Owners of early BMW twins are divided into two sorts; those whose centre stand bolts have failed and those whose bolts are going to fail soon. The root of the problem is that on the pre-square air filter models the stand pivots on bushes retained by a pair of bolts which screw directly into the frame. The continued heaving on and off the stand eventually loosens the bolts and the threads in the frame will start to fret. Retapping the frame to the standard thread (M10x1.25) and replacing the bolts delays the evil day, but when I found a bolt lying under the bike only days after doing this, I knew it was time to look for a better solution.
My method goes as follows: Remove the exhaust. Clean the frame threads with a suitable tap. Obtain two longer m10 bolts with an unthreaded section slightly longer than the width of the pivot bush and spring washer. Assemble the stand, screwing in the bolts until they touch the sump. Measure the excess length of the bolts, remove and hacksaw off enough of the thread so that when assembled the bolts have a tiny clearance between their ends and the sump. Depending on how stripped the frame threads are it may be necessary to enlarge the entry slightly so that the plain section of bolt is a snug fit and can be screwed fully home. Find the fattest nuts which can be fitted into the gap between sump and frame. I managed to get a nyloc nut on one side. It’s worth trying a few suppliers, some stainless nuts are available in slightly different widths to make best use of the limited length of thread. Nuts and bolts can be torqued up nice and tight as you won’t have to worry about stripping what’s left of the frame threads and don’t forget to check them regularly.
So much for fixing the pivot, but those of you who have been there will have spotted the snag. Because the nuts occupy the space normally used by the centre stand springs when they retract you can’t use the original arrangement. The solution is as follows. Carefully saw through the weld which holds the spring retaining peg on the right hand stand leg and have it re-welded in the same position but facing outwards. This is the tricky bit as if the peg sticks out too far it will foul the exhaust pipe; too close in and the spring will not clear the head of the bolt when the stand is retracted. The other end of the spring is retained by an extra spacer. This is a standard BMW part and like the original this is fitted to the front engine bolt but on the outside of the frame. (The original spacer remains in situ). The spring is now situated between the frame tube and exhaust pipe. Only one spring can be fitted as the sidestand is in the way on the left hand side but I have had no problems over many thousands of miles of bumpy Devon roads. Compulsive worriers can carry the redundant spring as a spare.
No repair is permanent, but if this mod is carried out at least a future problem can probably be rectified by fitting new bolts, so while you are doing it cut a couple of extra bolts to the right length and keep them under your seat.
