tendency

I know aluminum on aluminum is typically not recommend however is it really a no-no? Anecdotally, two of my favorite wheels, that I've ridden 20 YEARS were both built with allow nipples on aluminum rims (neither of these I built). 0 issues with either. What are all your opinions on this? Now that I've started learning how to build my own wheels should I stick w/ the recommended brass nipples? Thanks for input.

HillRider

Aluminum on aluminum is not a problem. It's dissimilar metals (aluminum on steel, carbon on aluminum, etc.) in contact that causes problems with electrolytic corrosion. The classic example is an aluminum seatpost stuck in a steel frame. Aluminum components, particularly aluminum nipples, have a problem with wet/salty conditions such as riding through Northern winters where the nipples corrode and break. Ridden in relatively dry conditions aluminum nipples are fine. That said, brass is stronger and more weather resistant at a very minor weight penalty.

tendency

Ah, I did not know that - thanks HR!

DiabloScott

Aluminum nipples for light weight, dry weather wheels; nice choice regardless of rim material.
Brass nipples for wet weather - they will also hold up better to a spoke wrench.

Andrew R Stewart 

Al makes for a poor bearing surface. A spoke nipple that is intended to be able to be turned in the future is just a bearing that isn't yet being used. Al likes to gall when pressed hard and moved against another Al piece. Then there's the corroding and weaker (than Brass) strength, only furthering the possibility of cracking or rounding off a nipple after a few seasons of exposure (sooner if there's salt about).

The only couple of Al nipples wheels I have made for myself were front ones where the future truing needs are usually FAR less than a rear wheel's. All my current bikes have brass nipples. Andy

Steelman54 

If you must save weight or have been lucky, great. Aluminum is a great material but a poor choice for a nipple as it is prone to galling (mentioned above) and stripped threads in the hands of inexperienced users/wheel builders/wheel truers (is that a word). Stick with brass for most applications. Just my opinion.

KerryIrons

Yup. Pretty much sums it up.

cyccommute 

Galling isn’t going to be an issue if you are talking about the aluminum nipple moving against aluminum rim. The surface area is large enough that the nipple will easily break free from the rim if gauling happens in that situation. If the aluminum gall in the threads that can be a problem but that’s why spoke prep and oil are used during the build. Dry spokes and dry nipple will lead to issues…no matter what metal is used for the nipples.

Again, spoke preparation and oil go a long way to keeping that from happening. I will agree that rounding of the spoke nipple is an issue but we shouldn’t be using square spoke nipples even in brass. At at least don’t use the 3 sided spoke wenches. The 4 sided spoke wrenches like the Park SW-42 do a much better job on any spoke nipple

I don’t like 4 sided aluminum nipples because they are easy to round off. I’ve never had a galling problem but I always use spoke prep and oil. I have been using splined spoke nipple for about 15 years and never have had a problem with adjusting a wheel no matter what the age.

Andrew R Stewart 

When i reply to these posts here i am often speaking more from my shop experience than from my personal practices. I do agree that with best practices alloy nipples can work well enough, I alsao apply a spoke prep before lacing a wheel and a tab of oil on each nipple (actually at it's both ends and about the head/rim contact). I also agree that spline wrenched nipples are less likely to wrench strip. Although the industry seems to not feel that the cost is worth it as nearly no bikes come that way and most all after market wheels don't too.

WRT the nipple galling on the rim- Perhaps I didn't fully explain what i was trying to describe. Al nipples on an Al rim, without any spoke hole eyelets, tend to have far greater friction between them than brass nipples on Al does. It's this Al on Al friction that adds to the spoke in nipple friction and thus makes rounding off the nipple's flats all that much more likely, hence the oil applied to that contact. It's by belief that added to this is the age/exposure corrosion aspect that increases the nipple/rim bond.

It is this nipple on rim friction that I don't like to use eyelettless rims, which seem to be more and more common what's made available. Sure a good way to lower rim production costs (and at one time some rims were made with an eyeleted version and a bare one, often for the OEM market). Even with brass nipples an eyelet, usually made of a steel, will lower this friction and make after build up truing much easier.

Now if the OEM and aftermarket wheel building outfits (and I'm not meaning the custom building small "companies") were to use best practices during the wheel making and the riders didn't expose their nipples to water (especially with salt) I would likely have a better ability to true rims. Andy (and don't get me started on reduced spoke counts...)

cyccommute 

I haven’t seen too many aluminum nipples on OEM wheels with the exception of Specialized…which have their own problems. Inexpensive replacement wheels are all brass.

