BMW R45 R65 R80 and R100 Airhead Power Upgrade from Seibenrock

My thoughts on the BMW Siebenrock power kit 860cc for BMW R45. This kit increases the power and is made for most BMW Airhead models from the R45 and R65 to the larger R80 and R100 motorcycles. Available from here: https://www.louis-moto.co.uk/artikel/...