Don't forget to downshift

[jguarnieri]

Hi All,

2003 FXSTSI Springer.

I always look for safety tips on the web. A lot of tips mention the stopping power of the front brake which is 75% to 80% of a bikes stopping power.


I replaced my stock 1 piston fornt brake caliper with a 4 piston front brake caliper on my springer.


I practice hard breaking in a large parking lot and I use my front brake ONLY. My bike stays in a straight line and my rear end doesn't come around.

I will use the rear brake too, but very moderatley. I use both my front and rear brake in normal traffic, and slow speeds, but in a fast practice PANIC stop I use just my front brake.

What a lot of tips I have read forget to tell you is to DOWNSHIFT while you are breaking.

If you have to stop hard in a panic situation and you survive the stop, you dont want to be in 5th or 6th gear if you have to suddenly get out of harms way after your panic stop.

Don't get me wrong do use your rear break for normal riding. I'm just saying in a panic stop i try to think FRONT BREAK, FRONT BREAK, FRONT BREAK, DOWNSHIFT, DOWNSHIFT, DOWNSHIFT, CHECK YOUR MIRRORS, CHECK YOUR MIRRORS, CHECK YOUR MIRRORS.

To do all 3 in a real situation requires parking lot practice or deserted road practice.

My 2 cents.

John G

[hamyoo06]

Knowing the right gear to be in, especially in panic situations, is an art mastered only through experience.

I can't see why anyone would use the front brake only. You have two tires touching the road. Your stopping power comes from the friction between rubber and road. Two tires means more contact patch. Why not use both? The reason the front brake is responsible for most of the stopping is because, during braking, the vehicle weight shifts forward, putting more pressure on the front tire (or tires in a car). So your front tire has more friction than the rear, simply due to the weight transfer under hard braking. For this reason, you can squeeze harder on the front brakes than the rear brakes before breaking loose. But that is no reason to completely forfeit the contribution of the rear stopping power.

This is also why rear-wheel drive is superior to front-wheel drive under hard acceleration; in hard acceleration, the weight shifts to the back tire (tires) resulting in more grip in the back (and less in the front).

If AWD is done right, it can be superior to RWD in acceleration. The problem with AWD is the energy loss (read power loss) of the extra shafts and gears. Brakes on motorcycles suffer no such compromises.

I recommend using both.

[jguarnieri]

Originally Posted by hamyoo06

Knowing the right gear to be in, especially in panic situations, is an art mastered only through experience.

I can't see why anyone would use the front brake only. You have two tires touching the road. Your stopping power comes from the friction between rubber and road. Two tires means more contact patch. Why not use both? The reason the front brake is responsible for most of the stopping is because, during braking, the vehicle weight shifts forward, putting more pressure on the front tire (or tires in a car). So your front tire has more friction than the rear, simply due to the weight transfer under hard braking. For this reason, you can squeeze harder on the front brakes than the rear brakes before breaking loose. But that is no reason to completely forfeit the contribution of the rear stopping power.

This is also why rear-wheel drive is superior to front-wheel drive under hard acceleration; in hard acceleration, the weight shifts to the back tire (tires) resulting in more grip in the back (and less in the front).

If AWD is done right, it can be superior to RWD in acceleration. The problem with AWD is the energy loss (read power loss) of the extra shafts and gears. Brakes on motorcycles suffer no such compromises.

I recommend using both.

Thanks for your reply,


This is true.
>The reason the front brake is responsible for most of the stopping >is .because, during braking, the vehicle weight shifts forward, putting more >pressure on the front tire (or tires in a car).


I try to forget about the rear brake because in a panic stop I don't want to do a highside If the average rider gets on the rear break hard he will most likely do a highside or a lowside.

If the same average rider gets on the front break he will at least stop in a straight line You can apply the rear break of course but I feel in a panic stop most riders will over due the rear break and bring the ass end of the bike around, then more panic sets in and the rider releases the rear break "worst thing you can do but it is instinctive, and possibly do the dreaded highside.

