Been a busy weekend for me with domestic type stuff - needs to be done as I am heading off on my week long 3,500 km round trip to the Oz MotoGP round at Phillip Island this Wednesday morning, so a bit slow with the tank bag photos.
I've had my BMW K1100 tank bag since 1998 and it has been great. I only acquired the K75 a couple of years ago as a project bike from a wrecker and had it on the road since early this year. A few weeks ago while contemplating this next trip I thought about trying the tank bag on the K75, but being a different tank the brackets that fit on the K1100 tank can not be mounted on the K75 tank. After looking at the bag base section sitting on the K75 for a while I worked out a method of securing the bag base to the K75 tank which I believe will work for me - please note that I have not toured with this setup as yet; it is only a trial fit-up.
For those not familiar with the BMW bag base (look closely and you will see that I made a "saddle blanket" of two layers of felt that fits under the base to help protect the tank).
The front end clips over the front edge of the tank immediately behind the steering head. I think other brand tank bags use a strap around the frame at the steering head.
These tank bags are the full triple stacker sandwich about 400 mm high. I have only ever used the top and bottom layers. I reckon you could tour for a month just in the tank bag if you used it all.
The two tails on the base have stretch sections with a hook on the end which connect to matching brackets mounted on the lower rear edge of the tank in their natural habitat of the K1100.
Since the K75 does not have that facility I threaded a webbing strap through the small gap at the end of the elastic stretch section where it joins onto the metal bracket and then around the pin welded on the frame which I think normally holds the rubber for the sidecover to mount to. Note that my K75 is a work in progress and will not be given sidecovers. On other bikes a different attachment point for the strapping my need to be found.
The strapping used for this trial photo was 35 mm wide. The first try was with 25 mm wide and the narrower strapping pulled to one side of the slot I fed it through. I intend to get some 40 mm wide if I can which will be a neat fit. The strap and my "saddle blanket" will protect the tank from being scratched (I hope) by the metal hook on the end of the tail.
Due to the difference in curvature between the two tanks the fit of the base to the K75 at the rear of the tank is not as good as it is on the K1100 but I'm sure it will do since it will save buying another bag.
Hope this little gallery gives others some ideas.
Cheers