I have a .10 in mine with the muffler extension. It helps a little, just a little. My Bee is about twelve years old now. I gone through two sets of Trexlers over the years, and got tired of trying to keep them inflated, especially the tail wheel. I got some Dave Brown 4" wheels put them in my drill press and spun them to take the edges off to make them round like the Trexlers. I put the Trexler hub in and now I have fake Trexlers that I don't have to inflate.