze harder"; safe but not the fastest way. Sounds like braking would improve when continuously squeezing more (never pausing); the rate of squeezing would start slow and then progressively faster/harder.

You have the right idea, but a bit backwards. Typically you want to get 80-90% of your braking done as fast as possible, BUT you have to apply it smoothly to do it. If you're coming into T1 and you get to your brake marker you need to smoothly but quickly SQUEEZE THE PISS OUT OF IT, then trail off and adjust to your entry speed. The harder/later you do this, the faster you're entering the corner. Riding fast is all about managing drastic changes in speed quickly and efficiently (that goes for both braking and accelerating).

The way you described it you'd be doing your hardest braking in the corner. You probably don't want to do that

[union]

Really cool stuff...maybe I need one of these, I'd be curious to see how the 'tard does.

they have brakes?

[jasnmar]

Am I the only one concerned that the Explorer needs more distance to stop with ABS enabled? Sounds like a faulty setup.

Seems pretty typical of ABS setups from what I can tell. I know the ABS version of both the Goldwing and C14 take longer to stop than the non ABS versions. The advantage of ABS is that it stops in the same distance even when the passenger panics and just grabs handfuls of breaks.

[Eric Baker]

Am I the only one concerned that the Explorer needs more distance to stop with ABS enabled? Sounds like a faulty setup.

Anything will take longer if the abs is activated and working properly. The whole point is to keep the front tire moving. This can be detrimental to stopping distance if the available grip is high.

[JettaJayGLS]

they have brakes?

6 Piston front setup combined + no weight + no entry speed + high corner speeds = extremely short braking zone

it sure is fun.

[csmutty]

6 Piston front setup combined + no weight + no entry speed + high corner speeds = extremely short braking zone

it sure is fun.

WOuld you mind if I took it out for a race sometime? I've been jonesing hard core.

[Marc R]

You have the right idea, but a bit backwards. Typically you want to get 80-90% of your braking done as fast as possible, BUT you have to apply it smoothly to do it. If you're coming into T1 and you get to your brake marker you need to smoothly but quickly SQUEEZE THE PISS OUT OF IT, then trail off and adjust to your entry speed. The harder/later you do this, the faster you're entering the corner. Riding fast is all about managing drastic changes in speed quickly and efficiently (that goes for both braking and accelerating).

The way you described it you'd be doing your hardest braking in the corner. You probably don't want to do that

Oops, just edited my post #13; which I (intended) to describe reaching max braking (what happens in the first second of braking).

[OreoGaborio]

I don't set, then squeeze. At least not anymore... while it WAS a good habit for me to get into at first to remind me to set the front end, once I knew and didn't need that reminder I stopped.

Now I'm using a roll off & sqUEEEZE technique in order to get close to maximum braking as soon as possible. Then I hold maximum pressure as steady as I can (modulate as needed to keep the rear tire on the ground) until I begin leaning, then I trail off.

[JettaJayGLS]

WOuld you mind if I took it out for a race sometime? I've been jonesing hard core.

Sure, but I think all my races overlap with the expert ones...maybe not ULSB, but Gino may kill you.

I'll be at the August 13th Tony's day, if you're there feel free to take it for a spin.