Back Brake - You better stop me .....

oh yea..an trust yoda to take a relatively easy to understand post, make it techinical, and confuse the fark outta all of us...geez ud think this was a "techinical" forum...
neka

would an expert please correct me, not some newbie fresh off his training wheels. rear brakes - flakey, 70,000km and 3 sets of fronts and still on the original rear pads? you dont use them enough..

so i barely touch the fronts unless i absolutely have to, the rears get used in the majority of the time.

maybe some people need to ride their bikes.... like the manufacturer intended.


.

ok..where do i start??
am i a "newbie" ?..only been riding for 8 yrs on road,5 of them on hi performance,hi power bikes...(zx6r,vtr1000,cbr929, not to mention the zx9r,R1,fzr1000,gix 750 etc that ive ridden, oh an the might ER-5-boy did i cane that thing!!)...so i guess i got a right to stick my 5c in...

rear brakes..hm sum love em, sum hate em..i been told by many racers "dont use em, there only for decoration"..i DO use them , however not for stopping in a hurry...ever seen wot happens wen u jump on a rear brake?? id rather pay $1k for a set of discs, than my life by locking a rear & gettin thrown...but hey,personal choice, and thats just me....barely touch the fronts...mwahahaha....
ride it like the manufacturer intended?? using only the rear brakes?? mwahahaha is that really dan fishing for a bite??haha good work, change ur name back & stop being a smart ass danno...surely im the only 1 silly enuf to bite??
..as the manufacturer intended...i kno of a few guys on here i can vouch for who DO ride that way..i notice ur in nsw...
go for a ride with Dave,Phil,Tim and see whos braking style works best... come to SA, and see whos braking system works with Jamie,myself, and Piggy....hell if ur in melb, go for a ride wiv mario,old ian,rob...i believe there not entirely slouches....ok..ive had enuf..im goin now..
fark u gave me a good laugh tho..hehe well done..
neka

i just had a look to see who "davezx9" is..an its the dave i refered to in my reply!!...dave..u been smoking the shit again?? or u just trying to start shit? i wouldnt of thought u were silly enuf to say "i only use front when i have to"...unless uve had a big fall lately?? hows ya head dude?? feel it & see if u got ne lumps on it...maybe u need to pick up dude? that mite let ya get enuf blood flow to ur brain that u can think str8?? or maybe ..nah i cant think of ne other excuses for ur post, unless u meant front where u said rear??.dude..wot goin on??
nekSTaR

neka - maybe if you stopped fucking your hand long enough you'd realise it was me who posted that and not dan.

yeah, like the manufacturer intended... no front brakes.. neka, if you werent sure, that means properly. im not the only one who's used that phrase either.

neka - maybe if you stopped fucking your hand long enough you'd realise it was me who posted that and not dan.

yeah, like the manufacturer intended... no front brakes.. neka, if you werent sure, that means properly. im not the only one who's used that phrase either.

ok lets have a personal barrage if insults!!..there goes your christmas card.....

now...as the manufacturer intended huh...ok..so if the front brakes r only there 4 decoration mate, tell me this...

Why do they put 2 big ass discs (300mm+), floating/semi floating, with 2/3 pot , mostly now radially mounted callipers on the front....but yet they put one pissy (200mm ish) non floating disc, with a single pot calliper on the rear??

also answer me this...Rossi et al back there bikes into corners (arguable whether its quicker round a track, but hell more interesting to watch) , and they end up with the rear wheel often waving in the air,or close to it....now im pretty sure rossi has a vague idea how to ride (he only won 5 world tittles, but fuk ne1 can do that, even mick doohan!!)...
thats cool tho, ill tell mick next time i see him he was doin it all wrong for all thise years, imagine how many races he woulda won if he only used his rear brakes!!

ill b keepin my eye out in AMCN at the back for "crazy daves braking course" and ill be sure to email vale,aussie troy,edwards, sete etc & they can come & learn how to ride properly....
maybe thats why it took kwaka so long to find a podium? they werent aware of this technique till recently?? insider info mate?? thats not fair....

so u think im taking the piss?? hell no...not me

ok ive had enuf of this game...i win...
neka.
p.s. u smell funny too!

And the win goes to NEKA in straight sets.
Well done lad. You can probably take your training wheels off now.

Fark you're funny Neka!! Yeah, you win hands down. Some good points made.

Do you really send Christmas cards???

Hey I didnt drag this post away from Quarkz back brake sping drama to have you bloody kids make a game of Activision Tennis out
of it. "You'll go to Your Room young Personages...."

There has been some really Great Opinions, Suggestions & Tecniques put forward & I have tried to embrace them for what they are just peoples thoughts being smashed through a typewriter n a phone line(mostly) None of its Gospel or "How Toos".

I have read a lot of my experiences in quite a few posts. The more serious stuff like this i read, the more i want to learn. So thanks to all contributors, please keep it coming.

