I *tried* to get some Razorbacks from Jenson but they are currently on 30 day back order.
Already got 2 pinch flats on my 300 miles worn Razorback, last hope would be Mr. Tuffy + Maxxis Extra Heavy Duty 21x80,90/100 MC tube (thanks Rick!). If that fails, then Shinko SR241 2.75-19 on a mc 19x1.4...