Amir Avitzur wrote:
>
> Someone recommended cutting down an allen wrench to make a cheap
> Hub Race Removal Tool. Tried it today. [snipped]
>
> Placed the Hub on a wooden park bench and took a few swings on the
> "tail" end of the wrench. But persistent swings didn't even
> budge the Campy Hub races.
A while back I told of how to make a 4-prong "rocketship" type hub cup
punch out of steel tubing - well here is my finished tool:
http://bulgier.net/
Compared to a single-pointed drift or sharpened allen wrench, this 4-prong tool drives the cup straight out. No cocking it first one way, then the other, as hitting it on one side at a time would do. I think this very much reduces the force needed - the hammer blows were quite reasonable, without even heating up the hub first - no sweat! (Though moderate heating of the hub first is probably still a good idea)
I made the shaft 3/8" so it would fit in front hubs. But the rear hub,
being a bit bigger, allows the tool to flop around a bit. So to keep
the tool centered I added a bolt down the middle, like so:
http://bulgier.net/
The bolt does two things:
(1) The shaft (thread) of the bolt is bigger than the hole down the
middle of the tool, so by cramming the bolt in, the 4 prongs are spread
a bit wider. This is good because the prongs have to spring inward on
insertion to get behind the cup, and the distance they can spring back
out is limited, so without the bolt they didn't have much punch/cup
contact area. You can see the amount of punch that can bear on the back
of the cup in this picture:
http://bulgier.net/
(2) The head of the bolt is just the size to fit inside the hole in the
cup, so it holds the punch exactly centered on the cup, check it out:
http://bulgier.net/
This tool is probably not worth making just to get one hub cup out. If
that's all you need, just use the sharpened allen wrench method, and
heat the hub up first to make the hammering easier. But if you think
you might do this operation a few times in your life, or you just like
using the RIGHT tool, this tool is a joy to use in comparison. Check
the archives for the full instructions on how to make it. If you want a
6x1M bolt to spread the prongs like mine, start with 3/8" x .083" or
.095" wall tubing, preferably 4130 Cr-Mo. I got mine from Aircraft
Spruce, one foot of .083" cost all of $2.75. and will make at least two
of these tools.
http://www.aircraftspruce.com/
Mark Bulgier
Seattle WA USA