Puzzling questions

[rocker59]

Holy smokes. You mean my wife and I have been riding wrong all these years. Good lord. Thanks for saving us.

Pardon the sarcasm, but the B.S. is getting mighty deep in this thread.

 

What have I said that is BS ?

[Slavomir Musilek (R.I.P.)]

LA, CA and Brno, CZ, depending on the part of the year:)

 

 

tak to je paráda potkat tu někoho z čech

[Guzzi2Go]

Both times when braking, pulls hard left. Screams brake problem to me. Especially the left front. Pull the calipers off, check for debris, check rotors are not bent/warped/damaged, check condition of brake pads, pull in brake lever and check if all pucks move (don't pull hard enough to move the pucks very much - risk shooting them out completely), you should be able to press them back in with your hands slowly, check the alignment of the calipers and rotors, and the caliper mounts. If free floating rotors on the 1100i, check that the rotors have some in and out flex at the float points.

 

good luck!

Just wondering....

 

How do bikes with a single brake rotor work? Is a crash pre-programmed?

[Dan M]

Just wondering....

 

How do bikes with a single brake rotor work? Is a crash pre-programmed?

 

This could turn into a favorite thread. Seems there is a lot speculation on how things work.

 

I have one question. If a bike is equipped with one front disc brake and it is on the left side of the wheel, will it cause the bike to pull left when braking because the rotor is on that side or right because the caliper is pushing forward on the left side of the fork?

 

Chew on that one for awhile.

[Guest ratchethack]

This could turn into a favorite thread. Seems there is a lot speculation on how things work.

 

I have one question. If a bike is equipped with one front disc brake and it is on the left side of the wheel, will it cause the bike to pull left when braking because the rotor is on that side or right because the caliper is pushing forward on the left side of the fork?

 

Chew on that one for awhile.

YYEEEEEEEEEEEEEFFFFFFTTTTT!!!!!!

 

Not to worry, Dan.

 

I'm confident we'll be graced with an enlightened answer via previously quoted screaming brake problem voices PDQ.

[gstallons]

This could turn into a favorite thread. Seems there is a lot speculation on how things work.

 

I have one question. If a bike is equipped with one front disc brake and it is on the left side of the wheel, will it cause the bike to pull left when braking because the rotor is on that side or right because the caliper is pushing forward on the left side of the fork?

 

Chew on that one for awhile.

When you apply the rear brake (with the caliper/rotor on one side) do you notice ANY pull ?

It makes on difference as far as one rotor being on either side.

I have thought about this and if the caliper is behind or in front of the forks with no real answers....

[Guest ratchethack]

Makes no difference wotsoever, Gene. All traditionally mounted calipers -- single disk, dual disk, up, down, front or rear mounted calipers, have ZERO effect on steering, regardless of front fork or rear swingarm. Same with a dual disk front where only one caliper is operational.

 

Anti-dive forks work by mounting the rear-mounted caliper on a floating caliper carrier with a linkage arm anchored to the upper, suspended part of the fork. Braking forces in this case are transferred to the chassis, cancelling out brake dive. If you were to mount a floating anti-dive front caliper in front rather than in the rear, it would compound brake dive.

[gstallons]

Preston Petty sold this anti-dive setup for MX bikes in the late 70s. It was a linkage that hooked up to the top of the fork upper or steering head (I can't remember) and to the brake drum backing plate. When you applied the front brake the drum rotated and pushed up on the linkage extending the fork length and not allowing the weight of the bike to push down on the forks.

The Earls design front forks* had this same characterisics as far as picking up on the front instead of pushing down when front brakes were applied.

 

* I assume you are old enough to know what these are!

[Guest ratchethack]

* I assume you are old enough to know what these are!

I'm afraid so. I was a lad when Earles forks were common in motocross and ISDT.

 

The legendary CZ 125

 

Sachs-DKW

 

and last, but by no means least,

the incomparable Guzzi V8

Not Earles forks, just leading link

[GuzziMoto]

What have I said that is BS ?

 

Sorry.Not trying to single you out specifically..

