The Blanik has a 350 x 135 tire. Apparently the company that used to
make an inner tube to fit this tire has stopped doing so. The local
Blanik operator has been told that the appropriate tube is 500 x 5.

In the last week, there have been 3 flat tires on the Blanik. Each
time, there was a 1-2" rip in the tube by the stem. Apparently the tire
is moving on the rim when the brake is applied, and this pulls the tube
and tears it. As far as the reason the tire is moving, it apparently is
because the 500 x 5 tube is either too large or too small.

Any other Blanik operators out there with this problem? Any solutions?