You guys will know this

[eddiekay]

After a mere 49 years in the saddle I've discovered that my front brake can work much better than I knew. It even works in a pretty tight turn without launching me off the seat ( I use the rear for that).
But...don't laugh....using it for the first time in a switchback downhill off camber park road, the bike seemed to wiggle and the wiggle felt like it was coming from the rear. No rear brake was being applied. Road was clean, rear tire was maybe 2lbs low. I mean...it was fun but I didnt know what to make of it. I'd like to correct it. Any opinions?

[Sirref]

so you were on the front brake when the rear wiggled?

if so then this makes sense, the front brake loads more weight on the front tire and takes that from the rear tire. So the rear becomes much lighter and more prone to wiggles and the like. The same happens in reverse when you get on the power

[eddiekay]

Sooo...really....is this mostly a matter of learning how hard to brake ( to correct it) or just enjoying the wiggle. The turn is very short...less than maybe 100 feet entry to exit...but downhill

[Ghostt]

Using the rear properly is sometimes a lost art, often use it went I'm just a little too fast in the turn, I apply very lightly, trailing the rear just enough, but not too much.

It takes a lot of practice, I'm sure the racers will agree, and also give more helpful tips.

I do believe that the MSF Advanced Rider Course teaches this along with other skills.

http://www.msf-campus.org/advancedridercourse.aspx

It's also a good idea to retake the course every few years, just to keep you trained, so to speak. Another benefit is it could save you some insurance money.

Advanced RiderCourse
Prerequisites: A valid motorcycle permit, license, or endorsement. Riders must provide their own street-legal and safe motorcycle.

A one-day course for riders with basic skills, this class provides more in-depth riding techniques and procedures than practiced in the BRC. The course consists of activities that emphasize personal risk management and self-assessment strategies, and on-cycle exercises with emphasis in cornering, braking and swerving. For permit holders, this course may be used as a license waiver course, if permitted by state regulations. Riders in this category would be required to successfully complete a knowledge and skill test. For riders already possessing a license or endorsement, the testing portions of the course are optional.
Even if you’ve been riding for some time, there’s always something new to learn. Increasing numbers of seasoned riders are flocking to the half-day Experienced RiderCourse to hone their skills and fine-tune the mental skills needed for survival in traffic.

You’ll discuss with your peers how to balance the mental and physical aspects of safe riding, manage risk, increase visibility and optimize your lane position. The Experienced RiderCourse also covers protective gear, rider responsibility, motorcycle inpection and care, the effects of alcohol and other drugs on riding, and includes an optional skill evaluation and knowledge test.
Using your own motorcycle and helmet, you’ll put into practice the techniques of managing traction, stopping quickly, cornering and swerving.

Find a RiderCourse near you.

[Sirref]

Originally Posted by eddiekay

Sooo...really....is this mostly a matter of learning how hard to brake ( to correct it) or just enjoying the wiggle. The turn is very short...less than maybe 100 feet entry to exit...but downhill

uhh, I can't recommend that as a good time to brake if you can avoid it

the front is already loaded so your braking limit is much lower before you lose the front (still much higher than most people think it is)

[Ghostt]

Originally Posted by Sirref

uhh, I can't recommend that as a good time to brake if you can avoid it

the front is already loaded so your braking limit is much lower before you lose the front (still much higher than most people think it is)

Very very true, I just barely use the rear, trialling it so to speak, I don't normally recommend it, unless you REALLY KNOW WHAT YOUR DOING!! Low speed practicing in a big empty parking lot,

[adouglas]

You're threshold braking... AFAIK nothing to "correct" here, just don't be stupid and to something abrupt -- like chop the throttle -- when the rear loses traction (i.e. wiggles). That way lies a highside. From your description you're getting pretty close.

Watch MotoGP. These guys back it in to every hard braking corner, with the rear barely skimming the pavement and moving kind of sideways.

So what you're trying to correct is that unnerving feeling of the rear breaking loose, right? Therefore you want more weight on the rear, and that means a less pronounced weight transfer to the front.

