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View Full Version : Braking to throttle transition, and vice versa



NORTY
06-03-2016, 09:21 PM
Here's my question (well, actually many questions)~

Let's say you're braking into a turn, heading for the apex. At what point do you release the brake(s) totally and apply throttle? Do these two operations overlap? If so, how much? They do overlap in 4 wheeled vehicles.

Conversely, would a rider still apply brake upon corner exit to settle front suspension further? It seems to me that a rider would want to transition as smooth as possible to avoid upsetting the motorcycle. Wouldn't less tire wear be the result if done correctly? And better contact patch?

Which brake? Front or rear? Does the ratio of brake force (fr to rr, or rr to fr) change with the corner entry/exit?

How about rain. Does reduced friction change the above answers?

I know the bias is fixed in 4 wheeled vehicles, so adjusting "front to rear" during a hot lap is a non issue. But with motorcycles, it's different.

This should be fun!

GO!

LoDownSinner
06-03-2016, 10:20 PM
Trick question.

If you can release the brake prior to the apex, you've probably braked too early.

A lot of the finesse and genius that makes someone good on the brakes is that they know exactly how much and when to brake to be able to get the appropriate load on the front tire and have it slide just enough. Like Ed Bargy says, "If the tires aren't sliding, you're not going fast enough." Oddly enough, underbraking is as likely to cause the front end to slide too much as overbraking, underloaded vs. overloaded {EDITED TO ADD - at race pace, underbraking is not so much of a problem just running hot laps}.

The fast guys tend to view both of the controls on the right handlebar as one, easing off the throttle as the brake is applied and conversely easing off the brake as the throttle is applied.

I don't know anyone fast who actually uses the rear brake once they pull out of the pits. Well, maybe unless they run off the track.

Settling the suspension is a good question. I dunno, that sounds like 'comfort braking,' using the brakes to make yourself feel better when it's not absolutely necessary.

Rain? Again a trick question. It's the same. You set your brake marker so you finish braking at the apex. You'd be absolutely amazed how much traction rain tires have. Granted, they're soft and sticky enough that they turn into bubblegum if you push them on a dry track, but they're amazing in the wet.

So with all of that being said, are you asking about racing to win, racing to compete, racing to participate or running fast laps at a track day? They're all totally different things, each one an order of magnitude above the other.

asp125
06-04-2016, 12:55 PM
Brake till the back tire leaves the ground, downshift and clutch out to kick the rear end out, stick the inside leg out, back it in trail brake to the apex and full throttle out letting the traction wheelie control software do it's thing. At least that's how it appears on motoGP. :-/ ;)

Sent from my SAMSUNG-SGH-I747 using Xparent Skyblue Tapatalk 2

NORTY
06-04-2016, 02:22 PM
LDS~ thanks for the informative reply. My motorcycle competition experience is only Dist 38 Desert racing. Done track days but no competition on asphalt. Well, I did do some bracket racing on the 1320, but this doesn't apply.
Tried to not make it a "trick" question. Maybe it's just my unfamiliarity.

AZridered
06-04-2016, 02:57 PM
Like Ed Bargy says, "If the tires aren't sliding, you're not going fast enough."

Funny, (there's a story that leads up to this) I once asked my son how he knew how hard he could trail the front brake into a turn, "Until the back end starts to come around." was the very matter-of-fact answer. Probably a bit more than I actually wanted to know. I only push it to the point where the bike asks, "Are you sure?"

AZridered
06-04-2016, 03:12 PM
I'm off of the brakes prior to the apex. Brake pressure drops as lean angle increases with braking hitting zero before lean angle is at maximum.

Throttle and brake together? Only if I'm keeping the idle high by not fully closing the throttle. I prefer to use an elevated idle speed to help with rear wheel control under braking, but sometimes I cannot make this adjustment (my Buell). In those cases, I just keep the throttle open a bit. I don't add throttle with brakes on.

Use of the rear brake? On my R6 I use the rear brake to control wheel spin at corner exit. Something that I learned in the dirt. With a worn tire, or maybe damp track conditions, I use the rear brake to keep rear wheel spin under control. Rolling off of the throttle takes too long and produces a 'long' reaction. On top of that, the chassis loading changes (which might be bad). A little rear brake is quick and easy. I just need to not forget where the pedal is located because I use it so infrequently. On my Buell, the rear brake definitely helps to keep the bike settled on corner entry. In the case of the Buell, I am off of the rear brake pretty early into a turn, well before the front is done. For the R6, the rear tire gets so light under braking that there's really no grip left to allow rear brake use. Engine braking can be more than enough to start a slide.

Rain just lowers the maximums and lengthens the transitions. I've never ridden on true rain tires.

Of course, all of the above is definitely track-only

LoDownSinner
06-04-2016, 03:16 PM
LDS~ thanks for the informative reply. My motorcycle competition experience is only Dist 38 Desert racing. Done track days but no competition on asphalt. Well, I did do some bracket racing on the 1320, but this doesn't apply.
Tried to not make it a "trick" question. Maybe it's just my unfamiliarity.

Man, I have a vintage YZ400 that would love to come out there and do some desert racing!

And actually, I'm a firm believer that riding on dirt is one of the greatest preps for roadracing. It allows you to develop the confidence, reflexes and responses to be able to handle those times when the bike gets a little loose. If you watch the really fast guys, you'll see that nearly every turn is taken in a light two-wheeled drift, kind of like on sand, but MUCH less. Being someone "who races to participate," I have no clue how they do it consistently...

