Check my spoke length calculations, please

Tarckives Bikes
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I’m building 2 wheelsets and wanted someone to check my calculations before I placed the order.
Front Hub: Phil Wood LF track
Front Rim: H+Son Formation Face
Rear Hub: Phil Wood LF track single side fixed
Rear Rim: H+Son Formation Face

The listed ERD of H+SON Formation Face rims is 557 so I added 3mm for nipples to the ERD

Should I go with 272 or 273 length spokes for the front?

Front Hub: Superbe HF track
Front Rim: Open Pro
Rear Hub: Superbe HF track single side fixed
Rear Rim: Open Pro

The listed ERD for Open Pro is 602 so once again I added 3mm for nipples

I was thinking 292 for the rear

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257mm for the front and lace it radial, otherwise I came up with the same number for 3x. Otherwise, 272. Will 12mm nipples work for that or do you need longer? Also, I came up with the same number for the rear. 292 should work fine.

3

I really want to build some wheels but all this fucking math is getting in my goddamn way!!!

4

haha when i built my front wheel i made the lbs do the math

5

Pick the parts you want to use, post up the details and let someone else tell you what spoke length to buy.

6

It’s not too hard Rusty. Once you run a spoke calc it a few times you get a feel for how it all works. All the actual math is handled by the program, you’re just entering in data. The tricky part is just in getting accurate data.

7

It is tempting to go radial on the H+SON to Phil, sadly it can’t be done with the Superbe/OP combo as the Superbe has been laced 3x in the past.

Also, I am right in adding 3mm to the ERD for the nipples, right?

8

Usually. I calculated this wrong on some CXP33s I built once and had spokes that were a bit too long. Wasn’t a big deal, had a mm or two sticking out the top of the nipple.

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Zombie’s wheelset made me decide to go radial front, thanks little buddy!

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Looking good!

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Is this common practice? I have never done this or heard of doing this. I’ve used spokecalc to build probably 10 wheels and I’ve never had short spokes.

I used to do this until I got a set of spokes barely long enough to radially lace a rear wheel.

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don’t need to add +3 to H Plus Son as ERD includes it.

13

Right. I though ERD always meant the diameter of the circle defined by the spoke beds. (or it should be, anyway)

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Good to know, i’ll modify it accordingly

15

i don’t add anything for nipples.
spokecalc always seems to give me spokes a mm or two too long in the calculations so i’d round down.

16

spokes will stretch over their lifetime too so always round down.

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Is this common practice? I have never done this or heard of doing this. I’ve used spokecalc to build probably 10 wheels and I’ve never had short spokes.[/quote]

Figuring out proper ERD for Mavic rims can be an issue for this reason. Specifically, there are two numbers floating around for Open Pro, with and without the added few mm.

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[quote=cookietruck]i don’t add anything for nipples.
spokecalc always seems to give me spokes a mm or two too long in the calculations so i’d round down.[/quote]

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[quote=sneaky viking][quote=cookietruck]i don’t add anything for nipples.
spokecalc ALWAYS seems to give me spokes a mm or two too long in the calculations so i’d round down.[/quote][/quote]

Also, the spocalc erd for Sun CR18s includes the extra 3mm so it might for other rims too.

I recommend buying them spokes from a good LBS who will do their own calculations. Take all your figures in and get them to check. That way, if they end up being wrong the LBS will let you swap them over - it’s on their head. A nice bit of insurance I think. Worth the extra $5 or whatever rather than buying online

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