Bicycle Mechanics - P/B screw question

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B1105

07-05-03, 04:46 PM

Hey, I forget which is the P screw and which is the b screw. However I know one of them controls the cage of my r.derrialeur and the other controls the spring or something behind the parrallelagram. I have heard that some downhillers increase one of the screws in order to make the spring rate of the cage faster. The result would be a quicker shift. Is this true? And can I do it on my road bike? It has campy centaurn 10 speed components.

moabrider47

07-05-03, 08:05 PM

The "B" screw changes the distance of the upper pulley from the cassette. When the screw is improperly adjusted, the chain can bounce up against the cassette teeth. Having a properly adjusted "B" screw will make for better shifting. I can only describe the "B" screw as being the one that kind of sticks up in the back of the derailleur. I don't know what you're talking about in terms of downhillers playing with this screw. You sure they don't just play with the cable tension?

-Moab