Rear tire losing traction when braking hard

[PcH]

Hi all. My recent months of riding I've experienced my back tire completely losing traction and causing my bike to slide (scary as ****) when I have to brake hard. I've visually inspected the tires over and over and there isn't any fluid on it/nails/etc. This will only happen when braking hard in a straight line. As soon as I feel the tire slip/sometimes even hear the tire squeal, I'll let off the brakes real fast and go back on them (like I was taught in the MSF I believe). What could be wrong here? Thanks.

 

[greg]

use the front brake and only a little rear. as you slow down weight is transferred to the front, reducing rear traction

for slow speed stuff you can get away with just using the rear

n.b. progressively and firmly apply the front, don't grab it, or you can lock the front up and lose it (especially in the wet)

 

[Hellgate]

You're simply using too much rear brake. Try so braking drills to get better. You want braking to become a reflex not a thought process.

Sent from my MB508 using Tapatalk

 

[PcH]

I always use both brakes. Braking drills aren't a bad idea. Haven't done those since my previous motorcycle.

 

[DownrangeFuture]

Yep, too much rear brake. I don't even bother with the rear in an emergency situation. I'm sure flaming will ensue, but I just don't think it's a great idea. Modern front brakes probably provide on the order of 90% or more of your braking. Learning to engine brake while emergency braking will probably provide more stopping power than using the rear, and you aren't as likely to lock the rear wheel if you do it right.

The only way to lock it, is to not practice and freak so you jump down way too many gears. Plus learning how to do that means if you have to start going again quickly, the bike is already in gear, just twist the throttle.

Anyway, I think the risks of locking the back tire at high speed or a high manuver situation, outweigh the benefits to stopping distance in using the back brake.

From 30mph, I was stopping in 18 feet with both brakes, 19 feet with just the front, and 15 feet using just the front and engine braking. And I didn't lock the rear 2 out of 3 times and go over 20 feet with engine braking versus front and rear.

Just my 2 cents. The MSF isn't wrong. But I think riders should graduate to front/engine when their skills are up to it.

 

[Zargof]

As soon as I feel the tire slip/sometimes even hear the tire squeal, I'll let off the brakes real fast and go back on them (like I was taught in the MSF I believe).

When you lock your rear tire on a solid surface you are supposed to keep it locked and ride it out. Releasing the rear has the potential to cause a high side according to MSF. You release a front tire lock up.

 

[PcH]

When you lock your rear tire on a solid surface you are supposed to keep it locked and ride it out. Releasing the rear has the potential to cause a high side according to MSF. You release a front tire lock up.

I had a feeling what I was thinking was reverse/wrong. Do you have a link or source for this?

 

[Squiz]

Yup, excessive rear brake indeed. To be honest, I rarely touch mine as I use my fronts 99% and never have any issues. :thumbup:

 

[Red Wazp]

When you lock your rear tire on a solid surface you are supposed to keep it locked and ride it out. Releasing the rear has the potential to cause a high side according to MSF. You release a front tire lock up.

You keep the rear locked up on the FZ6 and most likely you will go down. I found the 6 was really hard to use the rear brake when braking hard without lock up.

What really helped me was to move the foot brake lever down a few notches on the shaft. Made a huge improvement in my hard emergency braking with lots of practice. But as Reg Pridmore taught us in his Class, the front brake is your friend.

ABS would be our friend IF only we could have it in the states

 

[greg]

I had a feeling what I was thinking was reverse/wrong. Do you have a link or source for this?

I think the basic theory is the rear loses traction, continues spinning, and slides sideways, it then regrips and throws the bike up

[ame=http://www.youtube.com/watch?v=DOMcFEC4cBA]YouTube - Motorcycle Safety - Protective gear in action[/ame]

 

[Erci]

Zargof is 100% correct. Front brake lock-up calls for release and reapply approach. Rear brake lock-up calls for staying on the brake until you come to full stop. That's the MSF approach.
In actual application, if the bike is traveling in a perfectly straight line while the rear tire is skidding, releasing rear brake will not cause a high-side. The more the rear steps out when it's skidding, the higher the likelihood of a high-side when rear brake is released.
Unless you're very good and know exactly what your bike is doing, you are better off keeping the rear brake locked up until you come to a full stop, but it would be even better to practice braking often and not lock up the rear in the first place.

 

[PcH]

Zargof is 100% correct. Front brake lock-up calls for release and reapply approach. Rear brake lock-up calls for staying on the brake until you come to full stop. That's the MSF approach.
In actual application, if the bike is traveling in a perfectly straight line while the rear tire is skidding, releasing rear brake will not cause a high-side. The more the rear steps out when it's skidding, the higher the likelihood of a high-side when rear brake is released.
Unless you're very good and know exactly what your bike is doing, you are better off keeping the rear brake locked up until you come to a full stop, but it would be even better to practice braking often and not lock up the rear in the first place.

The bike was slowly turning sideways. I felt like keeping on the brakes in the moment would've caused it to go completely down. I do now remember what the MSF taught me.

 

[Motogiro]

Also insure that your rear braking system is working correctly.