Just speculation about the riding ability of the OP and all this B.S. about the dangers of the front brake and that if you use the front brake and not the rear atlow speeds you will surely crash.I thought those kinds of old wives tales were only for Harley riders.

As far as Eales forks, I'm not that old but as I recall as long as the lower link is lower at the axle then at the rear pivot then it has anti-dive, whether intended or not. Closest I have come is racing a Tesi.

Don't think a brake disk on one side or the other will make a bike pull left or right. But if your brakes malfunction it could cause the brakes to lock up suddenly like the OP experienced. But it also could just be an old tire.

[Guest ratchethack]

As far as Eales forks, I'm not that old but as I recall as long as the lower link is lower at the axle then at the rear pivot then it has anti-dive, whether intended or not.

Sorry, my bad. Correction made. Thanks for setting me straight. A remembery is a terrible thing to lose. Leading link forks do have inherent anti-dive characteristics. The anti-dive effect is simply most effective when axle and link pivot are at the point of fork travel when they're perpendicular to the steering stem, and it drops off on either side of this point.

[Dan M]

I can smell wires burning from overloaded circuits now.

 

In order to have a brake pull you have to have two (front) wheels! So untill MG makes a three or four wheeler. A brake problem will not make it pull. It may make the wheel lock, which can result in a slide to one side or the other but it will not make it pull.

 

If this thread go much further we'll have people not using their front brakes at all. Then what is left? Oh yea, the beloved V11 rear binder. Now there's a trouble free bit of engineering. At least some weight savings can be had with the removal of the horn because the resulting rear wheel noise will render it usless anyway.

 

Ratch, I love your "dive assist" set up. Perhaps some drag racers can make use of it.

 

quote:(gstallons)

When you apply the rear brake (with the caliper/rotor on one side) do you notice ANY pull ?

 

Only when I'm backing up.

[GuzziMoto]

I can smell wires burning from overloaded circuits now.

 

In order to have a brake pull you have to have two (front) wheels! So untill MG makes a three or four wheeler. A brake problem will not make it pull. It may make the wheel lock, which can result in a slide to one side or the other but it will not make it pull.

 

The OP was about the front brake locking up, followed by the forks going full lock. Others may have speculated on the cause of the forks going full lock but, I'm sorry to say, I'm confident in saying the forks went full lock due to the front tire locking up. It is a normal part of crashing when the front tire locks. It doesn't have to happen but it often does. I don't think the forks going full lock is the root of his problem but merely an after-effect of the forks locking. The question in my opinion, is why are the forks locking. The part about one caliper sticking or binding has more to do with causing a problem with the brakes and nothing to do with the forks going full lock after the front tire locks up.

[Guest ratchethack]

The OP was about the front brake locking up, followed by the forks going full lock. Others may have speculated on the cause of the forks going full lock but, I'm sorry to say, I'm confident in saying the forks went full lock due to the front tire locking up. It is a normal part of crashing when the front tire locks. It doesn't have to happen but it often does. I don't think the forks going full lock is the root of his problem but merely an after-effect of the forks locking. The question in my opinion, is why are the forks locking. The part about one caliper sticking or binding has more to do with causing a problem with the brakes and nothing to do with the forks going full lock after the front tire locks up.

?? ??

 

What gives you the idea the fork "went full lock"??

 

You mentioned it no less than 7 times, but I don't find any mention of the fork locking anywhere -- in any of his posts.

 

In fact, in his OP, Pavel posted:

. . .no apparent fork problem. . .

[rocker59]

I think he's referring to the forks going to the steering stops during a tank-slapper, ie "full lock"...

 

From the OP:

 

"suddenly the front wheel locked and I got a immediate left-hand tank slapper and ended on the ground. It was on a bit of a wet surface so I blamed it on this, although it felt weird. Just the front wheel broke the traction a bit fast. Anyway, repaired the broken shifter and continued riding. Not much other damage, no apparent fork problem, no weird handling afterwards.

 

Accident no 2: Riding at some 30mph, when I saw someone at distance crossing my path, start braking, again no emergency, dry conditions, perfect surface. I got a very quick, again left-hand tank slapper and low-sided, this time with a bit more damage to the bike and myself. THis was very surprising since it should absolutely not happen"