All those Nipples and rims

In a precedent chapter we talked about how much we like Head Driven Nipple. That's mostly for constructing wheels with adapted and "stantard" rims, where you choose convenient parts.

When dealing with reperation or rebuild of wheels you come across ALL the nipples and rims there is... There is at least 10 to 15 kinds by brands, and all those chinese no names. That's a lot of possibilities.

Here are some rules of the thumbs about the choices of nipples.

Brass are for strong, heavy loaded and salty road - winter or beach riding. They are also cheaper, so I use them for entry level wheels for city bikes.
Aluminium nipples are for lightweight setup.

Rim holes should be 0.3 to 0.6 mm wider than the body diameter of the nipple. It is to allow a direct path of the spoke to the hub holes. Which means than a standard DT Swiss or Sapim nipple with a body diameter of about 4 mm will fit 4.3 to 4.5 rim holes.

When dealing with oversized spokes or oversized rim holes you need to take this rules into account. Most of the time you will find a solution with a Sapim nipple dedicated to this tasks.

You can also drill the rim - without eyelets - to the right size you need to fit the nipple you want. For example, Pillar make nice 13G nipples with a body diameter of 4.3 mm that need a 4.7 mm drill. For an Oversized Sapim nipple of 4.9 mm of body diameter, you will need to drill at 5.3 mm, and so on.

In the case of oversized and non standard Nipples and rims you will be faced with non standard ERD for spokes calculations. As always you will need to measure the ERD on you rim before calculating the spokes lenght.

All those non standard nipples are different and you should test how they fit on a spoke before calculating. Remember that your spokes should be long enough to support the head of the nipple. But without interfering too much with the end of the thread on the spoke - when you can no longer screw the nipple to the spoke. Biting the end of the thread on the spoke is okay for one or two turns, but not more. With fewer threads between the spoke and the nipple you will lose strenght in the connection between them, the nipple might pop out of the spoke.

For measuring ERD with non standard rims and nipples, you adapt your ERD measuring rodes with the non standart nipple you want. For rim with oriented holes : measure the inside diameter of the wheels and add what is missing by marking the part of the nipple leaving the rim and measure to where you want your spoke to stop.