E.R.D. of Mavic Open Sport?
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Hey, I can't find this info, either on Mavic's website or at my LBS that has the rim. Does anyone know?
The reason I'm asking is that I had a wheel with an MA40, that cracked at one of the eyelets, I think because it had been built with too high spoke tension. As such, the spokes probably don't have much fatigue and I'm looking for a rim with similar E.R.D. (effective rim diameter) to rebuild the wheel with the same spokes. MA40 has 613 E.R.D.; one option for rebuild is Sun M13II, which has an E.R.D. of 610mm. The Mavic MA3 had an E.R.D. of 611mm, so if the Open Sport is the same (the O.S. is hte replacement for the MA3) it should work fine. The Open Pro has a deeper cross-section of 605mm that probably wouldn't work with these spokes.
For the record, ERD is measured to the end of the spoke, usually flush with the head of the nipple.
The reason I'm asking is that I had a wheel with an MA40, that cracked at one of the eyelets, I think because it had been built with too high spoke tension. As such, the spokes probably don't have much fatigue and I'm looking for a rim with similar E.R.D. (effective rim diameter) to rebuild the wheel with the same spokes. MA40 has 613 E.R.D.; one option for rebuild is Sun M13II, which has an E.R.D. of 610mm. The Mavic MA3 had an E.R.D. of 611mm, so if the Open Sport is the same (the O.S. is hte replacement for the MA3) it should work fine. The Open Pro has a deeper cross-section of 605mm that probably wouldn't work with these spokes.
For the record, ERD is measured to the end of the spoke, usually flush with the head of the nipple.
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"c" is not a unit that measures tire width
"c" is not a unit that measures tire width
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From the road forum: The ERD of the Open Sport is 611mm, so they are lower profile than the MA3 (which is 607.5, according to spokecalc).
#3
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Hey Tim,
I asked about this a few weeks back:
https://www.bikeforums.net/bicycle-mechanics/163143-erd-mavic-open-sport.html
I also wrote to Sheldon Brown about it since he sold both the MA3 and the Open Sport, and he said he thought they were the same ERD or very close. A friend of mine measured the Open Sport at more like 607-608. So, bottom line, I'm not sure. I ended up not buying those rims.
I asked about this a few weeks back:
https://www.bikeforums.net/bicycle-mechanics/163143-erd-mavic-open-sport.html
I also wrote to Sheldon Brown about it since he sold both the MA3 and the Open Sport, and he said he thought they were the same ERD or very close. A friend of mine measured the Open Sport at more like 607-608. So, bottom line, I'm not sure. I ended up not buying those rims.
Last edited by simplify; 02-26-06 at 07:42 PM.
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Okay, interesting. I just took Thrifty1's word for it - he also posted the measurement of 611 in the thread that you started. (You had the same thread title as me, too; I should have searched.)
#5
ride, paint, ride
Originally Posted by timcupery
Okay, interesting. I just took Thrifty1's word for it - he also posted the measurement of 611 in the thread that you started. (You had the same thread title as me, too; I should have searched.)
Anyway, are you lacing 3-cross or 4-cross? If 4-cross, your spokes may be just fine with this much difference in the ERD between your MA-40 and the Open Sport. They may be fine anyway, with 3-cross, since there's room for the spoke to protrude a little bit without interfering with the rim strip or tube. Just so you can get enough tension before you run out of threads. But you know all that.
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How does the reported ERD for the Open Sports compair with Mavic's value for Open Pro's? I would think they would be the closest similar rim rather than the MA's.
BTW, here is a technique for actually measuring the ERD of any rim. Get two spokes, and thread a nipple onto each. Thread the spokes through two spoke holes 180° apart and overlap them in the center of the rim circle with enough tension to be sure the nipples are seated in their beds. Make a witness mark across both spokes at some point where they overlap. Remove them from the rim, match the marks you made and measure the distance between the two nipple seats. That's the ERD.
BTW, here is a technique for actually measuring the ERD of any rim. Get two spokes, and thread a nipple onto each. Thread the spokes through two spoke holes 180° apart and overlap them in the center of the rim circle with enough tension to be sure the nipples are seated in their beds. Make a witness mark across both spokes at some point where they overlap. Remove them from the rim, match the marks you made and measure the distance between the two nipple seats. That's the ERD.
#7
ride, paint, ride
Originally Posted by HillRider
How does the reported ERD for the Open Sports compair with Mavic's value for Open Pro's? I would think they would be the closest similar rim rather than the MA's.
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Yup, the OP is deeper profile. I just compared my old cracked MA40 to a stock (unbuilt) Open Sport at a local shop, and I'm pretty sure the Open Sport is around 607.5 E.R.D. - exactly what the MA3 was. So, it ain't 611, although it might work fine with spokes that are calculated for 611, I'm just going to stay on the safe side and go with the Sun M13II - double wall single-eyeletted rim like the Open Sport and MA3, but with non-machined sidewalls (they're just brushed).
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"c" is not a unit that measures tire width
"c" is not a unit that measures tire width
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Originally Posted by timcupery
Yup, the OP is deeper profile. I just compared my old cracked MA40 to a stock (unbuilt) Open Sport at a local shop, and I'm pretty sure the Open Sport is around 607.5 E.R.D. - exactly what the MA3 was. So, it ain't 611, although it might work fine with spokes that are calculated for 611, I'm just going to stay on the safe side and go with the Sun M13II - double wall single-eyeletted rim like the Open Sport and MA3, but with non-machined sidewalls (they're just brushed).
#10
ride, paint, ride
I think those Suns are really nice, classic-looking rims. Personally, I hate the fact that Mavic has added those wear-indicator lines to the Open Sports. I know they'll be less noticeable eventually, but in the meantime, I hate that a groove has been carved into the sidewall, and they're just plain fugly.
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Originally Posted by lawkd
Personally, I hate the fact that Mavic has added those wear-indicator lines to the Open Sports. I know they'll be less noticeable eventually, but in the meantime, I hate that a groove has been carved into the sidewall, and they're just plain fugly.
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Originally Posted by lawkd
I think those Suns are really nice, classic-looking rims. Personally, I hate the fact that Mavic has added those wear-indicator lines to the Open Sports. I know they'll be less noticeable eventually, but in the meantime, I hate that a groove has been carved into the sidewall, and they're just plain fugly.
Tom O'Hara
#13
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I had to lace up a set of Open Sport rims and since they weren't listed in Bike-a -Log yet, I called tech support at Mavic and was told the E.R.D. was 606. I used this when I figured out the spoke lengths and it all worked out fine.
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I don't particularly mind the wear indicators (though I've not had a bike with one) - I think they're a useful thing, although I dislike the tech-y rim look. I do think that the Sun M13II is a really nice-looking rim though, and the Mavic OS is not. That said, Mavic has a rep for better quality control - their rims are more consistent in weight, etc. Although the Sun M13II has a better rep in terms of not cracking at the eyelet (compared to the Mavic MA3; the Open Sport hasn't been out long enough to see how it compares to the MA3 on the cracked-eyelet count).
Here's a thread I started in the road forum, asking for feedback on the M13II. Not bad, is the general feeling.
Here's a thread I started in the road forum, asking for feedback on the M13II. Not bad, is the general feeling.
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"c" is not a unit that measures tire width
"c" is not a unit that measures tire width
Last edited by TallRider; 03-01-06 at 08:14 AM.