AlterLock CycleGuardService

#3 Report on the development of AlterLock

Please check the following articles for previous editions.

How will the device mount on the bike?

What do you think?

The design follows the bottle, as it is recommended to be mounted on the down tube.
This is the opposite of the current version, which is designed to go from the seat tube to the down tube and along the bottle cage, rather than along the frame.

There are several reasons for this.

  • Improved antenna for a more efficient signal
  • Bike frames have original shapes each by each. So, it is easy to fit for the bottle cages.
  • The device is more discreet when mounted with a bottle cage
  • When there is only one bottle cage on the bike, the down tube is the most common mounting point
  • The down tube is generally thicker and therefore the whole device is more easily hidden behind the down tube (less impact on the frontal surface area)
  • If the device covers the frame, it will interfere with the design of the frame.

As aero frames have become more and more common in recent years, we have heard many users say that they are not comfortable installing a device that is wider than the aero frame (with a narrow seat tube).
We have also seen some users mount the device on the down tube or opposite side, because they were concerned about the aerodynamic effect. The changes to the mounting position and shape of the second version are the result of this feedback and actual use.

Aerodynamic simulation

The changes to the mounting position and shape of the device have improved the impact on aerodynamic performance.
So how much has it improved?
This time, we have done the analysis through fluid dynamics. That is the thing used in the design of frames and wheels for high-end models as well as aircraft and cars. The analysis was carried out by Altair Engineering, a global provider of CAE solutions for all sectors of the industry, using eight NVIDIA Tesla V100 SXM2 16GB GPUs.

Results (impact of AlterLock when riding at 40 km/h)

  • Cd value: +0.00062
  • W conversion: +0.02442W

From this, the difference was calculated at a time difference of less than 0.002 seconds per hour, which means that even if we were fighting for 1/100 of a second, the generated air resistance would be close to zero. The difference of this data is slightly higher than usual because we chose an aero frame with a very narrow down tube this time.

*Please note that all information might be changed before the release.