aerotrunk test

[techhead]

Last week I received my Angletech Aerotrunk. Previous posts here have discussed what speed gain the Aerotrunk might give.

I conducted a roll down test on a 900 metre hill with and without the Aerotrunk using water ballast to compensate when the trunk wasn't attached. A Garmin 305 GPS cycle computer was used to collect the data.

The results show that the Aerotrunk adds speed starting at 30 kph and at the maximum speed of the rolldown the Aerotrunk adds 3 kph. So max with the 'trunk is 59 and without it 53.

 

[bobbyOCR]

cool. I can't imagine it on anything but a recumbent though.

 

[techhead]

cool. I can't imagine it on anything but a recumbent though.

I agree.
My use is for short touring or long day trips where I need to carry my wifes extra coat because she doesn't like cluttering up her Orbea Dama!

The bright yellow bag makes the P-38 a lot more visible from behind.

Doing the test was interesting but what was more interesting was using the Garmin 305 as a data collector. The roll down runs charted elevation and speed.

That would be useful for fine tuning the tuck position on any bike. It's like having your own wind tunnel where the hill is the 'tunnel' and the 305 shows any aero advantage.

You can pass the 305 aroung a group of cyclists because being a GPS unit it doesn't need a wheel magnet. That means it's possible to test a variety of bikes or equipment positions by simply slipping the unit in a back pocket.

 

[bobbyOCR]

I agree.
My use is for short touring or long day trips where I need to carry my wifes extra coat because she doesn't like cluttering up her Orbea Dama!

The bright yellow bag makes the P-38 a lot more visible from behind.

Doing the test was interesting but what was more interesting was using the Garmin 305 as a data collector. The roll down runs charted elevation and speed.

That would be useful for fine tuning the tuck position on any bike. It's like having your own wind tunnel where the hill is the 'tunnel' and the 305 shows any aero advantage.

You can pass the 305 aroung a group of cyclists because being a GPS unit it doesn't need a wheel magnet. That means it's possible to test a variety of bikes or equipment positions by simply slipping the unit in a back pocket.

That is an excellent point. Using the same slope, same weight, same day and different positions + the Garmin's range of features could give everyday cyclists the access to position perfection. But, if used on a time trial bike, the efficiency of each position still needs to be tested.