I had to take the coaster arm off, peel off that raised piece of metal off the arm
itself (dust cap), and put 1 of the Rubber Strips on the inside and 1 on the outside
of the wheel (spokes) to make mine work.
The reason for this was that the sprocket sat so far in, the chain would rub
the tires. Using that Rubber round strip on the outside (1 only - and the
other for the inside) the chain misses the tire and fender now.
For some reason the Cranbrook has a dust cap underneath the Coaster Arm
- it just about has to come off in order for the mounting to work properly.
Hope this helps, if any questions, let me know and i'll send you a couple of
pics.
af0h - Rob