New wheels for the Birdy AXS 12 speed folding bike! I will be upfront and say that I got these carbon wheels mainly for the looks, and partly for the lower weight. Other than that, I don't really care about the aerodynamics or performance of this wheelset.
Let's jump right into it and let the pictures tell the story!
These carbon wheels are made by Suncord, which is known for making aftermarket components for the Brompton.
These carbon wheels have a unique 4 spoke design! I initially wanted the 5 spoke design but was told it is no longer available and they have moved to 4 spokes for better comfort and lower weight.
Suncord logo splashed across the rim, in a style that reminds me of SRAM.
20" 406 wheel size, same as the Ascent Cirrus Elite carbon wheelset that is currently on the Birdy.
I chose the carbon weave design with a gloss finish, as it would be easier to clean compared to a matte carbon finish.
Due to the 4 arm design, there are no spoke holes on the rim at all. What you see here is the valve hole.
This also means that there is no need for rim tape since there are no spoke holes.
Internal rim width is 18.5 mm, which is slightly narrow but not too narrow like 16 mm.
External rim width is a healthy 26.5 mm.
Rim height is 38 mm, which is a nice balance between visuals and susceptibility to side winds.
The 4 arms blend into a large section in the middle where the hub is. This hub has Centerlock rotor mounting.
There is no traditional hub and hub shell in the middle. Rather, the carbon forms a cavity for the internals of the hub to be inserted and bonded.
Other side of the front wheel showing the "hub".
Rear wheel comes with the XDR driver, but can be swapped for other freehub bodies as well.
Non-drive side of the rear wheel showing the Centerlock splines. Interface between the hub and the carbon parts is interesting.
I believe the carbon rims/spokes are the same for the front and rear wheels, just that the hub components are different.
A glossy top coat makes these carbon wheels look shiny!
Front wheel weighs just 456 grams
Rear wheel is just 593 grams!
Ascent Cirrus Elite Carbon Wheelset (20" 406)
Front Wheel: 560 grams
Rear Wheel: 657 grams
Total: 1217 grams
Suncord 4 Spoke Carbon Wheelset (20" 406)
Front Wheel: 456 grams (104 grams less)
Rear Wheel: 593 grams (64 grams less)
Total: 1049 grams
This Suncord 4 spoke carbon wheelset is more than 160 grams lighter than the Ascent Cirrus Elite, which itself is already pretty lightweight! The only other 20" 406 wheelset that I know of that is lighter, is the Dahon Kinetix Pro wheelset that weighs just 998 grams. Even so, that wheelset has a narrow and shallow rim, as well as being rim brake compatible only, which makes it lighter than disc brake compatible wheels.
At the same time, I also ordered the Shimano HG spline freehub body, just in case I want to put on other cassettes.
Shimano HG spline freehub body, made of titanium to ensure durability while saving weight over a steel version.
Freehub body weighs 91 grams, which is heavier than aluminium ones but lighter than steel.
It uses a hybrid metal spring + magnets to activate the pawls. I first saw this kind of magnetic pawls on the Ascent Zenith Elite wheelset.
For this kind of hybrid pawl and ratchet system, the metal spring provides minimal spring force, to minimize the rolling resistance and energy lost during freewheeling. However, just reducing the spring force from a traditional pawl spring system would cause the drivetrain to slip and skip when you pedal hard, as the weak spring cannot prevent the pawls from slipping out of the ratchet during high torque conditions.
Therefore, the magnets on the pawls are designed to keep the pawls fully engaged in the ratchet, without requiring a high spring force to keep them there. Ideally, this system would maintain the engagement required during high torque conditions, while minimizing the energy lost during freewheeling. Hopefully it helps to reduce the freewheeling sound as well!
In the next few posts I will show the installation of the Suncord 4 spoke carbon wheelset onto the Birdy AXS.
