Friday, November 27, 2009

Merry Christmas Clive: Front Brake Hangers and Stops

My lucky bike Clive has already received his first Christmas gift.

Since my stem came hanger-free, I have been thinking over what the ideal location is for a front brake cable stop. Originally my idea was that the stop should be put smack dab in the middle of the stem extension. This is a crude implementation of the idea. I was thinking one could put a water bottle boss on the top of the extension, tap it out to M6, and then put an adjuster in the top. Two complications with this plan: you'd have to angle the boss such that it follows the angle of the headtube, which is the angle the brake cable needs to be at. And you need to drill an exit hole in the bottom of the extensions in the right place to follow that same angle. And then other questions: would it weaken the stem having a braze-on there? Stems are under a lot of stress, and you don't want them to fail. And would it be annoying that raising and lowering the stem would tighten and loosen the front brake? Also: this idea is pretty awful if you're using aero brake levers (I'm using these).

The other option for a stem-located front brake cable hanger is the one on this Singer stem. Very attractive, and simpler than the above-mentioned idea, since it doesn't pass through the extension. Also, it doesn't cut through the extension, so no chance of weakening it. The drawback of stem-adjusting affecting front brake position remains. And any stop located below the stem is going to cause the housing to rub against the stem, producing rattling and wear of the chroming.

Finally I decided that a headset-mounted stop—the most obvious idea—was probably the best one. Regular steel Mafac hangers are nice looking but don't have cable adjusters. Weinnmann hangers have adjusters but are funny looking. The nicest headset hangers are again those on Alex Singers. Since these need to be made by hand anyway, it would be easy enough to made the stop a threaded boss capable of handling an adjuster.

I sent the above link to my friend Olivier and he got an idea to made a headset-mounted hanger using wires rather than a tube. Before I knew what was going on, he had designed and built the hanger!—the one photographed above. And it's glorious! It's very attractive, it incorporates an adjuster, and it even has an extra "loop" to guide the housing into the stop and possibly reduce rattling and finish-wear. Ingenious! The only possible downside is flexiness—maybe prolonged braking force will serve to "flatten out" the bend of the wires. We'll see! Update: Some actual testing has revealed that it's way too flexy! Back to the drawing board!

Some of you may remember that I was originally going to locate the adjusters right in the brake levers, Mafac-style. I had my Mavic levers tapped for some very attractive Dia Compe adjusters. But since the brake lever body on these Mavic levers is split, the threading was a bit "loose." I'm happier having the adjuster anchored somewhere more stable—and those nice adjusters will look nice on Olivier's hanger!

Saturday, November 21, 2009

Clive Arrives

I am very pleased to announce that Clive—my randonneur frame by Dan Polito—has finally arrived on Canadian soil. His arrival was pushed back by many months due to a series of delays. But he is now with Noah at Velocolour. Since I myself am still living in Hungary, my friend Olivier has kindly sent me a whole bunch of photos of the frame and stem. (The custom rod-operated FD accidentally got left behind. It will arrive soon.)

Based on what I've heard from Olivier and seen in these pictures, Clive seems like he's in good shape. As some of you may remember, I sent Dan an extremely detailed order sheet. I'm a very picky customer, so Dan had a tall order. All the basics are right: the brazing is good, the finish is nice, and the clearances are all within a 1/4" and seem right. He also added a number of nice, original touches: nice dropout treatments, an interesting seatlug/sleeve. As a pleasant surprise, he built my fork from Jack Taylor Special Reynolds 531 imperial-oval blades and an old sand-cast crown.

Photos and commentaries follow.

Headtube, fillet-brazed joints, and single shift lever. Also note the very nice loop-and-stop treatment for the brake cables, as I did on my own bike Niles.

"Hellenic" (Dan calls them "continental") stays, seat lug/sleeve, and "where did it come from?" rear brake cable stop. A bit further down, that's the mount for my generator-powered taillight.

Rear brake cable hanger. Might be prone to flexing (thus mushiness), and it's brazed to the thin butt at the top of the seat tube. Pump pegs on the outside of the seatstay might cause the pump to block a bit of light from the taillight.

Fillet brazed bottom bracket area, fender mount braze-on, and thoughtfully indented seatstay for big ring clearance.

Very interesting dropout treatment and slapguard braze-on. Seatstay doesn't follow the angle of the dropout.

A better look at the seat lug/sleeve, which follows the contour of the fillet.

Fender mounting point and rear Mafac braze-ons.

The front dropouts also have interesting attachments. And the big dropouts are striking—and appropriately "English-looking," given the heritage of the fork blades.

A look at the bend of the fork blades. Also English-looking to my eye.

The lovely fork crown, onto which the Mafac bosses are attached. I sent Dan a front rack made by Mike Barry of Mariposa. It looks like I'll need to use a fairly large spacer to have it sit level. I might try making another rack myself...

Big loops for the generator wires on the left fork blade.

Dan's lovely custom quill stem. I still need to add a bell mount and put a cable stop for the front brake. I think I'd like the stop right in the extension, so that the brake cable passes through the stem. Not a very popular design for some reason—maybe because raising/lowering the stem affects the brake action, though that's not a big issue for me; and might even come in handy if I needed to drastically loosen the front brake for some reason...

A look at Dan's unique flush mount of the quill bolt.