The BME (98, 100, 102, 105) twins used to be based on industrial cylinders and pistons adapted to their crankcase. They were the lightest engines for their size. They were not the most powerful engines - DA and 3W were stronger. They also had some issues with very slow service work (+6 months to get an engine repaired).

They have just recently released the BME-110 which is based on their own design of cylinders and pistons. The few that have them say they are as strong as a 3W-106. If BME improves their service turnaround time, and keeps their price competitive with DA and 3W, and the motors prove to be reliable, then they will become more popular.