Better IMHO to brake harder before the corner and trail brake into it so the rear isn't floating while you're turning. Your speed into the corner will be lower but the bike will be more settled and you'll be able to drive out harder.

If you also get off the bike some it'll be more upright, which gives you more available traction. Remember the pie... have 100 points of combined braking, turning and acceleration. Use fewer points leaning/turning and you have more available for the other two.

[eddiekay]

ok....let me get into a long description:
I used to enter these tiny turns by downshifting....just before the lean.
Wheel hops, engine scxreams...it was Ok.
My goal was to let the engine gradually slow the bike thru the turn .
When I could see a straight line out, I'd upshift and WOT
ANDY...just saw your reply....I'm taking about those roads i took you guys on....
This year I'm using the front brake to slow down. But...I'm braking into the turn as well because i feel like I'm still going too fast when I start to lean. And I got to wonder if what's really going on is that I just have to get some confidence in my tires. I mean really....scraping my toes scares me but...the bike is not sliding sideways. These are where I'm not going 35mph. Like a really fast gymkhana.

[eddiekay]

ok...the answer may be obvious to you but...
If i approach in 3
brake down to where I'm out of the power band
and then lean
WHEN SHOULD THE DOWNSHIFT TO 2 HAPPEN OR HAVE HAPPENED ?
WHEN SHOULD THE UPSHIFT TO 3 HAPPEN
OR
SINCE THESE ARE SMALL SHORT TURNS, SHOULD I BE JUST LUGGING THRU IN 3.

[adouglas]

The goal is to be smooth. When the bike herks and jerks, it's harder to control. So think about that when you consider the following questions:

What happens to the chassis when you downshift all the way and dump the clutch to slow down?

What do you think would happen if you were to brake while downshifting to your target gear, let the clutch out more gradually, trail brake into the turn and use a smooth and continuous roll on?

What happens to the bike if you enter at a high rate of speed and need to shed velocity in a hurry?

What do you think would happen if you were to reduce your speed sooner and smoothly accelerate through the turn?

What slows you down faster: heavy braking or relying on the engine?

Does being more stable allow you to carry more speed?

If you could get the bike sorted and stable before you turn, do you think that would help you be smoother?

Do you think you would need to suddenly pin it at the exit if you were able to crack the throttle open earlier and roll it on smoothly through the turn?

What's faster: Coasting through the turn until you see daylight and then hitting WOT, or smoothly rolling on from a lower speed?

What's more stable: Coasting through and letting the bike slow down then whacking the throttle open, or smoothly rolling on?

--------

So what do your answers tell you about when to shift?

[Panda]

Everyone knows that braking in a turn instantly leads to a fiery explosion. Keith Code says so!

[adouglas]

Ha. He doesn't, really... but it sure seems that way.

Contrast with other writers who overemphasize trail braking as the answer to everything. There's a time and a place for both approaches.

I think Code's seeming aversion to trail braking comes from his emphasis on the traction pie. If you're at the cornering limit there's nothing left for braking... and yeah, if you hit the brakes in that situation you will indeed tuck the front and do some pavement surfing.

In my admittedly limited experience on the track, I've found trail braking to be a useful tool for stabilizing the bike, but it's not about serious deceleration. If you need to slow down A LOT while turning to make the corner, you've charged it in the first place.

[csmith12]

Originally Posted by adouglas

If you need to slow down A LOT while turning to make the corner, you've charged it in the first place.

[Panda]

Originally Posted by adouglas

Contrast with other writers who overemphasize trail braking as the answer to everything. There's a time and a place for both approaches.

If I had to speculate (and I am) I think some people overemphasize trail braking because Keith Code ostensibly vociferously opposes it. He's one of the biggest voices in the community and some of the things he professes in his books as absolutes about braking are wrong.

He corrects or appears to soften his views on trail braking in some of his articles but that legacy of his books remains. (Reference: any thread about braking.)

Ultimately though I agree with you. There's a time and a place for both.

/threadjack off

Sorry Eddie.

