/6 seat modification

/6 BMW motorcycle seat modification

by Duane Ausherman

This article is specifically for the models R60/6, R75/6, R90/6, and R90S, but with some fabricating a part or two, it has been applied to other models.  See the note below.

The stock hinges on the seat are well known to break.  The stock parts are expensive and hard to replace.   Why not make things so that they don’t break in the first place? They were made that way, and with time things tweaked, twisted, sagged, and got old.  The design is for the seat to rest on the rubber bumpers around the seat’s edge.  Look at yours.  They have an impression where they have been sitting on the rear frame section for the last years.  To test if the seat is still resting on that rubber piece, stick a piece of paper under each one or one at a time.  Close the seat and see if the paper will pull out.  If too many pull out easily, then some/all of the weight is on the hinge, and it will break.  The easy fix is to wrap black tape around the frame to build it up.  Another fix is removing and tweak the hinges until they allow the weight to rest on the frame again.  That is risky as they could break, and it takes a lot of time.  Do you have another way? I will evaluate it, and if it is well thought out, I will post it here and give you credit.

The /6 seat modification

BMW seats have one weak area, the hinges.  They break off easily and are a real pain to find and replace.  There is another way to do it.  I forget who came up with this mod, but we thank him.  The seat can be modified to lift up off of the bike.  This is a real advantage for the bike with saddlebags.  The entire locking system stays the same.

seatmod1.JPG (65364 bytes)

Here is what the bike looks like with the seat removed.  We will use a hole that is in the rear sub-frame.  It is located on the right side and in the center of the photo.

seatmod2.JPG (40356 bytes)

The parts used

The parts that are used in this mod are all normal parts.

1.  A standard machine bolt with 6mm threads and about 1 1/2″ long.

2.  A short piece of fuel line that is about 1″ long.

3.  A nut for the bolt.

seatmod3.JPG (43415 bytes)

This is what the seat looks like when the three parts are installed.  The nut locks against the seat pan to hold the bolt securely.  The makeshift post drops into the hole in the frame to keep the seat from moving around.  To open, just push the button, as before, and lift the seat up and off of the motorcycle.

While this works with the LWB models, a few people with the SWB have made a plate to attach to the sub-frame.  The plate has the hole in it.

I have been using this mod for the last 25 years, and I love it.  I don’t have saddlebags to get in the way, but it is nice not to have the seat fall back into place and require an opening again.  I also don’t have to buy and replace a seat hinge every few years.

Here is another fix for a broken seat hinge.

Updated 17 July 2022