The Gull-Arm will fit the MC18 fairly easily. You will need to make new linkage plates to account for the different geometry, especially if you use the MC18's 18" wheel. You may find the swing-arm pivot on the Gull-Arm is slightly larger than the MC18 (can't remember off hand) so the holes in the frame may need reaming out a little.

It's a much easier job than fitting a Pro-Arm, that's for sure!

Andy.
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