In addition if you are riding a bike, you are Fietsen and you are referred to as a Fietser. If you are all dressed up in Lycra and riding a Wielrenfiets then you are a Wielrenner. Notice the lack of mountain bike terms, we simply there aren't really any mountains in The Netherlands unless you include the Dikes and Sand Dunes. Mountain is Berg but the Dutch simply use the English term of Mountain Bike.
One thing you will notice about bikes in The Netherlands is that they are not into flashy bikes. Simple bikes, the rustier the better, were the ones seen the most. There were also a lot of electric assist bikes as for many this is their primary mode of travel.
Here are the main Dutch brands I saw there