Sapim Polyax 5.5mm Nipple + Velocity A23 = Tool Trouble

[JN2Wheels]

I'm hoping someone has used enough wheelbuilding tools to help me out here...

After some nipple rounding issue in a powertap Sl+ / A23 build (1x DS 2x NDS), I decided to rebuild with a A23 OC rim and Sapim Polyax nippples. The previous build was great, stayed true for over 10,000 miles without touching it, but I decided to switch to the new off-center rim and use the standard rim for a matching front wheel. The details aren't important.

This issue is this. I want to build the wheel using the 5.5mm Hex head of the Polyax nipples. The tool I have, the Park SW-15 three way, is just a tad too wide for the diameter of Velocity's inner rim spoke holes. I can't access the nipple head with my tool! There is plenty of metal meat around the socket in this tool, leading me to believe it could be narrow enough to fit.

Is there another tool that has a narrower outside diameter? DT swiss, sapim, and pillar all have hex head nipple options that call for a 5.5mm wrench. Seems like a huge error on Velocity's part not to make their inner holes wide enough for a standard 5.5mm tool, requiring a build entirely from the outside.

I don't want to build with the standard square flats, as aluminum will start to round at the end of tensioning, making later adjustment a touchy thing. And I love that the polyax nipples don't have slots for a flathead on the back side, eliminating the stress risers those create in the nipple head. I really want to build with them.

Any tool suggestions?

[crohnsy]

Sounds simple enough to grind your tool to fit...

What's the size of your hole and size of your tool?

[JN2Wheels]

Good call. My caliper shows the hole is 8.1 mm and the tool is 8.3. It seems like it should go, but no. I'd grind it, but don't have a bench grinder. And would rather get an appropriate tool, if one exists.

If anyone has a 5.5 mm hex nipple tool, other than the park, I'd love to know the o.d. ? 8mm or slightly under and I think I could get it in.

[thisisatest]

Almost every internal nipple tool I have is ground on the outside, for just this reason. Can't remember if the Mavic Cosmic tool is 5.5mm, but it is the thinnest wall.

[JN2Wheels]

So I ground it down a bit, and made it work. However, the plan to build entirely from the backside of the rim is foiled. The a23 rim is too pointy inside. When the spokes got up enough tension to pull the nipple tight on the spoke bed, the hex tool can no longer get in deep enough to get a grip on the spoke head. Drat.

[ergott]

Just use regular nipples. What are you trying to gain here?

[nhluhr]

I don't want to build with the standard square flats, as aluminum will start to round at the end of tensioning

You're doing something wrong. Ever consider lubing your nipples?

[bm0p700f]

+1 also use a sapim spoke key it holds alu nipples better so no rounding. The park spoke keys will round alloy nipples sometimes hense I use the sapim key on alloy nipples. Lubing the nipples elimated most round issues. 3 n1 oil is sufficent.

[JN2Wheels]

An Update...

ergott, I used the hex head nipples as I wanted to bring the build up to final tension from the back side and reduce the risk of deforming the nipple flats. I also very much like the solid nipple head... without the slot for a standard flat head nipple driver. Stronger. When nipples fail, they do so at the head (usually because the spokes were too short and didn't extend far enough up to reinforce this zone.)

I'm not doing anything wrong, and did lube the nipples.... Used Jeremy's (alchemy) spoke prep for the threads, and a light oil on the nipple-rim interface. Also used Jeremy's bladed spoke holder. Nonetheless, on previous builds, the final tensioning deformed 2 or 3 nipples just enough that they needed a little pliers love to reform.

Post build...

Crazy enough, on the OC A 23 rim, I was able to build from the top, as the inner-rim profile left room for the socket driver tool. Spoke tensions are soooo much closer to even! Wow. 1x DS and 2X non-drive side, led to 100 on DS and 80 on NDS. However, the rim itself proved a bit below the quality I was hoping for, with some issues at the sleeved joint. Ultimately, although the tensions are more equal from side to side, there is more variability than I would like. Ohh well.

Also, as a side note, these rims are quite effected by tire pressure. They lose 10-15 Kgf when tires are installed at pressure. This is helpful in getting that extra little spoke tension without risking nipple damage, but be careful not to tighten things up so much with the tire installed, that taking it off bumps up spoke tension close or beyond the A23s 120 Kgf limit.

I built to 95 Kgf front (radial 24 cx-rays on a White industries F11), and 100/80 for the rear (24 cx-rays, 1x DS and 2x NDS to Powertap SL+)

Thanks for the help, all.

[ergott]

Get a 4 sided spoke wrench. I've never deformed a nipple at any tension with one. The old 3 sided Park wrenches are junk. In fact, I do a lot of work with anodized alloy nipples and don't even mar them with the right spoke wrench.

The strength of the alloy nipple is in engaging the whole nipple head. If that is done, you don't have to worry about the slots for the nipple driver.

What are you using in between the alloy nipple and the rim?

[JN2Wheels]

Four sided wrench sounds good. I am using a three sided park. Sounds like I'm due and upgrade. Is there a particular wrench you prefer?

Must say, I don't use nipple washers. Thought that was more for spreading the load on fragile carbon rims. I oil the nipple before I seat it. Do you use them in all builds?

Also, a last word of warning for building with the USA made A23s. The sleeve at the joint impacts two spoke holes on a 24 hole rim. It adds about 2mm to spoke length, so I'd use the next length from Sapim if your lengths are precise, or you may end up quite short.

[ergott]

The DT Swiss/Spokey is nice. Park now makes a 4 sided wrench, but I haven't seen it up close.

I wasn't referring to washers. I've used oil in the past, but think that grease is better when you are at tension. I put some on the shoulder of the nipple before I put the nipple in the rim.

You are correct about the sleeve and it's been that way since before they were made in the US. I did have a few rims that were drilled into the sleeve deeper so the nipple seated correctly, but not all of the rims. I've used a 1/4" spade bit on a hand drill to countersink the hole more if it's really bad.

[JN2Wheels]

Thanks for the advice! Next wheel build will be that much smarter.

I rode the wheelset last night at our local Tues Night Worlds. Quite a few 1000+ watt surges, and 40 min of the 2 hrs at 250+ watts. No adjustment needed. They are solid.