I was thinking about this the other day mainly, in terms of keeping any 'sharpness' on a bike up to speed.
How about getting off-road???
For example - going to an off-road centre for either a go of - trail / trials or even (god-forbid) some gentle Supermoto if anywhere is daft enough to do it!
Indoor mini-moto also sprug to mind but I just know my hips/back/knees/wrists would never cope for more than 3 minutes - LOL - much the same as some other activity really!!!
Franko