This sounded like BS to me

[GL4435]

A friend of mine sent this to me today ... said he just read it, and it was a good explanation ... it sounds ridiculous to me. Was curious what others thought about it.

I locked up the rear brake at about 20-30 miles an hour and went into a classic motorcycling situation:

When you lock up the rear tire on a bike the tire distorts/contorts, and when you let up on the brake, the tire snaps back into shape, and this dispersed energy goes through the bike frame like an electric current, with no ill effect until it gets to the handlebars.

Unless the rider compensates for that energy transfer with a cool head and plenty of experience the handlebars go into the classic "head shake" (an uncontrollable wobble of the bars) which will cause the whole bike to start acting like a bucking horse and throw the rider (head first) (actually, chest first, then head) to the pavement, ending in an accident known as a "High Side".

 

[mferriter]

I've locked up the rear on previous bikes with no issue, except for the black skid mark and smell of burning rubber. If you get turned sideways, however, bad things can happen.

Locking up the front is WAY worse.

 

[Geezer]

Locking up the back brake and then letting go can result in a challenging experience, but I don't think it has anything to do with tire distortion.

 

[RossKean]

I would say BS. If you lock up the rear and the tire slips out a bit and you keep the front wheel straight to the line of travel, shit can happen when you release the brake. All of a sudden, you have a rear tire with traction aiming in a different direction than the direction of travel. If its out very much, its an instant high-side. I don't buy the theory of shock from a deformed tire making its way up to the handlebars.

Ross

 

[SwollenRaccoon]

When you lock up the rear, it wants to come to the front, sliding sideways. You can ride that out fine, with opposite steering input. The trouble will start when you reach full lock, and can no longer compensate.

Same thing will happen if you slide the rear with the throttle. If you're smooth, and not overly aggressive, you can handle a little angle difference. The problem is when you close the throttle rapidly, which is the initial survival reaction. What you have then is your front tire pointing one direction (down the road), and the rear tire, which was locked or spinning, essentially making it a skid, now wanting to resume rotating about its' axis (the axle), pointing toward the ditch. It wants to snap back in line with the front tire, and will pitch your derriere up off the saddle. If you're lucky, you caught it before disaster strikes, and land back in the saddle, with a big pucker mark in your underpants. If you're unlucky, you get the classic high side, and bounce down the road. Owee.

A lot of people will say "I had to lay 'er down". The translation is usually, "I panicked, locked up the rear, and hit the ground before I could let off the rear brake". Of course, there are a billion other factors possible, so take this for what it's worth, which is absolutely nothing.

Practice hard stops. It could help.

 

[Intech]

If the tire distorted to the degree that it causes what is stated then you either have a really bad tire or are seriously underinflated.

 

[Redfish Hunter]

All air filled tires get "distorted" to some degree while in normal use. The same principles that make it possible to dribble a basketball are in play with your tires. This is nothing new, it's nothing to worry about. When you hit a bump, it "squishes" the tire. Practically any control movement and certainly every irregularity in the road surface distorts the tires. They are designed to do this, the suspension is designed to control it and the chassis as a whole absorbs it. If you want to see a true "highside" pull up some old video of GP racing when they were running 500cc two strokes. It sounds to me as though someone is looking for a motorcycle component to take the blame for poor riding skills.

 

[ronhawker]

BS! Apparently never rode or raced dirt bikes or MX. Locking front or rear wheel can be ridden and used to corner. Watch Superbike or MotoGP and watch both ends sliding on occasion. There are some good drifting videos on YouTube of motorcycles.

Agree on the "had to lay her down" nonsense about panic stops and drops.

 

[wfooshee]

BS! The danger of locking the rear is getting the bike sideways. If the front is braking hard and the rear is locked, the front is actually trying to slow down more than the rear. If the road is crowned, the rear will go downhill, toward the curb. Letting go of the rear brake restores rear grip instantly, kicking the tail back behind the bike; high-side.

There's no force transfer to the handlebars, but there is a significant event at the rear axle!

A sliding tire has MUCH less grip than a rolling tire. That's all there is to it.

 

[CAJW]

The only "Head Shake" in this equation is mine when I read the BS your friend fed you. I've had the rear step out plenty of times (thankfully mostly on dirt and by design) and never have I had the head shake.

 

[wheatonFJR]

...A sliding tire has MUCH less grip than a rolling tire. That's all there is to it.

That's true. The front tire rarely has much grip when sliding...but then the sliders start gripping the road and the plastic and cans as well...so you stop eventually.

 

[mferriter]

...A sliding tire has MUCH less grip than a rolling tire. That's all there is to it.

That's true. The front tire rarely has much grip when sliding...but then the sliders start gripping the road and the plastic and cans as well...so you stop eventually.

Exposed flesh also grips the road pretty well, which is why it tends to stay attached to the road when you'e sliding down it without your gear.

 

[SkooterG]

Oh yes, that was good for my daily funny. OP's friend really has an active imagination.

 

[Afast03nNJ]

Tire distortion causing the loss of control?

Let's apply that theory to the power of the FJR and you'd lose control every time you twist your wrist.

That's just plain old bull shit

 

[FJRBluesman]

Do I really need to state the obvious...?

Tire distortion has always been an issue.

When the molecules are in motion and the force is forward it only goes to say that laws of physics kick in, specifically the law by world renowned physics professor B.S. Axlerod, molecular dragtivity in rotational motion mass of deceleration.

Look at the tire of a top fuel dragster under deceleration.

Note how the molecules in motion and under declaration are collecting forward leaving a void in the rear area, here handling would be compromised.

I rest my case! Case closed!

 

[RadioHowie]

Don't EVER believe anyone who has to post the same thing twice to get his/her point across!



Don't EVER believe anyone who has to post the same thing twice to get his/her point across!

 

[beemerdons]

Don't EVER believe anyone who has to post the same thing twice to get his/her point across!



Don't EVER believe anyone who has to post the same thing twice to get his/her point across!

RH: Bluesy is a Dork!



RH: Bluesy is a Dork!

 

[wfooshee]

Post count reset to 0 in 3 ..... 2 ...... :lol:

 

[beemerdons]

Post count reset to 0 in 3 ..... 2 ...... :lol:

Yo Walt, I think that eight times is the charm!