The Anemoi Basebar
Designing and developing the Anemoi basebar has been an extensive undertaking for the WattShop team over the past 18 months. We knew from the very beginning with our Electron Pro specific Pentaxia basebar that we have a great product but as it was a frame and event specific component there was plenty of further research, development and optimisation to be done. To this end, we have focused on producing best-in-class aerodynamics alongside high quality UK manufacturing and safety testing that far exceeds the ISO standard for bicycle steering components.
When considering aerodynamics of the cockpit, the primary concern is enabling the athlete to achieve their optimal position through a broad adjustment window. We have discussed how we’ve achieved this in our Adjustment & Customisation blog. Secondary to this is the drag induced by the basebar and the impact its wake has on the rider’s drag downstream, which is still very significant.
We focused our development on reducing the aerodynamic drag of the basebar where its wake wasn’t beneficial to reducing total system drag, and to then optimise our design to interact optimally with the rider.
To achieve the first goal we narrowed our basebar down to 32cm centre-to-centre. This removes a significant amount of drag that is shed outside of the rider, especially at yaw, bringing it inline with the rider’s legs. It also narrows the rider’s profile when they are on the basebar, reducing their drag further in this scenario. We then spent considerable effort to optimise the basebar airfoil profile at low pitch angles (airflow parallel to the ground) but to be insensitive to higher pitch angles caused by rider’s forearms when in low stack height configurations.
The smaller details were also considered, using CFD to look at areas of possible flow separation and manipulating blends and surfaces to reduce and remove these. Our stem cap is a good example of this, aiming to create a clean transition from the stem to your frame’s top tube, whether your frame has a standard style steerer or integrated system.
Our wind tunnel test results compare the Anemoi basebar to two high-performing basebars (3T Aduro & Shimano Pro Missile Evo) along with our partner team’s, Uno-X Pro Cycling, Dare TT bike basebar. This test was performed at Silverstone Sports Engineering Hub, with SSEH supplying an independent test rider. The rider’s position was matched across each basebar. Each setup was tested at 40km/h, 50km/h and 60km/h with yaw angle increments of 3 degrees between 0 and 15 degrees. Instead of packaging up our results with a yaw weighting scheme that will never truly represent the real world as this will vary course to course, rider to rider and conditions to conditions, we have presented all of our results for all speeds and yaw angles in CdA, CdA delta to each basebar, wattage delta to each basebar and seconds saved per km. We believe that in the modern world of cycling it is better to present all data and allow the user to interpret it to suit their own event demands as an Ironman age group triathlete will have significantly different speeds and yaw angles than a world class track pursuiter. However, we are also aware it is helpful to give some scenarios to compare performance between. See below for a range of examples and how much you could improve your performance.
COMPOSITE LAYUP AND SAFETY TESTING
Using our experience in high performance composite applications and working alongside our UK based factory, we have developed the construction of the Anemoi basebar wings to provide the ultimate combination of structural integrity, low weight and fatigue resistance. The mouldable nature of carbon fibre allows us to accurately form each basebar to exacting tolerances with repeatability. We use quality, composite, carbon fibre fabric, CNC cut into panels and laid up to our specification, meaning each layup is exactly repeatable, in terms of number of plies, ply weave orientation, ply weight and overall thickness. Our pre-preg supplier are certified to EN9100: 2018 Aerospace Standard, and our composites manufacturer to ISO 9001 and 14001, thus ensuring quality component delivery.
Curing in a highly polished aluminium tooling provides the uniform, defect free finish seen on each pair of Anemoi basebar wings. The pristine surface finish requires no lacquer or treatments. We have coupled the benefits of carbon fibre, with aluminium 6082-T6 bonded hardpoints, so the major load paths are properly supported, providing the rider with reassurance that the Anemoi basebar is not only fast, but safe too.
We have added multiple failsafes throughout our design. Each adjustable and modular aspect of the design has redundancy built in. Our stem axle is secured in three different ways, as are each of the wings, meaning even if a bolt should come loose your cockpit will stay securely in place.
The Anemoi basebar has been independently tested to exceed the ISO standard ISO 4210-5:2014, the safety standard for bicycle steering components. A breakdown of each of the tests the Anemoi basebar has passed is below:
PASSED - Fatigue Test. Out-of-phase and in-phase loading. Out-of-phase; 100,000 cycles of 325N (33.1kg per side) at the basebar grips. In-phase; 100,000 cycles of 400N (40.7kg per side) at the basebar grips. Tested in accordance to ISO 4210-5:2014.
Out-of-phase loading is where the load is applied down on one grip and up on the other grip (opposite loading forces). In-phase loading is where the load is applied in the same direction to both grips.
PASSED - Static Test (maximum load single sided). Maximum 1,100N (112kg applied to one side of the basebar) at the basebar grip. Tested in accordance to ISO 4210-5:2014.
- PASSED - Static Test (maximum and overload). Maximum 1,200N (122kg applied across both sides of the basebar) and overload of 1,450N (147kg applied across both sides of the basebar) at the basebar grips. Tested in accordance to ISO 4210-5:2014
A full test report is available HERE.