OBX-RIDER
06-04-2016, 05:25 PM
Good stuff. I was a finish the braking then turn the bike rider for years. This way seemed to be supported by the number of professional riders who crashed trail braking. Having ridden on the track with someone who was 11th in AMA supersport at the time told me how good I wasn't. Besides it's what I learned at CA Superbike and Cornerspeed. Understand I braked hard ... the rear wheel would be hopping ... and I "flicked" the bike quick ... but I could understand intellectually that I was missing something. When Cornerspeed (VIRs motorcycle track school) started teaching trail braking ... I began to reconsider.

Cornerspeed emphasizes that when braking the front fork is compressed ... and the bike turns easier and faster with the fork compressed. Yet the way I was doing it ... the fork is compressed... brakes released ... forks extend ... bike turned ... forks somewhat compressed ... boingo ... boingo ... Trail braking ... braking... compressed ... as you ease off brakes turn ... forks stay compressed ... not as much as braking but some.

I have to add a caveat. I watch a lot of Moto3/Moto2/MotoGP ... free practice/qualifying/race ... so I see a lot of really really good riders ... crash trail braking. Mebbe just a little too much brake ... like 41% when the cornering is using 60% ... so my brake/corner is more like totaling 90%. Ideally braking goes to zero as cornering comes to 100 or maybe 99%. With me braking is zero when cornering is mebbe 80% then I continue to 90-95%. I'm ok sliding the rear tire ... a little. When I slide the front tire it is either a) a mistake ie. I went off throttle momentarily or b) I am riding over my head ... :-|

asp125
06-04-2016, 05:59 PM
I used to brake in a straight line, as taught in MSF, then flick the bike over. After a session with one of the now Yamaha Champions Riding School instructor, and reviewing the video from that day, I worked on being less abrupt on the transition. Now I ease off brake pressure as I ease on lean angle. Nick Ienatsch in fact, is a proponent of trail braking for sport riders. http://www.cycleworld.com/2014/05/28/the-brake-light-initiative-treatise-on-motorcycle-control-using-your-braking-skills

OBX-RIDER
06-04-2016, 08:29 PM
I used to brake in a straight line, as taught in MSF, then flick the bike over. After a session with one of the now Yamaha Champions Riding School instructor, and reviewing the video from that day, I worked on being less abrupt on the transition. Now I ease off brake pressure as I ease on lean angle. Nick Ienatsch in fact, is a proponent of trail braking for sport riders. http://www.cycleworld.com/2014/05/28/the-brake-light-initiative-treatise-on-motorcycle-control-using-your-braking-skills

That's actually a better description of what I do ... :)

http://i130.photobucket.com/albums/p276/OBX-RIDER/zzzzzzzzzzzzzzz258264_1795019154914_6462074_o_zpsx rimm6ch.jpg (http://s130.photobucket.com/user/OBX-RIDER/media/zzzzzzzzzzzzzzz258264_1795019154914_6462074_o_zpsx rimm6ch.jpg.html)

I need a trackday ... or two ...

LoDownSinner
06-05-2016, 09:41 AM
I have to add a caveat. I watch a lot of Moto3/Moto2/MotoGP ... free practice/qualifying/race ... so I see a lot of really really good riders ... crash trail braking. Mebbe just a little too much brake ...
OR, possibly braking just a fraction too late?

NORTY
06-05-2016, 11:44 AM
Good stuff. I was a finish the braking then turn

Cornerspeed emphasizes that when braking the front fork is compressed ... and the bike turns easier and faster with the fork compressed. Yet the way I was doing it ... the fork is compressed... brakes released ... forks extend ... bike turned ... forks somewhat compressed ... boingo ... boingo ... Trail braking ... braking... compressed ... as you ease off brakes turn ... forks stay compressed ... not as much as braking but some.

I have to add a caveat. I watch a lot of Moto3/Moto2/MotoGP ... free practice/qualifying/race ... so I see a lot of really really good riders ... crash trail braking. Mebbe just a little too much brake ... like 41% when the cornering is using 60% ... so my brake/corner is more like totaling 90%. Ideally braking goes to zero as cornering comes to 100 or maybe 99%. With me braking is zero when cornering is mebbe 80% then I continue to 90-95%. I'm ok sliding the rear tire ... a little. When I slide the front tire it is either a) a mistake ie. I went off throttle momentarily or b) I am riding over my head ... :-|This was my thought also...

Upsetting the chassis has got to reduce available tire friction. And, as we know, the rider with the most tire friction can change speed and direction quicker than the other riders. (With all else being equal.)

NORTY
07-11-2016, 09:10 AM
Man, I have a vintage YZ400 that would love to come out there and do some desert racing! BRING IT!


And actually, I'm a firm believer that riding on dirt is one of the greatest preps for roadracing. It allows you to develop the confidence, reflexes and responses to be able to handle those times when the bike gets a little loose. This skill definitely makes for a more "well rounded" motorcyclist.
If you watch the really fast guys, you'll see that nearly every turn is taken in a light two-wheeled drift, kind of like on sand, but MUCH less. Being someone "who races to participate," I have no clue how they do it consistently...Some say, they "remove the overheated top layer of rubber" when they slide, exposing cooler rubber that offers more grip. (Hasn't become "greasy" yet.) While being in a 1 wheel drift doesn't bother me, a 2 wheel drift would have me nervous as hell. Scared too.