The Dolomites Bike Day is a welcoming event. The roads are free from traffic, and you can opt for any bike you'd like. Yet, there are a few things to remember for each category.
Road bike
The best option for climbing and descending while enjoying the scenery. The route is 100% paved and with steep gradients, but no extremes. Make sure your bike is working well before using it, though.
MTB
Not the recommended bike for the day, but you can still use it. The possibility of having smaller gears at your disposal will be appreciated when the roads are steep. And it's common to see faster mountain bikers than roadies!
Gravel
The Dolomites Bike Day is an excellent opportunity to test your gravel bike for a long trip ahead. If you have a big bike packing adventure planned for the year, you're welcome to test your steed at the Dolomites Bike Day.
City bike
Don't think that the Falzarego is comparable to your daily commute. However, if you want to use a city bike, make sure you check your gear ratio and that your fitness level is in par with the challenge.
E-bike
If you feel like your fitness level is not up to the Dolomites Bike Day, an e-bike may be the solution to help you participate and enjoy the day. In several of the local rental outlets, you can find both e-road and e-mountain bikes. If you haven't used an e-bike before, ask for professional help and be moderate with its use. The battery may not last for the whole day if you over-use it along the course.