spoke length

[FDS2223]

How long are spokes for a front mod wheel supposed to be? and since its a disc hub are there supposed to be two different lengths?

[beastoftheeast]

depends on your hub and rim. go to tarty bikes and find out the erd (effective rim diameter i think) of your rim. then you got to measure some distance of the spoke holes. then calculate your spoke length. google that shit.

[va_tick]

http://www.sheldonbrown.com/rinard/spocalc.htm from a recent thread

[FDS2223]

Does anyone know what the ERD of the old echo front (20") rim is? They were out about a year ago and are flat across the rim face (inside of rim facing hub)

[HipHopapotomus]

http://www.sheldonbrown.com/rinard/spocalc.htm from a recent thread

this is an awesome link. i've built many wheels with this.

p.s. you need the ERD of the rim, plus you need the flange diameter of the hub and the center-to-left flange and center-to-right flange measurements (which are usually the same thing on a front hub) you can measure these pretty easily with a caliper if you can't find the measurements

[FDS2223]

I just tried to find the ERD with a measuring tape and by my measurments (:noes:) it is 396.875 mm. I don't have very accurate tools so I might just say fuck it and buy a new (and current) rim.

[tomacropod]

a new rim won't be any easier to measure...

- Joel

[FDS2223]

I don't want to measure it, I just want a rim that already has the ERD available to me. The rim I have now is no longer sold by any dealers so no one can tell me what it's ERD is.

[HipHopapotomus]

well ultimately you have a little room, maybe not as much on a mod wheel, but on 26 and 700 wheels, the spoke length has about a 2mm room for rounding, it doesn't have to be perfect, especially because your calculated spoke length is often not a round number.

as for measuring your ERD... i've done it with a tape measure before with no problems, just be sure to add a few mm (usually 4-ish) to the diameter of the inside of the rim, because you have to take into account the thickness of the rim wall, since the ERD is the distance between where the nipples sit inside the rim.

[FDS2223]

As much as I appreciate the help, I don't trust myself to get the measurements accurate enough and I'd fucking tear my hair out if I got the wrong size spokes again. Its already been over two weeks since Ive ridden and I would flip out if I had to wait any longer than what I already have to. I will probably buy some of those measuring calipers you mentioned and then figure out how to make this rim work while I have something to ride on and am not so stressed out.

[beastoftheeast]

just take it to a bike shop and have them figure it out and if they fail dont pay them.

[FDS2223]

I PMed thetart to see if he still had the ERD of the old rim and he did; 395mm. So a big thanks to him. I guess I was pretty close with my measurements, only off by about 2mm. I'm curious if that would have made a significant difference?

[va_tick]

well ultimately you have a little room, maybe not as much on a mod wheel, but on 26 and 700 wheels, the spoke length has about a 2mm room for rounding, it doesn't have to be perfect, especially because your calculated spoke length is often not a round number.

as for measuring your ERD... i've done it with a tape measure before with no problems, just be sure to add a few mm (usually 4-ish) to the diameter of the inside of the rim, because you have to take into account the thickness of the rim wall, since the ERD is the distance between where the nipples sit inside the rim.