Is tuning allowed?

No, tuning is not permitted. Using a tuning kit or manipulating your Bosch eBike system in any other way will invalidate your warranty and any warranty claims for the purchased bike. As a general rule, using the system improperly will also reduce the service life and risk causing damage to the drive unit and bike. You may also endanger your safety and the safety of other road users as well as incurring high personal liability costs and even criminal prosecution as a result of accidents attributed to tuning. Bosch eBike Systems therefore asks that all riders and providers refrain from tuning eBikes.