 

[PcH]

Also insure that your rear braking system is working correctly.

How can I do that?

 

[Erci]

The bike was slowly turning sideways. I felt like keeping on the brakes in the moment would've caused it to go completely down. I do now remember what the MSF taught me.

It's a good thing you rode away from that situation without crashing. The idea is that even if the bike is stepping out to the point where you think it'll go down, you are much better off low-siding (just falling on the side and sliding) versus high-siding (getting violently ejected up off the bike).. which is exactly what can happen if the rear steps out enough while locked up and then rear brake is released .. rear tire regains traction and snaps very quickly back into straight line.

 

[Erci]

How can I do that?

Start by inspecting brake pads. Make sure there's enough braking material left on them and there's no contamination (funny looking color on braking material or wet look).
Spin the rear wheel when the bike is on center stand and apply rear brake slowly.. can you modulate it (just drag it slightly) or is it on/off?
When the brake is fully engaged, is there a mushy feeling at the lever?

I am betting there's nothing wrong with your rear brake though.. you just applied enough of it to overcome the available rear tire traction at that moment.

 

[FIZZER6]

My coworker who raced bikes for a number of years and has been street riding some 30 years and had 4 crashes in that time told me to never hit the rear brake in a panic situation...EVER. The reason being that in a panic braking situation you will always over-brake and locking up the rear has the highest potential for a high side crash which (if the panic was caused by a cager...you do not want to high side in front of them!) If the front locks worst case is you low slide and perhaps are able to control your slide and the bike strikes the obstacle first instead of throwing you spinning out of control into it. The only time I use rear brake is around town and when making a turn through an intersection to keep the chain from jerking when I apply throttle through the turn.

 

[Erci]

My coworker who raced bikes for a number of years and has been street riding some 30 years and had 4 crashes in that time told me to never hit the rear brake in a panic situation...EVER. The reason being that in a panic braking situation you will always over-brake and locking up the rear has the highest potential for a high side crash which (if the panic was caused by a cager...you do not want to high side in front of them!) If the front locks worst case is you low slide and perhaps are able to control your slide and the bike strikes the obstacle first instead of throwing you spinning out of control into it. The only time I use rear brake is around town and when making a turn through an intersection to keep the chain from jerking when I apply throttle through the turn.

One thing that changes this approach for me is riding with a passenger. Much more weight and traction on rear wheel.. far less likely to lock up the rear. I've never seen the number break-down for maximum braking with a passenger, but I bet the rear can easily do 20% in this situation.. if not more.

 

[FinalImpact]

I've got a couple things to add.

Setting up your front brake lever:
I did this last weekend before a 200 mile ride. I'm 5'10" with a 30" inseam. most of my height comes from the torso up. The factory bar has dimple where the brake lever halves align. The factory setting has my wrists bent up at an angle because my shoulders higher from the seat than the average rider. The levers must be corrected for my height!!!

With your bike on the center stand, relax as if riding; If you find your wrist is not parallel to your forearm, rotate the lever until it is! WHY? Your hand will have a greater mechanical advantage pulling the lever down if your wrist is straight in relation to the forearm!

Arch your wrist back towards your forearm as far as it goes and make fist. Notice you have little strength. Repeat with your wrist being flat and in-line with your forearm! Notice your strength almost doubles?!!

Sit on your bike and rotate the brake and clutch levers so your wrists are flat and parallel to your forearm. BE WARNED, if you make a large adjustment (because you are taller) YOU WILL GRAB THE BRAKE HARDER!!! BE CAREFUL!!!

Doing this simple thing will also reduce fatigue and help correct bad riding posture. :thumbup:

Brake pads:
When brake pads are replaced always do them as sets front and back. The reasons are many:
1) likely they will match compound (prevents one end from locking)
2) they begin the bedding in process equally; meaning one end isn't more sensitive than the other.
3) you adjust to them equally
4) the whole system is inspected

 

[VEGASRIDER]

In general, reading all the posts, most have given correct and good advise.

However, to only get in the habit of using the front brake is a very bad advise in my opinion. For you to stop the bike in the shortest distance that you safely can, is to apply both brakes. Yes, the front brake can account up to 90% of your stopping power, but why not use the available percentage leftover from your rear? This could be the difference of hitting something or not. Believe it or not, in an Emergency situation, inches count! This is motorcycling 101, pretty basic stuff here.

Since all of the weight is transferred to the front by your suspesnsion compressing forward, creating friction and traction against that front tire, it's only when the weight begins to transfer back to the rear when your rear tire really starts to kick in.

Maximum braking is to apply both brakes without locking either wheel! This takes lots of practice and you must develope muscle memory in order to do so. Most Riders and Drivers natural reaction is to slam on the brakes whenever they need to brake hard. We have all done it in a car, but if you were to slam on the brakes on a bike, it will most likely crash. This is why everyone needs to practice their quick stops on a regular basis. I do, every week! Progressive squeeze is the key, similar to slowly squeezing your girlfriend's boobs, if you grab them, you'll probably will get slapped! Same as crashing in my opinion.