Having had the chance to have both the Dura-Ace C50 wheelset and the Ultegra C50 wheelset, it is now possible for me to do a comparison of these two wheelsets. From what I understand, there are many more similarities than differences between these wheelsets.
For areas that are not mentioned below, refer to the Dura-Ace C50 wheelset post for the details, as it means that it is the same for both Dura-Ace and Ultegra C50 wheelsets. For example, the carbon rims that are used are exactly the same, which is why they will have the same rim height and width.
White Dura-Ace logo on the wheelset is clearly visible, although the C50 logo is in grey which makes it less obvious.
Ultegra C50 wheelset looks very plain, as the logos are not obvious. Easy to mistake for a generic OEM carbon wheelset.
Grey logos are not very visible, and I think it is a deliberate decision to differentiate it from the Dura-Ace wheelset.
If you are looking for a wheelset where the logo is large and clearly visible, you should look for Zipp or other brands where the logo covers a large area on the rim. On the Dura-Ace rim, the logo is visible but small, while the Ultegra logo is practically invisible from a distance.
Dura-Ace hub has the logo and model number pad printed with glittery paint.
Ultegra hub has the model number laser etched (I think).
Dura-Ace hubs have black end caps and aggressive machining on the hub flanges to cut weight.
Ultegra hubs have silver end caps, and less machining on the hub flanges. This results in slightly more weight but lower production cost.
Dura-Ace hubs use straight pull spokes, with a plastic cover to prevent the spokes from sliding out of the slots.
Ultegra hubs seem to use the same construction, but with less weight-saving machining processes.
So far, only Dura-Ace rear hubs use the new Shimano road 12 speed splines on the aluminium freehub body. This reduces weight compared to the Ultegra version.
Ultegra rear hub uses the standard Shimano road 11 speed HG splines for the freehub body. As there are less splines, steel is used to prevent the steel sprockets from cutting into the splines.
Dura-Ace front wheel weighs 693 grams.
Ultegra front wheel weighs 710 grams, 17 grams more than Dura-Ace. I think most of the weight difference comes from the hub.
Dura-Ace rear hub weighs exactly 800 grams, with an aluminium freehub body.
Ultegra rear hub weighs 876 grams, which means a weight increase of 76 grams. Most of this additional weight comes from the steel freehub body.
Comparing the C50 rims, check out the different logo designs.
Dura-Ace C50 wheelset weight: 1493 grams
Ultegra C50 wheelset weight: 1586 grams
The Dura-Ace wheelset is 93 grams lighter than the Ultegra version, based on C50 rim profile. It is honestly not a very big amount, when compared to the whole bike and rider. If you don't mind an approximate 100 gram increase, you can save quite a bit by getting Ultegra C50 instead of Dura-Ace C50.
The aerodynamics of the Dura-Ace and Ultegra C50 wheelsets are probably the same, since they use the same rims, while the spokes look the same to me. There are many more similarities than differences based on the appearance.
However, there is a very big performance difference in the freehub mechanism. The Ultegra rear hub uses a traditional pawl and ratchet mechanism, with a large 20 degree engagement angle. This gives only 18 clicks of engagement per wheel rotation.
The Dura-Ace rear hub uses a star ratchet mechanism that is similar to the DT Swiss design. Due to this Direct Engagement mechanism, the engagement angle is small at only 7.2 degrees, giving 50 clicks per wheel rotation. This is only slightly larger than the Ascent Zenith Elite wheelset which has a 6 degree engagement angle.
This difference in engagement angle (7.2 degrees vs 20 degrees) is big and can be felt easily, especially when in low gears. On the other hand, if you are riding hard and pedaling nearly all the time, you would not notice this difference in engagement angle, as the mechanism is always engaged. Personally, I prefer a short engagement angle for a more snappy acceleration feel, with less free play in the pedal stroke.
In summary, other than the price, the main differences between Dura-Ace and Ultegra C50 wheelsets would be the weight (93 grams difference) and hub engagement angle (7.2 vs 20 degrees).
thanks, good info.
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