I wanted to upgrade by favourite old Gazelle bike to ebike as I love my old bike and do not want to get rid of it. The transition was very smooth. After removing the old front wheel, the assembly of whole kit can be done in 15 to 20min. II am very happy with the performance. I felt that power is much better compared to other established brands. This could be due to lower overall weight of the bike. Lower weight also makes the bike easy to move around while parking or in your storage. The wireless sensor or remote removes the clutter. Charging is super easy, I can charge without removing the battery from the bike in my garage. The charger is compact and one can still make use of back carrier, which is mostly not utilized in standard ebikes due to battery in back carrier. There is a room for improvement in the Instruction Manual, it can be more visual with clear pictures. The Vollkit App's UI is user friendly. Over the air update feature is really cool. Vollkit retrofit ebike kit was the perfect solution and I have best of both the worlds: keeping my favourite bike with the latest ebike technology.