I have a very restricted stock of large shank mouthpieces. While I use the SM4X on my euphonium this one also works best for solo purposes on my old Besson bassbone. Better than the 1.5G (which I use in Bigband) and the solo mouthpiece my bone came with (don't remember brand and solist's name). But I agree, my Wick mouthpieces are not the best fit on my tenor trombone.