Internal nipple rims
Internal nipple rims and standard rims differ in the way the spoke nipples are seated on the rim. In internal nipple rims, the nipples are inside the rim cavity, which can potentially provide better aerodynamics, possibly a stronger rim structure and greater longevity of hidden spoke nipples. However, all these benefits come at a price. As it happens, both, first time wheel assembly and later ease of maintenance are greatly hindered by such a rim construction. And if replacing a broken spoke or just some basic truing & tensioning is performed, no harm done, a wheel builder might not even bother about the additional time spent on the rim. On the other hand, when lacing a wheel from scratch, an internal nipples rim construction will inevitably make the overall assembling process of the wheel much more complex and challenging. And with that, most likely discourage a novice wheel builder in the first place from arranging a wheel building project using such rims.
Not only first time lacing of the wheel, because of hidden nipples, the overall ease of maintenance can be a real fallback of such rims as you have to always remove tyre to perform any spoke nipple adjustments.
Having encounter internal nipples rims just recently, a nice opportunity for an article appeared. From the start, knowing I will be using both internal nipples in combination with eyelets on such deep profile rims, made me grunge a bit. Getting all the components, spokes, nipples and eyelets included, I just needed proper tools to start lacing the wheel. Let’s now look at my lessons learned (some of them the hard way).
Tip #1: Tools for inserting internal spoke nipples
Inserting a spoke nipple through the rim bed is pretty straight forward and as such was not even that much of a question from starters. Being a standard spring-based lacing tool from Unior or internal spoke nipple key with square head that I had from Birzman - it made no difference. Both tools held onto the nipples nicely and I was sure no nipples will get dropped easily. One aspect covered.
And now fast forward to the more interesting part. The main concern for me was how to insert both internal nipples and eyelets included by the manufacturer at the same time. Continue reading the next tip for more information.
Tip #2: Adding eyelets to the setup
As it happens, usually it all comes down to tooling used. And here comes the trick. We need a guide when inserting both spoke nipple and eyelet through the rim. To do the job, you can basically just cut a spare standard round shaped spoke in half with threading left untouched. In that way, threads can serve as a guide when inserting a nipple-eyelet combo inside the rim bed. Such spoke gadget tool just has to be long enough to reach through the rim profile (height). Ok, but why stop here if we can take things to the new level, huh? Basically, I found and modified a small manual drill holder to hold this spoke. Speaking from experience, I just love chances, where ideas for custom tools appear.
Using such a gadget tool made from a spare spoke, first protrude it past the rim wall and thread one piece spoke nipple and underneath place a washer. Now position the eyelet – nipple combination by simultaneously pushing the spoke key through the rim and pulling the spoke on the outside of the rim. Once done, continue pressing the spoke key with the nipple and eyelet, and gently unwind the spoke thread from outside of the rim. Keep steady hand while inserting a real spoke from the wheel hub. And that’s it. A small comfort here, once you practice it a bit, less and less nipples will get dropped inside the rim.
Tip #3: Preparing nipple holes
To make a rim structure as strong as possible, manufactures obviously tend produce rim holed using drills which are usually on the small side. And as it goes with the nature of carbon fibre, it might happen that such holes won’t be completely clean of any debris which may prevent a smooth lacing of a wheel. Failing to perform this step, and lacing the wheel will become much more time-consuming as you will have a harder time inserting spokes from the outside while at the same time, your chances to drop eyelets will improve.
Using the same home-made tool as presented above, I found that just protruding couple of times gently through the rim wall using spoke thread, will make rim holes clean again and ready for inserting spokes.
Tip #4: Lost eyelets & nipples
Hoping for the best but preparing for worst. Take your time and hold your hand as steady as you can when pressing the spoke nipple & eyelet combo against the inner wall of the rim. However, be prepared to drop some nipples or at least eyelets inside the rim.
While you will probably have a harder time catching alloy / brass nipples, you could fetch washers pretty easy using a magnet stick from an internal bike routing kit. Or any other, as long as you can reach inside the rim for the stainless washer to stick onto it. Nothing worse than that metal rattling sound inside the rim, right?
Tip #5: Free your hands!
Maybe the best tip of them all - free your hands using a wheel lacing stand. If possible, try to fixate the rim and the hub on some sort of stand so you can easily lace the wheel using both hands for lacing only. Learn how you can create one using my template as presented in the article Wheelbuilding stand - DIY guide to a tool pro wheel builders use. When dealing with internal nipple or tapeless rims, when there is no other option just to use both hands for lacing a wheel, such stands are worth gold!
Bonus tip: Counting threads, but how?
Maybe you are used to count threads when winding spoke onto the nipple when assembling a wheel, so every nipple is mounted onto the spoke evenly before taking the wheel to the truing stand. At least I know I am such a person. So, how could you replicate such practice on hidden nipples? As for me, in the first phase, which included just winding nipples onto the spoke, I threaded each nipple to the point, where the end of the thread on the spoke got lost in the rim. Once I was done with lacing the wheel, I repeated the process, but now, instead of watching closely each spoke, I counted a specified number of turns and repeated it around the wheel. Only then I moved to the truing stand with at least so-so laced wheel. This practice could be refined with some gadget tools, but at least, it helped.
Final thoughts
Internal nipple rims can be a bit more challenging to maintain compared to standard rims. Because the nipples are located inside the rim, adjusting or truing the wheel requires access through the rim bed. This inevitably means you might need longer tools or specialized equipment to reach or position nipples. All in all, the maintenance process is slightly more complex and time-consuming, compared to the standard, external nipple rims. However, with tips and tricks presented in the article, hopefully you should be able to optimize the workflow and save some time. Or at least won’t get discouraged from lacing such a rim in the first place. Anyways, happy wheel building!
About author
Aljaž Trenta
Author and founder"As a cycling enthusiast, bike mechanic and self-taught web designer, combining several of my passions and skills to build SpokeCalc was a great fun for me."