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Old 12-12-2012, 11:07 PM   #101
PhilB
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Quote:
Originally Posted by crofrog View Post
Not really, doing the same wrong thing for 300k miles is no different than doing the same wrong thing for 5 miles (not saying what your doing is wrong per se).
But repeatedly doing something risky successfully for 25 years in the real world, where doing it wrong could and likely will fuck you up sooner or later, means doing it mostly right. I try to not have to emergancy brake, but I can't predict absolutely everything all the time, especially in heavy traffic like SoCal perpetually has. So it happens now and then. I consider the emergency stop to be a *very* important skill, as any time you need to do it, the consequences of doing it wrong are likely to be heavy. So I have taken care to know what I'm doing there. And the method I outlined is the best one there is.

Quote:
Originally Posted by crofrog View Post
How do clutch plates wear when they are fully engaged?
In a literal sense, the clutch comment is from the fact that engine braking usually involves downshifting, which involves the clutch and more specifically involves modulating the clutch with some slip as you re-engage it after the downshift so as not to break the rear wheel loose. Which does cost some clutch wear. More generally, engine braking involves reversing the stresses on the entire drivetrain, and pushing backwards on everything, which really isn't a great idea. So for best care of the bike, it's better to not do a lot of engine braking, and if you want to apply some braking force at the rear, use the rear brake, as that's what it is designed for, and not the engine, which is not optimized for that purpose.

Quote:
Originally Posted by crofrog View Post
I'd love to see some side by side test done with riders using both brakes versus just the front with repeated stops I think you'll find that adding the rear removes very little stopping distance while the chance of getting it wrong while stopping with the rear brake is allot more. You fuck up and lock both brakes you're going to have a much worse time than just locking the front.
That has been done MANY times, by various magazines and other groups. EVERY time, they find that using the both brakes makes you stop faster. On some bikes (cruisers, tourers, scooters) the rear brake adds a lot of braking power. On standards a middling amount. On sportbikes a small amount, but not zero. And on all but the best surfaces, the rear is more helpful. I think the last one I saw was from Cycle World, and a couple of the very best riders were able to equal their distances using the front only vs. both, but still only a couple of them, and only on sportbikes on good surfaces.

And no, if you lock the front and are less than a supreme expert, you are falling down regardless of what the rear is doing. So you won't have a worse time at all if both lock vs. just the front. Nope. Wrong. Fail.

Quote:
Originally Posted by crofrog View Post
My thoughts on why rear brake usage during panic stops is bad.

1. You're added _twice_ the amount of task for stopping you now need to manage 2 separate brakes systems and tire level tractions.
2. The majority of the bike's stability is coming from the gyro of the running engine and the spinning wheels. If you lock the front and the engine is still spinning and the rear tire is still turning you have a very good chance of reducing pressure and riding out of it because the bike is still stable and tracking straight.

You lock the rear which is very easy to do while hard on the front and kill the engine you've lost much of your stability and your ability to re-accelerate and if you then lock the front on top of that the bike is completely unstable. To avoid killing the engine you now need to manage a 3rd control.

The nature of an emergency is that you aren't planning for it. It's hard to properly modulate 7 controls (front brake, rear brake, clutch, steering, body position, throttle) during a full on stop when doing planned full on stop, like on a race track.

It's going to be damn near impossible to pull it off when you didn't except it, because face it. If you where in a position to do it all right you'd not be in an emergency stop because you'd have seen it coming and already taken action to avoid the situation.
Have you actually ridden a motorcycle before? Do you know what the clutch is? Even the newest rider knows to pull in the clutch while braking, and that's a universal reflex, requiring no extra attention, among people who have actually ridden more than once. Sheesh.


PhilB
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1993 Ducati M900 Monster "Patina" (230,000 miles, so far) -- 1995 Ducati M900 (wife's bike) -- 1972 Honda CB450 (daughter's bike) -- 1979 Vespa P200 (daughter's scoot) -- 1967 Alfa Romeo GT Jr. (1300cc) -- 1964 Vespa GS160 (160cc 2-stroke) -- 1962 Maicoletta scooter (275cc 2-stroke) -- 1960 Heinkel Tourist 103A1 scooter "Elroy" (175cc 4-stroke)

PhilB screwed with this post 12-12-2012 at 11:16 PM
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