# Mavic Open Sport Rims



## Mr. Peabody (Dec 8, 2005)

I'm thinking of building up a new all-around road/touring wheelset, and I am considering the Mavic Open Sport rim. 

Seems fine for half the price of the Open Pros. 

Anyone have experience (good or bad) riding on these rims?

Thanks.


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## cmg (Oct 27, 2004)

i thought these were a renaming of the Mavic MA3. check out velocity rims the have similar priced 490g rims too. i have a set of MA3, rock solid, about 3k mileage never trued them.


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## Mark McM (Jun 18, 2005)

cmg said:


> i thought these were a renaming of the Mavic MA3.


Nope, the Open Sport is a completely new rim. Unlike the MA3, the Open Sport is narrower, has a triple-chamber cross-section (MA3 was single chamber), and has sidewall wear indicators.

The MA3 was widely considered a dog; it was not reliable and frequently cracked at the eyelets. Mavic, probably aware of its shortcomings, even spec.'ed lower spoke tension and rider weight limits than the lighter Open Pro rim.


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## cmg (Oct 27, 2004)

*they're different?*









and







both 490g. don't really look that different. the groove on the brake face is the wear indicator.


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## Mr. Peabody (Dec 8, 2005)

I recall seeing an Open Pro rim right beside a Mavic MA3 in my local shop (no, they don't have the Open Sport rim there). 

The mechanic was explaining that on the Open Pro, the threads in the eyelets continued through the center channel to the other side, so that when the spoke was threaded in, it would have more surface contact, or threads, to bite into. I'm not quite sure what he was referring to, and hopefully someone can shed some light on this. I suppose my next move is to phone the folks at Mavic, since their website contains only the most basic information. 

Any input would be appreciated. Thanks.


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## Mark McM (Jun 18, 2005)

cmg said:


> both 490g. don't really look that different. the groove on the brake face is the wear indicator.


If you look closer, you'll see that that the internal cavities are shaped differently. This can be seen more clearly here: Open Sport cross section. As you can see, the two side cavities had to be re-shaped to accomodate the wear grooves. This requires completely new tooling (extrusion die). Also, as can be seen in the two photos you provided, when they re-designed the extrusion, they also made the spoke bed thicker (probably because of the high number of spoke hole cracks with the MA3). Although it may fill the same market niche, it is a completely new product.


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## Mark McM (Jun 18, 2005)

*Eyelets and sockets*



Mr. Peabody said:


> The mechanic was explaining that on the Open Pro, the threads in the eyelets continued through the center channel to the other side, so that when the spoke was threaded in, it would have more surface contact, or threads, to bite into. I'm not quite sure what he was referring to, and hopefully someone can shed some light on this.


Well, there's no threading involved in the rim, but the Open Pro is socketted, whereas the Open Sport is simply eyeletted.

On the Open Sport, there is a eyelet (a metal grommet) crimped into the spoke hole. This eyelet supports the nipple, and helps distribute the spoke load more evenly onto the bottom rim wall.

On the Open Pro, in addition to the eyelet, there is a socket, which is a thimble shaped insert that has a lip at the top of the socket that rests on the inner rim wall, as well as the bottom of the socket resting on the bottom rim wall. The socket helps distribute the spoke load to both rim walls, so that the each rim wall experiences only about half the spoke tension. Sockets are sometimes referred to as double eyelets.

If designed and built correctly, a socketed rim can be more durable, and less prone to cracking around the spoke hole. Due to changes in rim design and construction technology, the need for sockets has been diminished in recent years, but frequently non-socketted rims have to be a little heavier for the same durability.


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## Mr. Peabody (Dec 8, 2005)

Good information, thanks to all who replied. 

It seems for my purposes the Open Sport rims will be fine. I'm not interested in the lightest weight rim available, but I do appreciate Mavic quality (use their rims on my mountain bikes), so I'll most likely try the Open Sports. I've noticed Kona specs them on the Jake the Snake, so if they're strong enough for cyclocross, I'm sure they'll suit a road/light-touring bike. 

I was considering an LX front hub (or possibly 105), and a 105 rear. I'll be sure to post a report once I have them built.


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