This is my second go at the new(ish) Sachs Airsal kit, last time I used a 14mm round bing, this time I stuck with the largest stock square Bing, and god damn am I impressed, re-geared to 11x28, takes off much like a stock D, so pretty decent, Estoril welded up to 32mm stock header, hits 50mph on the dot, great sleeper.