Danielvetpath

Hi:

Building a set of Light bicycle ar375 rims with Carbon-Ti hubs, straight pull, 24 spoke. They recommend alloy double square nipples. I have never used double square nipples before. My usual supplier for wheel parts stocks 16 mm long (equivalent to 12 mm traditional spoke) double square nipples. Is this appropriate? Spokes will be CX ray front and non-drive rear and CX sprint drive side rear.

Thanks for any input,

Daniel

FBinNY 

Nipple length only matters to the extent that it must reach through the rim to allow alignment via the wrench flats. Long nipples are a throwback to the days of wooden rims, and rarely beneficial today, except to OEMs who find it speeds lacing.

Regardless of nipple length, the spoke must reach through the button head. It is not necessary to reach the top of the square, unless thread engagement demands it.

Dan Burkhart 

If you want a general rule of thumb, which in this case I have found to be quite reliable, adding 2 mm to the spoke length as calculated for standard nipples works for double square.

FBinNY 

With sincere respect to Dan, double check thread length before increasing spoke length to beyond the top of the button.

If the nipple barely allows spokes to the top of the upper square, targeting it that high severely limits the working tolerance.

Dan Burkhart 

Of course for maximum accuracy, the OP can always measure ERD with spokes terminated at the desired position in the double square nipples.
Optimum benefit of building with double square is achieved using an internal nipple wrench, but if only building one set of wheels it's hardly worth buying another tool as a conventional key works the same as with standard nipples.

Duragrouch

I didn't know what "double-square" was, but I guessed right when I looked up. Looks like it's to allow using a T-handle wrench on the nipple from the end (gripping 4 sides), instead of just a normal spoke wrench gripping 2 sides, so less likely to strip on the nipple. Yes? I think I'd like. Could not use on my cheap single-wall rims, would stick up too much, but should work great on double-wall rims.

BTinNYC 

These double ended nipples are necessary IMO when building up an aero tubeless rim. Needs the T handle and the flat-spoke holder.

And don't drop a nipple inside the rim...like I did. Took longer to get it out than it did to lace the rim.

FBinNY 

A trick to building deep section rims.

Use a wooden toothpick in a pin vice to pick up nipples and spin them a few turns onto the spokes. Note, it might be necessary to break the tip off if it goes in too deep.

FWIW, I use this method 100% of the time because my fat fingers are unsuited to lacing wheels.

BTinNYC 

is how I got the little SoB outa there!

Duragrouch

Now see, there's another reason for double socket/eyelet rims, couldn't happen with those. But they add weight.

Duragrouch

I could see having a hard time rotating it to drop the nipple out. I would shape the end of a popsicle stick to sorta match the inside of the rim, poke it in the rim at about 3 or 9 o'clock, rotate the rim until the nipple stopped at the stick, pull it out. (Unless the clearance holes on the inside of the rim are super small, just big enough for a nipple wrench, which I could see if that is where the tubeless seals with a cap, and not at the spoke nipple. I dunno, I've never run tubeless on bikes.)

FBinNY 

Carch-22

While double eyelets would solve the dropped nipple problem on deep aero rims, the depth that causes the problem also makes double eyelets problematic.

In any case, dropped nipples are just part of the learning curve. It's easy enough to prevent, but you have to experience it once to get to the "Gee, that was fun, but not again" stage.

Duragrouch

I did that in unscrewing the wrong bolts to take the retracting guard off a chop-saw, unwinding the coil-torsion-spring. Took 90 minutes, multiple tries, to get it back together. I then clearly labeled with sharpie, what screws to NOT loosen, and which TO loosen, to change the blade. Get call a year later from saw owner, their ex, despite clear instructions, took out the wrong screws, did I have any advice? With multiple people holding various tools, they were able to get it back together.

BTinNYC 

I don't think double ended nipples come in very different sizes. Some mfgrs are at 14mm, some at 15, some 16, and that seems to be about it.

Dan Burkhart 

This is the tool I made for the job. A spoke bent into T wrench configuration with a nipple forced past the bottoming out point so there’s a few mm protruding. Put an end to nipples lost in the rim.

79pmooney

+1 Only I go silver and start the nipple in the other direction. I've got two, one 14g and one 15g. They are so fast and easy to make (and cheap!) that they never run off and hide. This would be more of a challenge with a deep rim where you cannot access the nipple flats from the hub side and need to get the wrench on to unscrew this tool. (Speculating; I'm still in aluminum tubed dinosaur mode.)

FBs trick has the straight pull out advantage. (I had to look up pin vise. Looks like my sewing awl would do nicely.)

Dan Burkhart 

The above tool only works for standard nipples that can be accessed on the hub side and I only use it for extreme deep rims like 86mm or more.
the vast majority of those deep rims I build with hidden nipples and insert the nipples with a wrench.
​​​For standard depth rims I use a nipple insertion tool that looks a bit like an awl with a bearing on the end to spin in the hand