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anyone bored want to check my spoke math???

653 Views 9 Replies 6 Participants Last post by  Mike T.
here is my rear wheel build...

hope pro 2 ss hub
pitch left 56 . pitch right 54
flange left 31.50 flange right 20.50

DT Swiss x470 29er
ERD 606

32H with 3 intersections =

left = 293.8 right 293.10

now my question is do i round them both down to 293? or both up to 294?

or do i buy 16 spokes at 294 and 16 spokes at 293?????

i ve seen alot of theories on this .... any suggestions would be appreciated....

im still a wheelirgin---- thanks
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I'd rather be a millimeter too short than a millimeter over. Been there, done that, ran out of threads and couldn't tension sufficiently.

If you have the choice of both lengths, do it. All 294 wouldn't kill you if your numbers are accurate, but I'd just as soon round the 293.1 down to 292 if I had just even length spokes to choose from.
thanks but...

i lost ya speed....

i thought i understood until the last sentence.....

when you said
"...but I'd just as soon round the 293.1 down to 292 if I had just even length spokes to choose from..."

did you mean 293? instead of 292?

because the other side is 293.8 and rounding that down to 293 and the other side to 293 makes sense to me.... the 292 is just mind fu**in me right now....
Many spokes you can buy are available only in even lengths.

even - as in the number value


even - as in =

ok ok,,,, i did find some odd numbers though.... so 293 for both is the way to go....
nicolicious said: 293 for both is the way to go...
Well, like I was saying, if you can get both 293 and 294, I'd split my order.

If your ERD measurement is accurate, either length will be fine. But for every millimeter your ERD might be off, your required spoke length changes by approximately 1/2 mm. And it's not uncommon for measured ERDs to have a millimeter or two of variance from the published ERD.

If you're using brass nipples and your spokes come up a tiny bit short, that's OK, they'll carry the load. But if you're using aluminum nipples, you want the spoke to thread into the nipple head as much as possible (to the bottom of the slot in the nipple head) so that the head is supporting as much of the load as possible.

That's all a bit more than your initial question asked. Let's assume your numbers are accurate. If both spoke lengths are available, best to order 16 of each length.
I agree with Nate...

if you can get em, split your order and get both 293s and 294s. It's always better to get the spokes as close as possible if you can. Going 293 for both would likely be fine assuming that all measurements are correct. But as noted, a mm one way or the other can make a difference. If you are confident that the ERD you are using is correct then the 293s will be fine. If there is any doubt at all, then split em.

Good Dirt
You say it's a ss (trials) hub, but your offsets are for the 9-speed version. if you do indeed have a trials hub, it is dishless and both offsets are 32mm.
Actaully, the red alert is not that big a deal. In both cases I'd go with 293s all around, though 294s will work fine and you'll have no problems. My calculator accounts for spoke strain (stretching under tension). Calculated length is for the built wheel (strained condition), but you purchase unstrained spokes, which means that the spokes you buy are a tad shorter than they will be in the wheel (up to almost 1mm, depending on the spoke and the tension). With the +/- 1mm rule, it usually doesn't make too much of a difference, but it can affect a rounding decision and I'm an engineer who likes to gnat's ass things. the most important thing is that your ERD number is good. I have more confidence in DT than most other manufacturers, but I'd still measure if you have a chance.
thats good to know....

now i just dont know.... i used the dtswiss calculator and they didnt have a hope pro 2 rear ss option,,,,,

but the tire is theirs so it should be an erd of 606....... shipment is coming monday so i guess i ll have to freaking wait....

anyone one out there running a
dt swiss x470 know there erd or want to do a little measuring for me.????

meltingfeather said:
**RED ALERT** I'm an engineer who likes to gnat's ass things.
I don't hit many nails square on the head but I did the day I sent ya that Avatar pic :D
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