Right, controversial topic, a million answers!
What is the ERD of an EX823 rim? DT swiss used to say 538mm and everyone said they were wrong because their spokes were coming out to be too short.
I believe that this shortness was because DT's calculator shortens the spokes when you select longer nipples WHICH I BELIEVE TO BE A MISTAKE. I've read numerous threads (no pun intended) on the subject and compared my own 12mm and 16mm nipples, and my conclusion is that spoke length is irrespective of nipple length. Most nipples have the same amount of threading at the far end, and all that really changes is elongated flats for your wrench. Some nipples seem to have 1mm of extra threads maybe, but certainly not 4mm.
Oddly DT's calc persists in shortening spokes for longer nipples, and you'd think that they'd know.... nevertheless, I'm going to ignore them, and think that my fellow monkeys would be well advised to do the same.
DT have since lessened the ERD to 532mm. At first I thought this was because the newer EX823s have a deeper cross-section. They don't, it's the same (by my measurements).
Sicklines (our own jvnixon) claims the ERD of the EX823 is 528mm.
(http://www.sicklines.com/2008/02/04/2008-mavic-ex-823-and-mavic-ex-721/)
I fear he got this from measuring them himself, because if you measure the ID from one side to the other, that's close to what you get. Actually 526mm by my eyes. However, that's not how you measure an ERD. ERD is from the top of one nipple to the top of the opposite one. My nipples sit 4mm inboard of the rim, so ERD is actually 526 + (2 x 4) = 534mm.
FWIW the www.wheelpro.co.uk spoke calculator (the one Hope have on their site) agrees with me.
I'm about to order my spokes, and unless someone on here can convince me that some of the above is wrong, I'll be using 534 as my ERD and ignoring the what DT calc says about 16mm nipples. I'll be using several different spoke calcs cos I don't trust DT any more.
What is the ERD of an EX823 rim? DT swiss used to say 538mm and everyone said they were wrong because their spokes were coming out to be too short.
I believe that this shortness was because DT's calculator shortens the spokes when you select longer nipples WHICH I BELIEVE TO BE A MISTAKE. I've read numerous threads (no pun intended) on the subject and compared my own 12mm and 16mm nipples, and my conclusion is that spoke length is irrespective of nipple length. Most nipples have the same amount of threading at the far end, and all that really changes is elongated flats for your wrench. Some nipples seem to have 1mm of extra threads maybe, but certainly not 4mm.
Oddly DT's calc persists in shortening spokes for longer nipples, and you'd think that they'd know.... nevertheless, I'm going to ignore them, and think that my fellow monkeys would be well advised to do the same.
DT have since lessened the ERD to 532mm. At first I thought this was because the newer EX823s have a deeper cross-section. They don't, it's the same (by my measurements).
Sicklines (our own jvnixon) claims the ERD of the EX823 is 528mm.
(http://www.sicklines.com/2008/02/04/2008-mavic-ex-823-and-mavic-ex-721/)
I fear he got this from measuring them himself, because if you measure the ID from one side to the other, that's close to what you get. Actually 526mm by my eyes. However, that's not how you measure an ERD. ERD is from the top of one nipple to the top of the opposite one. My nipples sit 4mm inboard of the rim, so ERD is actually 526 + (2 x 4) = 534mm.
FWIW the www.wheelpro.co.uk spoke calculator (the one Hope have on their site) agrees with me.
I'm about to order my spokes, and unless someone on here can convince me that some of the above is wrong, I'll be using 534 as my ERD and ignoring the what DT calc says about 16mm nipples. I'll be using several different spoke calcs cos I don't trust DT any more.