I’ve just removed the nipple here, the spoke has no tension, and the end of the spoke comes just to the bottom of the nipple seat, which is as I described “minimum length”. With some tension, it would extend a bit further beyond the nipple seat.
If the spoke doesn’t protrude through the seat sufficiently, it could tear the nipple in half, which is something you’d notice or the wheel itself wouldn’t hold tension. Building a couple wheels like this and having the spokes almost come up too short led me to figure out that LB publishes the diameter of the nipple seat and adjust accordingly.
loading a brass tube seems very alarming to me, I’m not going to to the mech e problem set to see how likely it is that they would start snapping in half, suffice it to say that this is making me look at all 3 of my LB wheelsets with trepidation
This is how long my spoke is without tension. It grows by another mm when under tension. Zinn created this diagram to demonstrate what happens with aluminum nipples, brass are a fair bit stronger, which is all I use. Finally, the failure mode is some broken nipples, which is not catastrophic. This wheel has >5k miles on it and lots of hard abuse and had no issues. I cased a bunch of things really hard with this guy eventually sufficient to cause the rim to fail and the nipples were fine.
I built all of mine too, I’m saying that I’m now wondering if I accounted for nipple head length when I built them over the last seven or so years; it’s hard to remember
I see what you mean. I’d offer two things: the first is that if you haven’t seen nipple failures over the years, then you’re fine. The second being that if you used normal nipples and not double-square or squorx, you can peek at the bottom of the nipple and see. If it’s a standard flathead slot, the nipple should come to the bottom of the slot.
more like 2mm too short. 4mm off on the diameter = 2mm off on the radius. See Heath’s picture and diagram about “minimum length spokes” above. It’s not catastrophic as long as you’re not using aluminum nipples, but it’s definitely not best practice.
I have probably been there on a few different builds and hasn’t been much of a problem, perhaps coz brass and otherwise not keeping said wheels on bikes long enough.
I usually get too excited and base off spoke length off calculators and the posted ERDs.
yeah i get that. ya hit “buy” on the rims and nipples and hubs and then sit there vibrating for a week trying to resist the urge to hit “buy” on the spokes as well.
And the worst part is that I usually still go to the shop and cut the spokes myself. Just never have had to deal too much with the results. Maybe moving forward I will figure how to measure ERD myself properly.
I’m back with more dumb questions. What do I need to know about nipple length? I’d guess longer is stronger, more thread engagement? Are any of them so long as to have to worry about running out of threaded area on the spoke, itself?
I have always bought the shortest (standard length?) 12mm Sapim or DT Swiss nipples (or the “same length” 16mm doublesquare versions) because I’m not building on weird deep-section aero rims or whatever would require deeper nipples to have good access to the flats for truing.
And channeling my inner Jan about marginal gains: shorter nipples are lighter, and they’re out at the edge of the wheel where weight matters more (pay no attention to the fact that I build with brass nipples instead of alloy, no one ever said I had to be internally consistent). Never ran into any issues with this length of nipple.
But lemme level with you: I talk a good game but I am at best an amateur wheelbuilder, maybe there’s something that I don’t know about long nipples.
i think we started seeing nipple failures with a stock wheel with too short spokes within about 3-4 months on an e-bullitt with a wheel lock used daily by 4 different people
my clydesdale front wheel has minimum length spokes and that’s been totally fine for almost 6 years now and i do jump it a bit, occasionally with my kid on it (though 4” of air is probably generous with the kid on
anyone have thoughts on $150ish lightbicycle rims vs $250ish light bicycle rims?
having trouble telling the difference in value from the website. weight differences seem negligible.