The day i stop learning an trying to be better myself is the day you can Put the Bike n me in a box & throw Shite at us both.
Cheers Brett

what the.. i hit the front brakes mid corner and my bike does NOT stand up - rather, it holds its line, and thats how i like it. its a matter of suspension - if i'm wrong, would an expert please correct me, not some newbie fresh off his training wheels. my bike DID stand up under front brakes thru corners, but the suspension was like, totally out of whack, and after a lot of guesswork and adjusting, i think ive got it close to being perfect.

You're right, it is a matter of suspension. However, any bike with a telescopic fork front end will stand up in a corner if you use the front brakes. You may not notice it standing up, but this will be hidden by the fact that you are running wide.

I may me wrong with my theory here, but I'm sure someone will correct me.
When you have the bike on a lean, and you are half way through, let's say a left hander, your left fork will be compressed more than your right fork. When you pull the front brakes on, pressure from the calipers is applied to both discs evenly. As a result of applying your front brakes, weight is moved forward, with you trasferring that weight evenly through the bars and into the forks. This weight transfer causes the forks to compress and as the right fork is less compressed than the left fork, it is softer and will travel further so as to align itself with the left fork.
As a result of this extra travel, the bike will stand up. Maybe only slightly, maybe a lot, depending on how hard you've squeezed the brakes.

If you've squeezed the brakes hard enough, the bike will stand all the way up (which, as I think Ian has said before also has something to do with the forces acting on the wheel, but I don't understand all the gibberish), or if you've given a gentle squeeze, the bike will simply run wide.

Maybe I'm wrong, but that's how I've always seen it.

I do agree on one thing tho. If you are running wide in a corner, a little pressure on the rear brake will help you to tighten your line, but so will easing on the throttle a little. The way i see it, the rear tyre has enough to do, trying to create enough friction for you to stay on the bike. Asking it to fortget about that and have it slow you down is asking for trouble.

If it comes between using the rear brake, and rolling on the throttle, gimme the throttle any day.

I have read a lot of my experiences in quite a few posts. The more serious stuff like this i read, the more i want to learn. So thanks to all contributors, please keep it coming. The day i stop learning an trying to be better myself is the day you can Put the Bike n me in a box & throw Shite at us both. Cheers Brett

we (us members) aim to please....
Brett
seriously though, I agree with you re the learning
After more than 30 years of being on bikes, I am still gaining knowledge and info about 'em, I ask questions and I listen to those who know more.
If I am asked my opinion I give it (and yes sometimes I don't have the answer or the correct one)

The problem with bikes, is that sometimes you have to get a bit technical
to understand what the pharrk they are all about, to enjoy 'em more
and to ride 'em better......and some don't appreciate that

As I say in all my welcome messages to newbies...ask!

great thread btw...should be more of 'em


cheers

The effect of wieght transfer on suspension geometry is fuck all. The point of a good suspension set up is to cope with all this.

Matt
I have read and re-read your post, coz you confuse me somewhat.
What you said, appears to me to be a contradiction.
A good suspension setup will cope with weight transfer (or weight) on a bike
I absolutely agree with that.
But weight transfer or weight does affect a bikes handling and you have to know how to adjust the suspension, so that effect is minimized. I can't see how you can say weight transfer does not affect the suspension geometry when all the schools I have attended (HART and Superbikes as examples) have demonstrated that it does.
As I see it, the challenge is to minimize the effect of the change
(which is what DaveZX9r is at in his post)


cheers

I aint no Valentino Rossi, but here's my opinion.

neither am i..im better

According to what i've heard Rossi can actually ride straight without falling off. But according to everybody u keep falling off neka.

. sanipp .. So thanks to all contributors, please keep it coming. The day i stop learning an trying to be better myself is the day you can Put the Bike n me in a box & throw Shite at us both. Cheers Brett

an another sanipp here
.... I am still gaining knowledge and info about 'em, I ask questions and I listen to those who know more. If I am asked my opinion I give it (and yes sometimes I don't have the answer or the correct one)
The problem with bikes, is that sometimes you have to get a bit technical
to understand what the pharrk they are all about, to enjoy 'em more
and to ride 'em better......and some don't appreciate that
great thread btw should be more of 'em
cheers

Thanks Ian your comments are much appreciated (especially the Technical ones), the difficulty with any Technical answer is thats its often too easy to over complicate it or get to a point where we unknowingly contradict ourselves.

Keep em coming folks lots of Talented, Fast, Safe, Experienced riders out there yet to share your wisdom with me/us ....
ya greedy begga's .....
can't take it with you and may Actually save someones life.
Cheers Brett

The effect of wieght transfer on suspension geometry is fuck all. The point of a good suspension set up is to cope with all this.

