Cadence meter for the Shimano Ultegra Flight Deck 5601? Is there a cadence meter available for the Shimano Ultegra Flight Deck 5601? Or is there a good alternative option for measuring cadence without changing the flight deck setup?

The Shimano Flight Deck computers use 'virtual' cadence. There are switches fitted to the shifters that tell the computer which gears you have selected. The wheel sensor tells the computer how fast you are travelling. The computer works what your cadence is from there.