Locking B*ke Freewheels

Unicycles and Equipment
1

Anyone have experience disabling a bicycle freewheel so that the gearing is direct like a giraffe would be?

I saw the Picture of George Barnes’ Girafe ( http://www.unicyclist.com/forums/showthread.php?s=&threadid=33867 ) made out of a bike frame, and I have an oldish trek mountain bike with a bent fork, and was wondering if it would be relatively easy to freeze the freewheel and atach a saddle to make it a giraffe.

P.S. Welding is probably not an option… I don’t have the skills or equipment.

2

What you do is remove your freewheel then you can buy a single sprocket that threads on the same threads and a lock ring and get the threads clean then use plenty of red locktight. These sprockets and threaded lock rings are for fixed gear track bikes and it’s the way that most giraffes are built. You could get the sprocket and lock ring from unicycle.com. The ones for bikes are smaller than you would want for a giraffe, you can probably get a twenty six tooth sprocket from unicycle.com. I dont know of a way to lock up a freewheel and without a lockring it would spin right off. The above setup will only work on an old style removable freewheel not the newer cartridge type.

3

Here’s a link to Sheldon Browns ‘fixed gear’ bike page, with links to pages on converting bikes to fixed gear.

4

I welded the cheapo steel hub on the giraffe in the picture. Welding may be cheaper than buying a fixed hub, even if you have to pay to do it. It’s obviously not an ideal solution (but it was very cost effective!).

5

Thanks

Thanks everyone… that might end up being my next project.

6

In general, the lockring approach is not reliable. I have had one success for light use and one failure for heavy use. Red loctite, standing on the wrenches, and jumping on the pedals were all unsuccessful in the latter case. For your project, you might consider the welding approach; any local welder would do it for a few bucks.

7

I’d go for the welding option if I were you. If the locktite fails while you’re riding the giraffe, the resulting fall can be very sudden (and painful). Personally I’d trust a welded giraffe a lot more than a locktited one.

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