[eddiekay]

DAN and ANDY...spend less time on those darn racetracks and in Brooklyn and come to Harriman Park with me....I'm goinbg saturday to try some of what andy's suggesting.

[Panda]

Something that might also contribute to this is gripping the bars too tightly.

I'm in philly this weekend otherwise that sounds good. I've only made it up to Harriman once this year. You should hit up the track. I think you'd like it.

[Motofool]

Originally Posted by eddiekay

After a mere 49 years in the saddle I've discovered that my front brake can work much better than I knew........... Any opinions?

I don't have much to say that you don't know after 49 years in the saddle.
I would like to help you understand the Physics behind what you have explained.

Normally, three things are perfectly aligned: front contact patch, center of mass (bike plus you) and rear patch.

Whenever we are decelerating, regardless the brake or engine-braking effect that is applied, the center of mass is trying to move ahead of the front contact patch.
The friction of the rear patch is preventing that from happening.
Any minimum steering input from you will make the C of M to swing one way or the other, as the friction of the rear contact patch becomes marginal.

Regarding leaning and breaking while going downhill:
The front contact patch is being overloaded and is close to the limit of total traction (longitudinal and transversal).
Loosing the front is easier than in horizontal curve and moderate acceleration conditions.

[csmith12]

Originally Posted by eddiekay

After a mere 49 years in the saddle I've discovered that my front brake can work much better than I knew. It even works in a pretty tight turn without launching me off the seat ( I use the rear for that).
But...don't laugh....using it for the first time in a switchback downhill off camber park road, the bike seemed to wiggle and the wiggle felt like it was coming from the rear. No rear brake was being applied. Road was clean, rear tire was maybe 2lbs low. I mean...it was fun but I didnt know what to make of it. I'd like to correct it. Any opinions?

Naw... something else is different too, it's not ONLY the brakes. Downhill off camber corners pose a challenge to the normal throttle control rule unless adjustments are made to entry speed and trailing into the corner adds yet even more challenge.

Basics;

Set a good entry speed where you can be rolling on the throttle at a good time in the corner. This could be different than other corners due to the downhill/camber nature of the road.

If you are trailing in, with a decent amount of lean, and much weight on the front... if you're tight on the bars can start little slides from the rear.

Line? Can you adjust the line to minimize the off camber exposure? ie late apex with a quicker flick?

[csmith12]

More stuff...

I applaud you for making the change in trusting in your front brake. The nature of front braking makes the front more twitchy (even heavy) feeling vs rear only braking. It's just the nature of the beast. It's super easy to be tight on the bars at this time and very subtle inputs to the bars are felt via your bum in the rear end of the bike.

It takes some adjustment to get used too, but once you get yourself wrapped around it, it aint no big deal. I had to make this shift myself coming from my cruiser background. You know.... I used the rear brake most of the time on my HD soooo many years ago. lol

Good luck and happy riding.

[cbinker]

sounds like fun! love it when the back end is wagging going into turns!

[eddiekay]

CS and Panda....yup...youse guys mentioned it and i remembered it....I was squeezing' them grips like lemons on that section I'm talking about and while i thought nothing of the effect, I DO remember doing it and reminding myself to loosen up.Andy and Moto....excellent explain of the physics and geometry. Nice stick figures in the link!
OK...I think I understand what's happening on that particular section now. I believe I might try entering slower and coming out faster because the way in is much tighter than the way out. What has spooked me is that the end of the turn feels steeper than the beginning ....How can I describe it ?......Like that Mullholland turn everybody crashes on,,,, 1/3 the radius, twices as steep. Yeah, it's fun, wheel wiggles and all.
Thanks for so much help guys.

[adouglas]

Remember that the downhill is causing the bike to accelerate all by itself, but it's not weighting the rear like throttle application will.

That's why you need to go into downhill corners slower than you would go into the same corner if it was flat.

The off-camber will also reduce your available lean, which means you have less leeway with speed.

