I did two tours with them. The hotels were nice enough, and the routes were mostly nice, except for…read moresome long-term trail closures on the routes that we had to figure out detours for.
The main problem with the trips was the rental bikes. The secondary problem was the (lack of) customer service.
The first tour, the shifting on the bike I received didn't work correctly, because the bike hadn't received necessary maintenance. After riding the bike for two days, I emailed Dutch Bike Tours requesting a new bike. The response I received essentially said, "We took so long to respond to you that we assume you've solved the problem yourself." In fact, the bike got progressively worse throughout the trip.
On the second tour, the shifting on the bike I was given broke after riding less than 20 km. I had the bike mechanic from the bike breakdown company come to try to fix the bike, and he said that it was broken in a way that he couldn't fix and told me to call Dutch Bike Tours to request a new bike. I called the next morning, and the hotel gave me keys for a different bike. Unfortunately, the new bike was also not in good repair: the handlebars were twisted off-center, and the chain was badly in need of maintenance. I tried a third bike, and it had the same problems as the second bike. I realized that all the rental bikes used by Dutch Bike Tours were in bad condition, and I hoped that the bike simply wouldn't get worse as I rode it.
The next day, after being annoyed by listening to a squeaking bike chain all day, my husband encouraged me to see if the hotel had any other bikes I could try. They did, and the bike was actually in worse condition than the one I was already using. The hotel then contacted Dutch Bike Tours about having another bike delivered, and apparently it was delivered, but no one notified me.
Not only were all the rental bikes I tried (5 in total) in need of maintenance, but even when I tried to work with Dutch Bike Tours to get a well-maintained bike, they weren't able or willing to supply it.