Joined: Feb 2012
Posts: 19,373
Likes: 5,516
From: Rochester, NY
Bikes: Stewart S&S coupled sport tourer, Stewart Sunday light, Stewart Commuting, Stewart Touring, Co Motion Tandem, Stewart 3-Spd, Stewart Track, Fuji Finest, Mongoose Tomac ATB, GT Bravado ATB, JCP Folder, Stewart 650B ATB
If there's no evidence of a wedge (cotter) pin having been present (a hole through the arm's base) then you might have a Thompson crank. The RH arm is "fused" to the spindle. It won't come off. Instead you remove the spindle from the BB from the HR side to access the bearings. The LH side would be much like any common cottered crank. But with only the one photo we can't really say. Andy.
I see that the OP was able to remove the arm. Good!
Last edited by Andrew R Stewart; 09-15-15 at 07:47 AM.
Reason: Seeing a new post from OP