Joined: Jan 2010
Posts: 9,830
Likes: 1,807
From: Northern California
Bikes: Cheltenham-Pedersen racer, Boulder F/S Paris-Roubaix, Varsity racer, '52 Christophe, '62 Continental, '92 Merckx, '75 Limongi, '76 Presto, '72 Gitane SC, '71 Schwinn SS, etc.
Which pivot spring that you decide to tighten should depend on what freewheel you want the derailer to conform to.
I always go tighter, not weaker, but switch to ball bearing pullies first so as not to create unwanted extra friction.
Drilling the B-pivot stop plate may require a good and sharp drill bit, I'd start with 5/64 or 3/32, which might be big enough for the end of the spring.
I might use an Arabesque long cage derailer with a triple, but not with a big freewheel (I don't like the sluggish shifting between the smaller cogs that results from the huge chain gap).
Last edited by dddd; 06-25-13 at 12:54 PM.