[eddiekay]

It's actually very helpful to read you all explain what's happening as I can trace back most of what's been explained to something I've experienced yet didn't think about why or how I was experiencing it, as i was experiencing it.
I'm not really trying to get faster but once in a while I realize that something could've been done better ( faster?) with the bike if I knew how to get the bike to do what it can. So..this stuff is helpful. Thanks again.

[adouglas]

Skills to go fast + not going fast = greater margin of safety.

WIN



I was thinking about your scenario a bit further. Downhill, off-camber, sharp turn... sounds a lot like Turn 4 at Thompson.

That happens to be the turn where I discovered what trail braking actually does for you.

Here's how I approach that particular corner:

- Blast up the straight, on throttle

- Off throttle and on brake hard-ish (no coasting), downshift to 2nd gear while this happens. Always on the brake. Let out the clutch smoothly - no jerks. Bike is already in gear before the turn, and already slowed.

- Tip in, looking for very late apex. Still on the front brake but just a little bit... just dragging, not trying to slow down. That's trail braking. What this does is settle the chassis... makes it feel a LOT more stable.

- Feed in throttle very slowly as the brake comes off. Slowly because it's downhill and gravity is helping you. At the apex with the bike standing back up, roll on more aggressively.


What's happening with the throttle is something called "maintenance throttle." It's just a little bit, to keep the bike from "falling over" as you tip it in. If you've ever had that feeling of the bike wanting to fall out from under you going around a slow corner, it's because you weren't on the power at all.

When you lean a tire over, its effective circumference is less. It's like you're suddenly riding on 14 inch wheels instead of 17 inch wheels. The bike will slow all by itself simply because of this. Maintenance throttle counteracts this effect and keeps the bike from wanting to fall further.

In practice, what you're doing is cracking the throttle open and increasing it very, very slowly... that's the maintenance part... then when you can, you roll on faster. But never whack hard. Always smooooooooth....

[eddiekay]

After all the info I got last night i tried to understand this on GoogEarth.
The arc of this 180 is about 196', the drop in elevation is a bit more than 30', the radius calculates to about 55' but,,,in fact way way less and it goes off camber about 30' in....till the end. I understand 1 part of my error.....the approach is a straight 700' that drops 30' and i'm simply (maybe) going in too fast and too close to center, causing me to correct.......I do that all the time, I lean in too much because I start the turns wrong....too close to center when there is no oncoming....will apply suggestions tomorrow.

[csmith12]

If you want to mess up a corner royally.... blow your turn in point or pick a bad one. How do you know if you have a good turn in point and line? What is the criteria you can judge it?

[eddiekay]

Chris....street guys dont do this stuff, the first time i read Keith's book I thought it had noting to do with what I was doing...I think it does have to do with what I'm doing now. Motofool made his point well "center of mass chasing the contact patch" OK...so we'll see tomorrow ?

[csmith12]

There are no less than 100 points in the TOTW2 book that can be applied to street riding. Sure, it's targeted to track/performance riders but I find value no matter the wrapper. In fact, in the TOTW2 movie, there are many segments where a NON sport bike is filmed with a rider applying a skill on public streets.

Watch it when you get the time, the plot sucks and the characters are dry... lol but it's totally worth the time.

[adouglas]

Originally Posted by csmith12

In fact, in the TOTW2 movie, there are many segments where a NON sport bike is filmed with a rider applying a skill on public streets.

Watch it when you get the time, the plot sucks and the characters are dry....

Except for @Misti. She rocks.

[csmith12]

Originally Posted by eddiekay

Chris....street guys dont do this stuff, the first time i read Keith's book I thought it had nothing to do with what I was doing...

Link to original page on YouTube.

Originally Posted by adouglas

Except for @Misti. She rocks.

Some things go without saying.

[csmith12]

Eddie,

Here is your answer per CSS application, ALL 100% applicable to street riding and relative to your situation. For a clue... your corner(s) concerns (downhill/camber) fall under "surface". Tight on the bars (SR) falls under steering ie unwanted or unneeded inputs and your exploration in front braking may cause instabilities as such input warrants.

Link to original page on YouTube.

So after reviewing this and your recollection of the corners in question, what are you doing that is causing your bike's instability?

