TromboneChat

Hello

So, the question is in the title... I can't find any place to buy 0.487 inners for my Besson... I called the local workshop and they also struggle. Any idea ?

The most important dimension when replacing inners is not the bore, it's the stocking diameter. Then the length (although tubes that are too long can be cut off), and finally the bore. You may end up having to use .485" tubes (assuming you can find them to match the other dimensions).

The Allied catalog shows an inner tube with .485 ID, stocking OD of .522, and length of 30". Perhaps that will work. You tech should be able to order from Allied.

Thanks a lot for the tip, i'll tell him tomorrow

Effectively, as JohnL says, we tried a 0.487 bore inner from another trombone and it didn't even fit in the outer slide... Now we try to get something from Kühln & Hoyer, as we are in Germany. Otherwise, he knows a company than can pull inners of every custom size, but they cost 300€ for both... For a 200€ trombone it's a bit much but well, it's my main instrument now.

So after testing, it just appears that the King Tempo (2B like) inners fit perfectly in the Besson outer slide...