I’ve done this before with unusual things like straight pull hubs or old internal nipple rims. . It’s not perfect. But it will get you well within the ballpark.
1 Like
Do you have a calipers? Taking measurements with the spokes in the way isn’t ideal but should be doable
I do have calipers and knowledge of how to measure the hub. I could give it a go but it does seem a bit fucky…
How long is it going to take you to get spokes? I know it sucks to be down a bike while rebuilding a wheel, but if it makes you more comfortable measuring the bare hub then I think you should cut it out and order spokes all in one movement.
Difference divided by two should be fine imo. You can get a feel for how accurate it is by mocking something up in a spoke length calculator and seeing what happens when you add 12mm erd. Because the spokes are likely not radial the erd difference/2 may be a little short. In my case though it rounded to that.
@Face:
probably a bit over a week, no one round here really stocks that many (32 + spare) spokes in 276mm. So I’d have to order online.
@Andrew_Andeson:
that’s a good idea, I’ll probably do that!
Having made the mistake of ordering the wrong spokes no fewer than 3 separate times in my life, I believe the only true option is to cut the hub out and measure it. Having to wait an extra week and be out the $$ for the wrong spokes is worse than waiting only one week for the 100% correct spokes. ATMO YMMV BBQ.
3 Likes
Also, trusting published ERD is always a gamble.
3 Likes
@EndpointBraden: I know it is, but I put a little faith in DT Swiss knowing their stuff.
Anyhow, I have now measured the hub with the spokes still in it and I’m pretty heckin bamboozled I tell you:
142 OLD in half is 71.
Left flange is 38mm from hub end (64mm PCD)
Right flange is 56mm from hub end (also 64mm PCD)
So 71–38=33 & 71–56=15, threw it all into Dt Swiss calculator and it gives me 271/270 L/R spokes. Which is the fucking same length that the spokes in the wheel right now has WITH A 550ERD RIM??? D fuq…?
So I threw the exact same numbers into Sapim’s calculator and that gave me the suspected correct 276/275 spoke length. Dt swiss confine calculator must be on some of that bad dope…
following @Orc ‘s trick for lacing a 32h rim to a 48h hub. On the second side, the angles the spikes make at the hub look wrong — how did I mess up? Or is this just the nature of the kludge?
That looks fine to me?
OK! None of my other wheels have had the spokes overlap the heads of other spokes so I wasn’t sure
Has to do with hub flange diameter. The larger the hub flange, the more overlap you get at the flange when compared to smaller hub flanges.
That looks like a pain in the ass to replace a spoke if it breaks, if the spoke is actually covering a portion of the next spoke head.
But the simple solution would be to just back out the tension on the obstructing spoke, yes? It would need to be retrued anyway, so might as well be hung for a sheep as a lamb
I know that’s the big ass pain with building 36h bmx wheels
Why add more steps to do the same work?
Maybe I look too much at the time spent side of things…
1 Like
Get shorter spokes to have one less cross.
Shifted one of the holes for the trailing spikes to even out the lengths and it turned out OK in the end for a first wheel build with 100% parts bin parts. Still need to replace the bearings though
2 Likes
have you met orc?
i haven’t. but one day i hope to.
1 Like
I’d listen to their podcast for sure.
1 Like