Archive for December, 2013

11
Dec
13

The Fork-a-lizer

Oh the brain cells are constantly engaged over here in the Bike Bunker, always thinking up better and more entertaining ways to wrestle tubing into the shape of a bicycle.

Case in point: the Fork-a-lizer, the latest, greatest, and most elegant method for copying the geometry of a bicycle fork ever conceived by a shade-tree mechanic. Personally, I ascribe this particular flash of Near Genius to the fact that I got a tetanus shot this week. Strengthens the corpuscles in the brain while rendering one impervious to the maladies of the metalworker, such as the dreaded lockjaw.

Now you may ask yourself “Copy the geometry of a bicycle fork!? Why would anyone ever¬†want a tool to do that?” The answer to that infinitely rational line of questioning is rather prosaic: I don’t have the tools, time or the training that is necessary to come up with The Next Great Thing in¬†bicycle fork design. Sure, down the road it may make sense to play around a bit, but for now simply copying a design that I know will work is both expedient and, when you are laying out your own cash for tubes and fork crowns, economical. Plus, with a grand total of two bikes under my belt and a third one now underway, it’s not like I am Richard Sachs or Irio Tommasini. I’m just an idiot who builds bikes in his garage. A deliriously happy idiot, but an idiot nonetheless.

Hence, the need for the Fork-a-lizer.

The concept behind the Fork-a-lizer is relatively simple; it is an adjustable jig that you can set up to produce a straight legged fork that matches the specs (height, rake) of fork that you wish to copy. You pop in the fork that you wish to copy (1 inch steerer tube for now) adjust the two set screws under the steering tube so that the tube rests upon both of them, and line up the brake hole in the crown with the adjustable pin that sticks up from the Fork-a-lizer body. Those are the settings. Now you remove the fork that you are copying, pop in the steering tube and crown of the fork that you are building, line up the brake hole in the crown with the adjustable pin, cut the fork legs to the proper length, and you are ready to rock.

Bonus feature: the finish on the Fork-a-lizer is heat resistant (i.e.. I had a can of barbecue paint laying around).

A couple of caveats. The “adjustable locating pin” is only sort of adjustable. I have it located so that it makes a fork with a axle-to-brake-hole height that works with short reach road brakes. If I was going to make a touring bike and wanted a fork that would fit fenders or clear fatter tires, I would need to move the pin to create more clearance. I made the pin removable if I wanted to make a fork with more clearance. I have some ideas on how to deal with this on the Mark II version of the Fork-a-lizer.

Does it work? Damn straight it does. It makes the pretty girl very happy.

The Fork-A-Lizer, now available in fire-resistent black.

I still haven't cleaned my workbench.

In warm weather that helmet smells like a dead animal.

I have a lot of C-Clamps laying around my shop.

Voila!

Those are some damn fine joints.

Flowers!




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