They were actually extremely useful to the Germans along fixed defense lines like the Atlantic wall. Defense-orientated infantry divisions would include a special battalion (later called a Fusilier Bn) of volunteers which would shoulder special responsibilities in return for improved pay & conditions, and these were often provided with them and held in reserve to respond to any attacks.

Pursuing their general policy of stealing everything that wasn't nailed down and lots of stuff that was as well, Nazi Germany practically stripped the continent of bikes. To this day, Dutch football fans jeer their German counterparts with chants of "Give us back our bicycles."

The Japanese used them extemelly effectively too. In fact, the battle at Singapore was only possible because the Japanese were able to quickly move large numbers of troops.via.bicycles.

I can't quite remember off the top of my head but I believe that the allied forces weren't expecting an attack from land. The Japanese attack caught them off guard and both sides fought to a stand still.

Basically, Japan's use of bycicles gave them a huge advantage on that front.

Please point out my mistakes this is recalled from a undergrad report I did awhile back now.