But weight transfer or weight does affect a bikes handling and you have to know how to adjust the suspension. I can't see how you can say weight transfer does not affect the suspension geometry when all the schools I have attended have demonstrated that it does.
As I see it, the challenge is to minimize the effect of the change

Ok, for those who can't read what was actually written, I'll spell it out a bit clearer. It could be long,but we'll see how we go.
Now remember this is a thread regarding back brakes and how much to use, Not suspension setup.

Firstly; A good suspension set up will cope with any reasonable input that the bike receives. Yes, weight transfer will move the weight forward, but the effect this has on the suspension geometry are all good for cornering. The front dives wich increases the head/fork angle. This WILL (100%) encourage the bike to turn harder and tighter, no exeptions at all.

Secondly; Any of the schools, HART, Stay Upright, Aus Superbike school, and even Kieth Code's own books explain that a tyre only has 'X' amount of grip. Now consider the following:

1-A bike that is travelling in a straight line has about a 51/49% split front to back. Corner with no braking at all and the load split remains the same within 1/2% or so.
2- When a vehicle (car, bike, boat, plane) corners, you are basically trying to redirect momentum. This means that the grip required by both wheels increases.
3-When you are slowing the wieght split shifts forward, up to 80/20 when still under control,

This all means that the front tyre enters a corner having a lot more load on it than the rear. As a result the front will not take as tight a line as the rear, and it will 'push'. This IS NOT a result of geometry changes. Remember that geometry does change, but for the better. However the changes are not always great enough to overcome the increased demands the front has to deal with.

So as I wrote, weight transfer does not effect suspension geomtry. This should probably read, "does not effect supension set up adversly."
I did not say weight tranfers didn't effect handling as I was mis-quoted.

Hit the brakes and you run wide, a little or a lot. But the explanation lies in weight and force vectors, NOT suspension geometry. If you can remember back to when you were a kid, what happened whem you hit the brakes on your push bike? It ran wide, particlarlty using the front brake. Now pushies (excluding mtb's) don't have suspension, so it cant be changes in geometry that make it run wide, can it???

The answer- A tyre has only so much grip. If you are hooking along into a corner, chances are you are using close to all the grip a tyre has. Grip is limited by the friction or restitance it has against the road surface versus the load or enery being applied to the tyre. If the force is equal or less than the grip supplied, the tyre will hold it's line. If the force is greater that the grip, it will start to slide and run wide. If it way to much force, the tyre will let go and the front will tuck, if it's just too much, you get a gentle float into the corner.

Ignore GP or any racers really and think about what you see when you follow one of our quicker Vic members (Mario, Rob, Ron), into corner. I only picked on these three as I have riden behind all these three quickly in both wet and dry. As they enter a corner, the fron t wheel is doing the bulk of the work. It naturally runs wider than the rear, but only slightly as the wider rear tyre plays acouple of tricks that I won't even attempt to explain here. If you look at a bike similar width front and rears, or even a car, you can see it as plain as day when you look carefully.
Mid corner when you have a neutral throttle and steady speed, both wheels are doing the same.
Just pass mid corner when you feed in the power, the back difts or walks wider. Keith Code clearly explains this due to weight transfer shifting toward the rear, and in turn asking it to do more work. (for another thread, KC explains that modern bikes with huge rears need to be accelerated out of corners to cerate enough weight trans fer to give the rear tyre enough contact preasuure to grip properly, think about real working 4wd with their skinny little tyres)

In addition, too much load on a tyre makes it push, and not enough means that it doesn't get pressed into the road hard enough. It all about balance.
Most homolgation type bikes, ie. Zx6/7/10's run too wider a tyre for general riding, but the need these when pulling hard out off corners on effectively one wheel. If you use the formula (Ian, I know your good at formulas) to work out potential grip offer by tyres, you notice that fron and rear is pretty much identical front to back. It' the relationship between width, cross sectional profile, and the wieght likely to be applied to it.

So in conclussion, weight transfers effects handling. The suspension changes cause by weight transfer help handlind. But toomuch weight on a tyre will easily overwhelm it's grip and make it run wide.

For the newbies, the learn to ride book gives you the best piece of advise of all. Do all of your slowing down in a straight line. I feel yopu can experiment to see what is beat for you. And keep experimenting from time to time as your preference may well change as you skills improve.


I hope it's been done with clear enough launguage for everybody to be able to follow.

If your bored of the thread, I understand, but somethings need to be clarified so we can all benefit.
ps. this post is so bloody long I'm not gonna bother trying to fix my typos.

"If you use the formula (Ian, I know your good at formulas) to work out potential grip offer by tyres, you notice that fron and rear is pretty much identical front to back. It' the relationship between width, cross sectional profile, and the wieght likely to be applied to it."

thanks Matt..
good post
and for those who want to see a bit more of this
the article in the latest TwoWheels actually shows (in a graph)
the result of what Matt is talking about...
and
you all might have noticed that a post or thread on the effects of braking
cannot be considered in isolation, from the effects of handling and suspension (and rider inputs to the bike as well)


cheers