Extreme Makeover: Lug Edition

For an upcoming mixte (step-through) frame project, I needed a lug set which includes the two special lugs to carry the steeply sloped top tube. Despite the variety of modern cast lugs available for traditional frames, there are no non-proprietary lug sets currently being produced for the mixte format. Searching the offerings of old-stock components, I found a set of vintage pressed lugs which, under all that tarnish, showed some potential.

But I never really cared for this Nervex style, and the sockets for the top tube and down tube are cut too blunt to carve any sort of nice point. This called for a major overhaul....

The first step was to square off the end of the down tube socket, and braze on an extension which can later be shaped into a point. In the photo below, the junction has been filed to reveal the fine brass-colored line of the joint.

This lug-shaped-object then was carved to create a new long point, and to remove most of the original Nervex features.

This new overall profile is consistent with the simple lug styling that I had envisioned for this frame. But I wasn't done yet... the shorelines needed refinement, and this lug needed to be thinned.

The photo below shows the brazed lug, sporting a completely new style for this old lug set. Who would ever guess how this lug started out?

Brakes: Act 2

When you find a truly great component, you want to keep using it forever. Sometimes, however, that requires a little creativity.

When Randy and I started discussing what he wanted in a new frameset, he was definite about wanting to modify a rare set of DiaCompe 700 centerpull brakes to mount via braze-on bosses. The photo below shows this brake model as it was originally produced, with the beautifully designed caliper arms mounted using a universal-fit yoke and center bolt.

In contrast to Mafac centerpulls which are readily convertable to braze-on bosses, the center-mount DiaCompe 700 uses a spring shape which doesn't allow the original spring to anchor to the boss as it should. In addition, the dimensions of the DiaCompe's pivot are sufficiently different from current brake standards that this brake doesn't mate with stock bosses. The solution was to fabricate a set of hand-wound stainless steel springs. After several prototypes, I arrived at the spring profile shown in the photo below.

This photo also shows the custom braze-on bosses that I made for this project. The dimensions on these bosses are optimized to mate with the DiaCompe 700 brakes' original pivot bushings. And, since bosses and springs were designed in concert, the single spring anchor hole is all that's needed.

The photo below shows the DiaCompe 700 brake arms mounted to the braze-on bosses. Those are 50mm fenders mounted with 13mm of clearance over 35mm Pasela tires. These brakes are both beautiful and well designed, and I'm happy to give them a second life on this new All-Road frameset that I know Randy is going to ride hard.

Update ... After updating these brakes with modern Kool Stop pads, pulley-style hangers and shorter straddle cables, Randy reports "I've never ridden with brakes that stop so well and modulate so nicely. All that work was well worth it."

Small Details

This fork started out as a low-trail Frame-Neutral Replacement Fork™ for a Rivendell Rambouillet. As we discussed the customer’s current setup and future plans, the fork’s specification expanded to include some neat custom features.

The customer requested separate under-crown mounting points for both a fender and the new Velo Orange randonneur front rack. This rack, intended to be used with caliper brakes, features a center tang made from a flat strip which attaches underneath the crown. With the limited space available in the open end of the steerer tube, this called for a carefully designed piece to provide two threaded sockets with enough separation to be functional, enough depth-of-thread for a solid connection, and no interference with the brake’s center bolt.


The mounting solution shown above provides a 6mm socket (front) for the rack, and a 5mm socket (rear) for attaching the fender. The spacing between the sockets is maximized, and the socket depth provides 5mm of full contact thread. The bridge that carries the sockets is about 2mm thick, and, with this crown, provides the extra bit of vertical drop required to allow the rack’s tang to pass cleanly beneath the arch of a Tektro R556 caliper brake. With the additional fork length built in to compensate for the added fork offset, all of this stuff underneath the crown won’t interfere with the clearance needed to properly position the fender over a 700Cx30 Grand Bois tire.

The customer will use a generator hub, running the light wire all of the way up the right fork arm, then down the left arm to a low-mounted light. To eliminate that whole unsightly zip-tie and p-clamp scene, this fork received a full set of brazed-on lighting wire guides, along with a dedicated light mount low on the left arm.

Small details like these really clean up the appearance of a bicycle. In doing so, the details themselves tend to disappear from the casual observer. But they’ll always be there, providing a perfect foundation upon which to carry your load, keep you dry and light your way.