Review: Magene Exar RB45 Pro Asymmetric Road Bike Wheels
Introduction
Magene are a fairly new entrant into the road bike wheel marketplace but they are well known for their power meter and turbo trainer offerings. Magene also have a large OEM presence. Exar is their wheel specific sub brand.
The wheels on test are RB45 Pro rim brake wheels with a Shimano freehub. They retail at $970 (this will vary slightly depending on where you live)
Specification
- 45mm Rim Depth
- 27mm Front wheel width
- 26mm Rear wheel width (Asymmetric)
- ~19mm internal with
- 1330g in Weight (1360g measured with rim tape)
- Pillar Spokes
- Comes with skewers, rim tape etc
Asymmetric Section profiles
The stand out feature from the spec sheet is without doubt the use of an asymmetric rear section profile. The offset nature of the spoke attachment allows an increase in the lateral angle of the spoke and thus makes the wheel stiffer. Many other companies attempt a similar strategy by widening the hub flanges to increase the lateral spoke angle.
Aerodynamically, the rear rim is quite blunt and as a consequence in isolation would behave like a bluff body or a heavily sectioned Kamm Tail. For practical purposes, air will have had most of it’s residual energy taken out by the time it gets to the rear wheel so the aerodynamic effect is small.
The front wheel mimics a tried and tested teardrop design albeit it is working within the confines of a 45mm rim depth. The section is symmetrical with radial spoke lacing.
On the Road
The wheelset has a measured low moment of inertia so it accelerates quite quickly. Braking performance is good and it is noticeably very good in the wet where the cuts in the brake track do a good job at dispersing water. The mechanical wind up in the hubs and spokes is low so there is not much in the way of flex when riding the bike out of the saddle and rocking from side to side.
The rim depth is quite shallow so it is not greatly effected by cross winds.
Hubs
The hubs are a strong point of the Magene wheels, the machining tolerances are excellent. The rolling friction of the assembly is low.
The rear bearing setup consists of two deep groove radial ball bearings in the freehub and an additional two deep groove ball bearings supporting the rear wheel. The ratchet assembly is free moving although it is not quiet when free wheeling.
Residual Balance
The limit value for out of balance is around 610g.mm. These wheels are comfortably inside that and as a result in an unbalanced state, the self excitation noise is low. It is also a broad indicator of a well made rim.
Ultransonic checks of the rim showed very even thickness throughout.
Crosswind Stability
The wheel is fairly shallow and as a result, it is largely immune to crosswind issues. It would require an extremely blustery day to cause any issues for almost all riders.
Aerodynamic Performance
The ultimate aerodynamic performance is affected by the depth and to an extent the width, the shorter profile results in a larger undefined area (ie the spoke swept area) this results in a larger area for turbulence to develop. A wider wheel will also require a longer chord length for recovery of the flow.
Photo Gallery
Overall Conclusion
The outstanding feature of these wheels is the execution of the hub. The tolerances are very fine and have resulted in free spinning bearings all around. The net result is a wheelset that has very low induced vibration. The bearings do require a considerable break-in period, the wheels will only reach minimal friction after about 300-400km.
Aerodynamic performance is limited by the depth. Magene also offer a 58mm depth wheel which is slightly heavier but will have much better aerodynamic properties owing to the more favourable cord to thickness ratio. Ultimately the drag was as predicted and hence average for a wheelset of this depth and width. At this price point, it does represent a decent set of wheels.
