Sapim Polyax 14 Gauge Internal Locking Inverted Silver Brass Nipple
The Sapim Polyax internal nipple is the version of the Polyax for rims that hide their nipples inside the rim cavity: an inverted brass nipple that is fitted from inside the rim before the tape goes on and turned with an internal nipple driver, with the same rounded seat that lets the spoke run straight and a locking compound on the thread so it cannot back off where nobody can reach it. Sapim makes it in Belgium in 14 gauge, silver brass. The Polyax internal is the nipple for aero carbon road rims and some mountain rims that use internal nipples for aerodynamics or bed strength. This page covers the Sapim Polyax 14 Gauge Internal Locking Inverted Silver Brass Nipple.
We sell Polyax internal nipples only as part of a wheel we build. Choose your rim, hub and spokes in the configurator and the wheel ships from Georgia laced, tensioned and trued by hand.
Design and construction
A spoke leaves a hub flange at an angle and arrives at the rim at a slightly different one, and on most rims the nipple hole is drilled straight through, so a conventional nipple sits square to the rim and the spoke has to bend to meet it. The Polyax seat is a section of a sphere; it rocks in a matching countersink or against a washer until the spoke is straight, and the load passes through the nipple in a line rather than at a kink. Sapim also puts a thread-lock compound on some versions and cuts the threads to run smoothly on its rolled spoke threads.
How it rides
A wheel built with internal Polyax nipples on a Polyax-compatible rim looks cleaner and, on a deep aero rim, is a little faster, and the locking thread means it stays true without access to the nipples. The trade is that truing needs the tire and tape off and a driver through the rim bed, which is why we build these wheels to a tighter tolerance and stress-relieve them twice before they ship.
Specifications
| Material | Brass |
|---|---|
| Type | Internal |
| Finishes | silver |
This version
Version notes: brass, 14-gauge, standard-length, with a locking thread. Brass is the one to choose for durability, salt and carbon rims; it does not corrode, does not round off and turns in a spoke wrench a decade later. It is the heavier option by roughly 30 grams a wheel, and that is the whole of its downside. Brass also deforms very slightly as it seats, which lets it bed into the rim bed and sit square, and it is far more forgiving of a spoke key that is a size out or an owner who tensions a wheel without much feel. Unless a build is chasing grams or a specific color, this is what we fit, and it is what we fit on every wheel that will see winter.
This one is the internal, inverted head: it is driven from inside the rim bed with a square driver rather than from outside with a spoke key. Rims with no external nipple access need it. Budget extra build time - every adjustment means getting to the nipple through the rim, which is why we charge differently for building on internal nipples.
Sizes, fit and compatibility
The Sapim Polyax 14 Gauge Internal Locking Inverted Silver Brass Nipple fits any 2.0mm-threaded 14-gauge spoke and any rim designed for internal nipples, such as the Nox Falkor and some ENVE and Reserve road rims. The configurator fits it automatically when you choose an internal-nipple rim.
How Sapim makes its nipples
Sapim's Polyax head is the part worth understanding. A spoke almost never leaves the hub at a right angle to the rim; it arrives at the nipple at a slight angle, and with an ordinary nipple that angle has to be absorbed by bending the spoke right where it is weakest, at the thread. The Polyax head is rounded so the nipple can sit at that angle instead, keeping the spoke and the nipple in line. It is a small piece of geometry that removes a stress riser from the most common place spokes break.
Washers matter more than people expect on carbon and on thin-walled rims: a concave or flat washer spreads the nipple's load over a wider area of the rim bed and lets the nipple seat square. We stock the Sapim washers alongside the nipples because on some rims we will not build without them.
The manufacturing detail above comes from the maker. The choice of nipple for a given build is ours, and we will explain it if you ask.
Building it at ProWheelBuilder
Sapim makes the Polyax internal; ProWheelBuilder is an independent wheel builder in Georgia, not the manufacturer. Spokes are cut from the ERD we measure on the actual rim, the wheel comes up in stages on a tensiometer, and it is stress-relieved and trued before it goes in the box; tape and a valve go on if you ask.
The configurator filters to what fits, crosses out what is not made, and prices the build as you go.
Warranty
Manufacturer's warranty. Sapim Nipples warrants this product against defects in materials and workmanship. The duration, conditions and claim process are set by Sapim Nipples and can change without notice, so ask us and we will confirm the current terms before you buy.
ProWheelBuilder. Lace this into a wheel here and the finished wheel gets our own one-year warranty as well as the maker's. For twelve months we replace broken spokes however they broke, and the work on the wheel is on us - truing, re-tensioning, a rebuild where it is needed. If the rim or hub is covered by its manufacturer we put the claim in and chase it; if it is not, we supply an eligible replacement rim or hub at 25% off the current retail price. Carriage both ways is the customer's, and this does not cover wheels built from parts you send in.
Full terms are on our Policies & Warranty page.
Polyax 14 Gauge Internal Locking Inverted Silver Brass Nipple questions
Do I need internal nipples?
Only if the rim gives you no way to reach a nipple from outside the rim bed. Plenty of deep carbon rims are drilled that way. They are driven from inside with a square driver, every later adjustment means getting at the nipple through the rim, and a build on them takes longer - so choose them because the rim requires it, not for the look.
Which rims use internal nipples?
Deep aero carbon road rims and a few mountain rims, where hiding the nipple inside the rim improves aerodynamics or bed strength. The configurator knows which rims need them.
How is a wheel with internal nipples trued?
With the tire and tape off and an internal nipple driver through the rim bed; we build these wheels to a tight tolerance and lock the threads so they rarely need it.
Why a locking thread?
Because the nipples cannot be reached once the tape is on, the thread compound stops them backing off under vibration.
Brass or alloy internal Polyax?
Brass; internal nipples are not the place to save grams, and brass does not round off under the driver.
Do the nipples match the rim?
Yes. The configurator only offers nipple types the chosen rim accepts (external or internal), in the finish you pick.
Not sure? Text or leave a voicemail on 470-253-0929 or email info@prowheelbuilder.com — you will be talking to the people who build the wheels.
