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Poll: Which brake, front or back or both?(10 posts)

Poll: Which brake, front or back or both?Woof the dog
Feb 25, 2003 9:31 PM
I use lots of front one. Rear is so easy to lock up.

How about you?

Woof the dog.
Engineer's answerAlexx
Feb 26, 2003 4:11 AM
Always use the front brake. It provides something like 65% of braking force under normal conditions and also, the harder you brake, the more the load shifts forward. This reduces the load on the rear wheel. The less the load, the less friction on the rear wheel, and the easier it is to lock up. At maximum braking, the load on the rear wheel is zero.
At higher speeds use the rear to feather me downthe bull
Feb 26, 2003 4:41 AM
or start with rear hard then go to front as I fadeout on the rear.dont want to lock any thing up.Mental ABS !
You can also shift you body weight back this helps too.
Both, most on the front and drag the rear a little....asphalt assault
Feb 26, 2003 4:57 AM
...Like the poster above says, most of your braking power is done by the front because your weight is shifting foreward under heavy braking...while your rear wheel "unloads". It's a good practice to drag the rear a little because it helps to stabalize the bike.

Try shifting your butt back on the seat a little under heavy braking and it will help your rear tire hook up better and the effect of grabbing a handful of rear will be more pronounced.

Braking more efficiently means that you can brake later while heading into a turn and that will enable you to come out of the turn harder and faster.
I do something a little un-orthodox...joekm
Feb 26, 2003 6:28 AM
I've done it this way for years and I'm the only person I know who does it. In a hard turn, I actually will alternately pulse the brakes to modulate my speed while maintaining control authority in the turn.

Generally speaking, the front brake will give you more control authority for reasons already mentioned. However, using it exclusively or over-using it *can* destabilize the bike in a critical situation. I.E. you should be using both brakes and modulate as required to get necessary authority without giving up stability. It's a feel thing, if what you are doing works then you are probably doing it right.

BTW - this is common theme when you talk about control of anything. Generally speaking, control authority comes at the expense of stability and vice-versa, sort of the yin and yan of control theory.
Learn to Turn53T
Feb 26, 2003 7:13 AM
No brakes in a properly executed turn, at any speed. The key to good turning is to use the traction of the tire against the road to change the direction of your travel. If you are braking you are using that same traction to slow yourself down. You very quickly run out of traction and problems follow.

BTW, One of my hobbies is control systems engineering, and I never see teh tradidtional texts and papers talk about "control authority". Can you point me to a paper that introduces/defines the concept?
Control authority...joekm
Feb 26, 2003 10:24 AM
pardon my laymen's terminology (I assume the average reader is not a mathematician ;) ). In the literature (Franklin & Powell, et. al.) you may see this termed as "gain".

Generally speaking, an increase in gain tends to cause a decrease in stability. A more detailed illustration could be found by looking at root locus plots for various systems. For some systems, adding gain can stabilize to a point, but there is always a threshold where more gain causes problems.
Thanks, gain I know about! (nm)53T
Feb 26, 2003 10:29 AM
In a hard turn I would avoid use of brakes if possible...rwbadley
Feb 26, 2003 7:05 AM
try to set up your turn beforehand. Slow before the turn, this will allow the rubber to do nothing but grip for the corner. Generally, the use of brakes in a corner will cause more chance of a wheel slipping out.

I use front the most, and rear as an accesory. Always in combination, but I will focus modulation on the front.

RW
Bothtarwheel
Feb 26, 2003 9:44 AM
The front brake provides most of your stopping power. However, it is much easier to lose control and wreck if you brake with the front alone. I learned this the hard way when I used to ride dirt bikes (motocross) in high school. If you brake only with the front on some lose sand, gravel, dirt, etc, it is very easy to go down. I learned riding motorcycles to always use both brakes but apply more pressure on the front for faster stopping.