[CR]fixing dropouts.

(Example: Production Builders)

Date: Wed, 20 Aug 2003 21:45:24 -0400
From: "HM & SS Sachs" <sachs@erols.com>
To: neill1234@yahoo.com, Classicrendezvous@bikelist.org
Subject: [CR]fixing dropouts.

Neill Currie wrote:

<snip> ------------------ Question #2. I have an old bike which has been ridden for decades, which has long horizontal steel dropouts on the rear. Over the decades, and probably as the result of too zealous tightening of the rear wheel, there has been some deformation of the faces where the rear axle sits in the frame, making it somewhat difficult to achieve correct chain tension(it is set up as a fixie), as the wheel want to move when tightened to the thinnest part of the dropout. To rectify this situation, am I correct in assuming that I will need to get a couple of beads of steel welded to the area, and then grind/file away all the excess to make the dropouts flat again? Brazing material would be too soft in this area for this purpose, right??

Many thanks in advaance for any help.

=====

Neill doesn't give us a couple of parameters that I'd regard as critical. In particular, is he trying to save paint or chrome in the area of the dropouts, and is the frame such a classic that the dropouts themselves should be preserved... Let's assume that the old frame and its finish should be preserved. In that case, if the axle is long enough, I'd epoxy a sheet metal plate cut to match the meat of the dropout in place. Epoxy can be undone, if necessary, with much less heat than de-brazing. This might work better if you grind the present surface to fairly flat, to minimize the likelihood of the epoxy deforming.

If you have a devil-may-care attitude about this bike, it's not a big deal to cut out the present dropouts and install new ones, but it wreaks havoc on the finish (if chrome stay ends, liberally coat them with flux to keep oxygen from getting to the chrome while you heat it, and keep the heat low). The secret to removing the old ones is to cut through between the seat stay and the chain stay, so you only have to heat one joint. I do this one side at a time, so I can keep the same spacing and alignment by using a wheel or jig to reference the new one's position against the old (first side) or against the newly installed one (second side). Experienced frame builders may be much smarter.

I've also taken a different tack with a bunch of Schwinn Town & Country curved-seat-tube tandems, set up originally to run 26" wheels. To get clearance to run 700c, I made (and later had made) "half-dropouts." Because of the tight clearances, I wanted to run with verticals. These brazed--on adapters required cutting off the rear drop-out along the top of the horizontal slot. Then the new units, which had a lip on the outside for stength and to seat the QR or nut, were brazed in place, usually with a washer on the inside. Lot of trouble, but fun bikes.

harvey sachs
mcLean va