Topic: Advice on drilling a Borrani rear rim?

[blackhog02]

I took the rear wheel to the local shop and had the tire taken off the rim.  It looks like most of the spokes are at an angle http://forums.sohc4.net/index.php?topic=47506.0   so I figure it is time for surgery but I don't want to mess up the rim.  Has anyone else drilled out the spoke holes on a Borrani rear rim to make it work with a stock cb750 hub and if so how did you do it?  I'm thinking that I need to get a drill bit the size of the existing hole and try to ream it out at a better angle???   Any recommendations on technique, drill bits, etc?   

I took a closer look at it and if the spoke and nipple are lose they will line up.  When you tighten up the spoke and the nipple seats into the dished out part of the rim (where the rubber rim strip goes) that is when the angle goes awry.  So it looks like I need to drill out one side of the dished out part of the rim so that when you tighten eveything up the nipple seats into the rim at a diffrent angle? 

[fishhead]

I have, Years and years ago.
  I made a reamer type of thing that would fit over the spoke (hollow in the center-to use the spoke as a guide) and the outside was fluted and shave the holes to the new specs. I think I used a drilled out nipple and put flutes on the outside of it(it was then welded to a rod to put in my drill).
 I had to lace up the rim loosely and ream about 10-12 of the holes and then semi tighten up the 10-12 to get the rim very close to what I needed and the rest were then reamed.
 I chose to do it this way because 1) estimating the angle could ruin the rim if the angles are off slightly 2) the drill bit will want to follow the hole that is already in the rim 3) seamed like the best way to do it (the holes will be drilled to the correct angle because the spokes are being used as a guide for the new angle).
 

[blackhog02]

fishhead,

Yah that is my concern as I don't want to make the rim worse.  Sounds like your tool would work just not sure I can make something like that.  What about grinding down one site of the nipple???  Seems like that option would be less risky to the rim as long as 1) the nipple would not spin the oppiste way when you tighten it up and 2) you don't take too much material out of the nipple and weaken it so that the nipples start braking instead of the spokes.

[fishhead]

No, leave the nipples alone as there is no guarentee that the side you have modified will sit where it needs to sit.
 You have to get new spokes and nipples, dont you? (the original thread shows a few broken spokes). You will have all the old spokes left over and you could make a "reamer" out of 1 of the old nipples.
 Drill through the nipple (only enough to get rid of the threads, as the spoke will act as a pilot for the reamer to get the new angle correct). You can put flute(s) on the nipple with a hacksaw and file the nipple down to where the flute(s) resemble a drill bit (where the sharp edge is the highest part of the "reamer").

[blackhog02]

I'll give it a try and see how it works!