[csmith12]

Originally Posted by adouglas

What's happening with the throttle is something called "maintenance throttle." It's just a little bit, to keep the bike from "falling over" as you tip it in. If you've ever had that feeling of the bike wanting to fall out from under you going around a slow corner, it's because you weren't on the power at all.

Sometime soon, Imma challenge you to nearly remove almost ALL "maintenance throttle" from your riding. Sure there are corners or sections of road where a slight roll off or pause in throttle is warranted to complete a steering action or set entry speed (call it what you will) but the secret is to know when and why. To not derail this thread and keep things simple, brakes are for scrubbing speed and setting entry speed. To use them for 99.9% any other reason is to address a symptom vs addressing the cause of the problem in the first place.

Originally Posted by adouglas

When you lean a tire over, its effective circumference is less. It's like you're suddenly riding on 14 inch wheels instead of 17 inch wheels. The bike will slow all by itself simply because of this. Maintenance throttle counteracts this effect and keeps the bike from wanting to fall further.

There is so much more to this.... True! Your wheel is smaller at the edge of the tire vs the center. What does that do to your rpms? If you suddenly raise 375rpms without throttle, what is the engine doing to the speed of the bike? Is that condition helping the stability of the bike midcorner?

[Motofool]

Originally Posted by eddiekay

Chris....Motofool made his point well "center of mass chasing the contact patch" OK...so we'll see tomorrow ?

I believe that I should have clarified that we were looking to the bike from above.
When applying front brake hard, the Center of Mass tries swinging laterally (which is its easiest way to move forward of the contact patch that is resisting the forward movement), inducing a fishtail movement (sometimes a small side-to-side oscillation, sometimes a one-side-slip that reaches some appreciable angle).

Something similar happens to airplanes with two main wheels at front (tail-draggers).
Once the rear little wheel is up in the air, the airplane becomes harder to keep on a straight trajectory as it tends to fish-tail, harder when landing and applying brakes.

Another example is what happens when we are pushing a heavily loaded wheelbarrow and the tire encounters a big rock.

When you see a Moto GP racer braking with the rear tire in the air, he is using the handlebar to keep the balance, which only means to keep that Center of Mass perfecly aligned with the front contact patch.
With minute inputs onto that handlebar, he is slightly moving that contact patch side to side as the C of M tries to swing around.

Same happens when we try balancing an upturned broomstick on the palm of our hand: we slightly move the point of support horizontally around, following the natural tendency of the broom to fall.
If we delay the needed reaction, the deviation between C of M and pivot point becomes too big and almost impossible to correct.
That is known in Physics as an inverted pendulum, which is inherently unstable and must be actively balanced in order to remain upright.

Those riders master two important things: a fine sense of tri-dimensional balance (can feel minimum deviations) and quick but moderate reactions (input exactly the necessary feedback to keep total control).

[csmith12]

Dood! That wheelbarrow example is spot on how a little bit of input can go a long way.

[eddiekay]

Well....
I went to my favorite down hill off camber place. Entered the turn slower....which eliminated the need to correct and pray simultaneously but let me lean over a bit more and was able to get out noticeably quicker. I dont know if i got thru the section any faster but it was more fun....twitch-less, without a wiggle. I would guess that ...if i were clocking this....the time i saved by going as fast as i could as far as i could was wasted by the time i spent correcting the turn that I went into too fast.
Any how....y'all gave me workable advice. Thank you.

[csmith12]

[Motofool]

[adouglas]

Now that you know how good it feels, come on up to Thompson on September 27 and do the FREE "try the track" session. All you have to do is get there.

Sorry, no loafers.

[Panda]

Originally Posted by adouglas

Now that you know how good it feels, come on up to Thompson on September 27 and do the FREE "try the track" session. All you have to do is get there.

Sorry, no loafers.

+1 this.

Eddie get thee to a track. You'll love it.

[alex.s]

2 crashes ago, i slid out my rear while i was turning in hard on the front brake. the rear let go as i started to let off the front as the turn-in was finishing. hit my head on the curb. ****in curb.