When changing seats on a K bike, aside from swapping the hinges and post over from the old seat to the new seat, oftentimes it is necessary to make some minor adjustments to get the seat properly aligned with the gas tank and tail cowl.

The seat attaches at three points:

A - Front hinge

B - Rear hinge

C - Locking post

The rear hinge attaches to the seat bar. The seat bar is held down by two cap head bolts:

When installing a "new" seat, loosen the seat bar bolts so that the seat bar can move around slightly. Leave the seat post off of the seat for now and install the front and rear hinges with their mounting bolts slightly loose as well.

Front hinge post on right side of frame:

Standing on the RIGHT side of the bike, hold the seat and slide the front hinge onto the post on the frame, making sure that the rear hinge on the seat doesn't scratch the tail cowl paint. Then install the rear seat hinge pin.  Let the seat rotate down and then get it properly aligned with the tank and tail cowl before tightening the seat bar bolts and hinge bolts.

Seat locking post:

Install the seat post, again with the mounting bolts slightly loose.  It has wide holes so that you can adjust its position to align with the seat lock prior to tightening it down.

The seat post is threaded and has a 13mm locking nut (not a locknut) so that you can adjust it so that it's the correct length to catch on the hook in the seat lock.  Whenever you close the seat, always make sure that the post catches on that hook.  If you don't then the seat post can ride on top of the hook, eventually wearing through the hook and causing the hook to break off.

 

Seat Clips:

BMW uses special C-clips for seat mounting. Part number 07129934318 - "Lock Ring."

They like to get dropped and lost on the garage floor and are a PITA to deal with. I put mini neon green zip-ties on them to make them harder to lose and easier to remove/install.

 

 

© 2019 Drake Smith - Please do not use or reproduce this elsewhere.  Feel free to link to it though.