Q: I was wondering if you guys could help me with something? I happen to own a 2005 Aprilia Caponord and recently decided to fit a top-box because I’ve always just strapped things to the original rack. Not such a good idea when it rains though.
But when I took the bike out after installing it began to weave when I passed 160km/h. It’s not too bad but it can become a little unnerving at times, especially when the wind gets strong.
So why would just fitting a mere top-box have such a bad effect on the handling of the bike and there seems to be no mention in handbook telling me not to do so? Thanks for your time.
Francois Berni
A: It’s all down to nothing more than changing the aerodynamics of your bike. I’m sure there’s nothing wrong with bike itself.
You see normally and before the top-box fitment the air will swirl around your body and be swept away. But now it will be disturbed by the top-box and perhaps cause a form of vortex behind you, which has obviously upset the bike. Have you tried it with a passenger because I’m convinced it will be better, because the ‘hole’ will now be filled?
All bikes are tested in a wind tunnel and not with a top-box unless included with the original bike. There are simply too many top-boxes out there to test them all on each bike at high speeds. However most manufacturers, including Aprilia, will tell you not too exceed stipulated speeds when accessories, like this, are fitted. So you just might want to read through your manual once again?
