I like Bob's idea of cutting the bicycle material to fit.
This link is currently working:
http://www.amazon.com/Bell-SOLID-NoM...ats+bike+tubes

The BGA wheel also looks good. Most others are meant for use on an interior floor, and won't provide much shock absorption on hard rough ground. Recently thrown two different ones away.
Jim

On Friday, September 26, 2014 4:08:36 AM UTC-7, Gavin Short wrote:

The British Gliding Association is now selling flat-free tail dolly wheels.

http://www.bgashop.co.uk/index.php?_...&productId=244