What's "Rabbity"?

The core book gives it as a downside a motorcycle might have, but I haven't been able to easily find a definition of what that's like. Downsides like "guzzler" are obvious, and "picky" is defined as "needing specific parts/special care", but I'm really drawing a blank on "rabbity". Sounds to me like the shocks might be bad, or that it doesn't stop or idle for long (i.e. acts like a scared rabbit), but are there any savvyheads out there who know more than me?

My educated guess is that the accelerator is twitchy, making the 'cycle prone to sudden drops or bursts of speed, especially when getting up to optimal cruising speed.