How do the RX compare to the R2?
Lighter and pricier, probably. But bearings and otherwise similar?
I originally ordered the RX hubs (~205 g) because the weight is impressive, but once I started running the spoke and rim calculations, the build stopped making sense for my use case.
The rims i have chose are 65 mm deep, 25 mm internal, 32.4 mm external, 425 g each, with a 100–110 kg load rating. I’m 78 kg, ~85 kg with bike and kit, so I’m well within the limit but not by a huge margin. On a deep 65 mm rim, lateral stiffness and spoke strength matter more than chasing the last 70–80 g in the hub.
The spoke data is what really pushed me away from the RX:
2.3 mm spokes
• Tensile Force In Destructive Testing: 280–300 kgf
• Outgoing Inspection: 180–200 kgf
• Lateral rigidity failure: 80 kgf
3.1 mm spokes
• Tensile Force In Destructive Testing: 350 kgf
• Outgoing Inspection: 280 kgf
• Lateral rigidity failure: 80 kgf
3.95 mm / 5.1 mm spokes
• Tensile Force In Destructive Testing: 500 kgf
Outgoing Inspection: 320 kgf
• Lateral rigidity failure: 115 kgf
The RX hub only accepts steel or carbon spokes up to 2.3 mm. That caps both the tensile margin and the lateral rigidity before failure at 80 kgf. For a 65 mm rim under an 80+ kg system, that was simply not enough margin.
There is a carbon spoke that fits the RX, but it’s almost 5 g per spoke—so to make the RX work, I’d have to use heavier spokes that completely erase the hub’s weight advantage.
By contrast, I already have an R2 wheelset on 55 mm rims using 3.2 mm spokes, and that setup works extremely well. The R2 geometry clearly supports larger‑section spokes without issues, and the stiffness difference is obvious on the road. That real‑world experience made the decision even clearer.
So I switched to the THR R2 hub (285 g pair):
• 7075‑T651 shell, TC4 Ti axle
• 2:1 rear lacing with 3‑cross on the drive side
• Asymmetric flange layout for better tension balance
• Accepts 3.95 mm spokes without restriction
With the 3.95 mm spokes, I get:
• A huge tensile margin (500 kgf vs 280–300 kgf)
• Higher safe build tension
• A major jump in lateral rigidity failure (115 kgf vs 80 kgf)
• Better stability on a deep 65 mm rim
• A safer structural margin given my system weight
Once you compare the full system:
RX + thin spokes → low stiffness, low margin
RX + heavy carbon spokes → kills the weight advantage
R2 + 3.95 mm spokes → similar total weight, far better stiffness and durability
It becomes obvious that chasing the lightest hub is the wrong optimisation. Spokes and geometry dominate how the wheel actually performs.
That’s why I cancelled the RX (also nearly $1000 USD) and went with the R2 + 3.95 mm spokes.
I still have time and I am looking at other spoke options, but the direction is clear: prioritise spoke section, stiffness, and safety margin over saving a handful of grams in the hub.
