Hobbit Forks on a Moby

Revision as of 00:30, 24 January 2009 by Carpy (talk | contribs)

SAFETY EDIT: READ THIS BEFORE PROCEEDING! The nub I used in this procedure as a brake stop is not attached strongly enough to the fork to be used as such. Instead, weld a new brake stop lower on the fork so it lines up with the motobecane brake hub, or proceed as described here and just weld on the nub so it is solid. This is necessary to prevent a potentially dangerous "I thought I had front brakes....oops!" situation. I will post pics soon and update this description for the alteration. Ok, the rest is still valid, read on! --Julian

Ok, so here is a bit of a guide for anybody interested in adapting hobbit forks to a moby. I know this has been talked about a lot and the details are out there, but everybody loves pictures! However these pics aren’t the best; I have an old camera, a dark basement and no tripod at the moment.

So to start with, the forks fit in the moby head tube perfectly. I tapped the moby bearing cups out and pressed the hobbit cups in, and used the hobbit bearings because they have ball retainers that make life easier; the moby bearings are free to hit the floor and bounce into the corner.

Making the forks fit the frame literally takes 15 minutes once the moby forks are off.

1. Tap out moby bearing cups
2. Tap in hobbit cups
3. Clean and grease bearings, insert into cups
4. Insert hobbit fork, bolt on and tighten head tube nut.

The minor trickery comes in at the wheel, as there are a couple problems. The motobecane brake hub has nothing to stop against on the hobbit fork; The hobbit forks are a bit narrower at the axle, so you have to remove a nut to fit it in, but then the wheel is off center. There is a nub on the hobbit forks that hits the wheel. This is easy to solve; 1 minute with a grinder takes this nub right off.

So to start with, get a rear brake hub from a donor motobecane.

The brake stop on the rear brake hub is almost a perfect fit, but not quite long enough:
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So get a piece of 3/16” x 1.5” x 1.5” flat stock, and cut a 1/2” wide 5/8” deep grove in it. This will be the brake stop extension:
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TIG weld the extension to the original stop:
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Now to get the wheel centered on the axle, it is necessary to cut down the brake hub stop about 3/16” to 1/4”:
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Grind, prime and paint:
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Bolt it all up:
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Sit back and bask in the glory of the Man in Pink:
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