I build with a lot of wheels without eyelets and aluminum nipples. I’ve not experienced any kind of galling with them nor are they any harder to turn than rims with eyelets. Aluminum can’t take the same force that brass can (in square nipples), of course. My wheels are also used in all weather but. again, I haven’t had issues with making adjustments at any point.

That would be good but most people don’t want to pay $200 to $300 for a replacement wheel. Robotic builders could be programmed with the steps needed but, again, it would add significantly to the cost.

I do a lot of adjustment on old wheels at my co-op up to and including redishing. (I’m astounded at the number of poorly dished OEM wheels out there). One thing I do (or have my volunteers do) is to add a drop of oil at each nipple. It helps a whole lot. I usually just use TriFlow because it’s handy. Of course, I don’t see a whole lot of aluminum nipples.

One word on Specialized and their OEM aluminum nipple use. I’ve had numerous broken spoke nipples. They used spokes that were too short. They don’t reach the spoke slot and they tend to break above the rim. Someone thought they could save a few pennies per wheel and left us with a problem.

davidad

I don't see the need for Al. nipples. The weight savings is insignificant, and durability is questionable. I used them once and needed to tweak the wheel and they began to break.

smd4

I'm sort of a weight weenie, but I went with brass nipples for the durability reason.

KerryIrons

This is why I always put a touch of lube on the shoulder of every spoke nipple when building a wheel. The nipples turn easily many thousands of miles later. Just one more good practice to reduce friction in wheel building.

bluehills3149

I have 2 different rims that need re-spoking as the al nipples have corroded and cannot be turned so it is a lot of work to rectify - and often the spoke will break or twist before the al nipple breaks free so you can't just re-use the old spokes. In my opinion, they are one of the worst cost/gram savings you can make as rims are too expensive to justify the grams saved - that said, if you're after a rim to last a couple of race seasons, the trade-off may be worth it.
Note an al nipple weighs about 1/3 gm and a brass about 1 gm so for a 32 spoke wheel you'd save about 20gm/wheel.

tendency

What sort of spoke prep should I be doing before building up the wheel (aluminum/aluminum spokes/nipples)? I was thinking just some Park bike grease on the threads.

Andrew R Stewart 

This is one of those questions like "which chain lube should I use?" There are a few answers that are OK.

Lubes (oils and greases) are for reducing the friction during the build up and reducing the long term corrosion that makes sliding parts easier to move. For Al nipples and rims (w/out eyelets at the spoke holes) lubing the nipple/rim seat makes for an easier time to get good spoke tension levels.

Spoke Prep (the product) and other thread filling products are about reducing the chance of a nipple unwinding when the spoke's tension is reduced during riding. It also will help reduce corrosion over time but as it has a somewhat glue like quality it adds to the friction of the nipple turning on the spoke's threads.

As some here have already said either approach will aid the build up and make future truing easier. Some here have mentioned how they prep/lube the nipple contact points.

I just applied Spoke Prep to a set of spokes for a tandem wheel build (Velocity Dyad 40* rim w/ no eyelets) last night. I thin the Spoke Prep slightly with alcohol, bunch up the spokes in one hand with the ends even (I tap the bunch on the bench top to get the spokes all the same positionally) and tap the threaded end in the Spoke Prep's cap. Only the last mm or so of the threads have SP on them at this point. I'll roll the bunch of spokes about in a bunch to spread the SP down the length of the threads and no further. This results in a thin coating, I can easily see/feel the threads crests.

After I lace the spokes and only start the nipples a few threads worth I'll go back with a squeeze TriFlow bottle and add a tiny drop of lube at three points; the nipple head to both draw lube down the nipples insides and down the outside to where the nipple/rim seat is and also on the spoke at the still exposed threads.

I tension up and true/dish the wheel to completion. After i take a rag/paper towel and wet it with some Clean Streak then wipe off the rim and nipples both inside and outside the rim. This helps to remove the excess lube and reduce future grime collecting.

I have seen really good wheel builders only use grease, only use SP and/or only use oils with no real differences in the final results. But this says more about the builder than their preparation. So much like that chain lube question I see it as more a "use something" answer than which something to use. Andy

I have a friend who has been a regionally ranked racer, a shop owner and a supplier sales rep for decades. We have many similar experiences and have spent hours with a beer and talking about our industry and the various things we do in it. He mentioned that he applies a wicking LockTight to each nipple's end (w/ no other lube or prep) on his wheels. I had a cringing moment but he's the captain of his wheels so I kept my opinions to myself, just glad I would not be the one truing those wheels later