As far as what gear you're in after down shifting, you're right practice but go for first gear all the way down, worst case your in 2nd gear thats better than 5th or 6th.

I have been in, "not quite a panic stop situation" ,but close, and I just used my front break I stoped in a perfect straight line, I have watched other riders rear ends start to come around on them in stops not nearly as close as the one I just mentioned.

This spring try it. You'll be surprised at how fast the bike will stop with the front break only.

Here is a google search I just found

Re: When to Use Rear Brake Only?

The heavier the bike and the lower the center of gravity, the more rear brake can be used. Also, with a passenger, more rear brakes can be used for smoother stopping and less front end dive.

A good rule... the engineers aren't stupid, the size for the brake is a good indicator of how hard it should be used. I beleive the rear brake surface area is less than 20% of the total braking surface.

When do I use only rear brake. At low speeds when trying to reduce the effects drivetrash lash at small throttle positions. I also mostly rear brake at low speed turns where the front brake can be grabby causing a loss of balance. Finally on loose surfaces I will favor the rear. For one reason, the rear tire is wider and therefore easier to control when sliding that the narrower front wheel.

For emergency stopping (I hate the term "panic stop". You never, ever panic on 2 wheels.) ... it's ALL front brake. Engine braking provides plenty of rear braking force... especailly on my BMW twin.

Thanks

[Jeffytune]

Wile I do agree to point what you are saying, I must point out the perils of downshifting to stop.

On a hard panic stop, and I will point to my own 2007 E-Glide, if you do a HARD, Panic style downshift to stop, The shock can overload the crank pin and shift the crank pins.

You will have stopped the bike, but now you will need an overhaul of the bottom end to fix the engine.

The key to a panic stop is to not panic, and to have practiced how you use your brakes to stop your bike before hand.

A calm mind, and a good plan that you have practiced will be your best hope of survival.

[YorkHogRider]

I believe what "J" is speaking of is when you grab a handfull of clutch and a handfull of front brake to come to a quick emergency stop. The importance of downshifting, without re-engaging the clutch, is paramount for just the reason "J" mentioned, getting the hell out of the way of what might not be stopping behind you.

[jguarnieri]

Originally Posted by YorkHogRider

I believe what "J" is speaking of is when you grab a handfull of clutch and a handfull of front brake to come to a quick emergency stop. The importance of downshifting, without re-engaging the clutch, is paramount for just the reason "J" mentioned, getting the hell out of the way of what might not be stopping behind you.

You got it.

The importance of downshifting, without re-engaging the clutch.

Thanks
John G

[Milehog]

Yessir, downshift while you slow down, not to slow down.

[jerry34208]

Well, this is coming along nicely. Good tips, good clarification. I like the advice and the reasoning. I'd add that we should practice emergency stops using both brakes for reasons already mentioned.

No surprise you can, with just the front brake, out brake other people. That's because they have not been practicing or you are way more gifted than they are.

Apply that skill with knowledge of physics also as explained in previous post. Try it on dusty roads, wet roads, sugar sand, try it and try it over and over. You will learn to use them both right up to the edge of their ability because you can increase your ability if you practice. Get good at learning the feel of each of the the tires beginning to lose traction. Get a feel for it on every type of surface you ride on. The tire has the best grip when it is skidding just a little bit. Learn to get it into that zone, maybe a little too far, and bring it back.

That being said I do agree with you that for many it may be better to focus on front brake only. On my SV1000S on clean dry smooth pavement it was pointless to use the back brake in hard braking as the bike was on the edge of a stoppie anyway. My Ultra and my FXD both keep the rear tire firmly on the ground (especially in less than perfect traction situations) so I think there is some stopping power to be used in the rear.

Master that, then include downshifting to be ready to go. I agree that you need to be ready to move once you have avoided the threat. Being in the correct gear is an advantage for sure.
Not arguing & I have no formal education on the matter, just tossing in my.02

[YankeeBob]

It's spelled "brake".