P-tension spring - two settings?

Well, used the other setting, and all works well. Though I'd still expect to need some b-tension for a large cassette

Not everyone has enough disposable income to not think twice about spending £30.

Argh blank post bug - here's the text:

Can't find any info on this at all online - wonder if anyone here knows?

I'm fitting a used but good condition 5700 rear mech to a friend's bike, and even at minimum B-tension, the g-pulley isn't getting anywhere near close enough to the cassette to provide good shifting. Given that this is an 11-28t cassette, that seems very odd.

So I found that there are two settings for the P-tension springs (the one that rotates the pulley cage) and wondered whether changing this to the other setting may fix the problem? It seems that the P tension spring and the B-tension spring balance each other, so increasing the P tension should have the same effect as reducing the B-tension (which is already at minimum).

Anyone got any experience of this?

I wondered if the chain was too short (this would rotate the cage away from the cassette but I've checked the small/small and big/big combos and it looks like it couldn't go any shorter or longer.

Anyone know which hole of the two the P-tension spring should be in? I haven't managed to find anything in the Shimano manuals about it.

Might just have to give it a try and see what happens.