Sunday, November 11, 2012

Front Subframe Installation

This evening, I finished the installation of the DMC subframe on my '83 R100RT. I removed the lower faring on the left side of the bike and removed the two engine mounting nuts. The picture on the right shows the subframe attached to the rear engine mounting bolt. I still need to put the exhaust hanger back on the bolt but I wanted to see how it fit. The loose cable above the frame is the spare clutch cable that I ran before my trip last summer.

Here is the front engine mounting bolt inside of the sleeve on the subframe. The wall thickness of my 19mm socket was too thick to fit inside of the sleeve to reach the nut. I'll need to pick up a thin-wall 12 point socket to tighten the nut. It turns out the the bolts were long enough to accommodate the thickness of the subframe and I didn't even need to remove the Brown sidestand that shares the rear engine bolt on the left side.

The upper mount is a strap clamp that fits over the frame tube and is just below the bottom of the faring. I may end up grinding a bit off of the faring flange for more clearance if it is needed. As it is, there is about 2mm between the eyebolt and the fairing. This was the most challenging part of the installation so far as the heavy metal of the strap needed to be bent to fit over the tubing then clamped to install the two bolts. It seems to me that the eye bolt is a little long. Either that or I have it installed wrong.

I did pick up hardened flat washers for the rear subframe mount on the left side. This is actually where Jay from DMC had mentioned I may need to add some shims due to a slight difference in width and he was right on. As you can see, the subframe hangs pretty low and would really limit how much you can lean to the right. Last summer, I ended up scraping the rear of the brake pedal and the front of the valve cover on roads in Oregon. I guess I won't be doing that again. Anyway, the subframe is essentially installed except for tightening the engine mounting bolts and time to move on to the side car. At least after I get back from Barrow and hear back from DMC.

Monday Update - I did hear back from Jay at DMC and he mentioned that I can trim down the eyebolt on the upper front mount. I wasn't sure I had installed it correctly. He also mentioned a list of items I would need and identified the type of lower mount that I had as they produce a couple of different models. Next weekend, I will remove the front sidecar mount and package it for shipping. I also need measure the width of the frame rails at the rear of the sidecar for a new crossmember and mount. It may be simpler if I remove the body from the frame for a while. It looks like it's coming together.

The steel body tub of the Cozy is suspended on the frame using six rubber rings. The existing rings are cracked pretty badly but I found a supplier of Cozy parts on the Internet, After looking at the my pictures, I really should clean up some of the dirt that is hidden behind the fairing and still thinking whether or not I should cut the lower fairing for the sidecar mountings. It looks like it may be pretty straight forward.


  1. Dang Richard, you've managed to scrape the valve covers on turns?! You must have been leaned way over! I'm impressed.


    1. It was really a shock when it first happened. After that, I moved my upper body more into the turn to keep the bike more upright as suggested by ChrisL. I got a lot of mountain road practice on my trip last summer.

  2. And so ... what do you plan to do for fun when this project is done. I admire your mechanical competence and perseverance but you lost me just after the ...DMC subframe...All this for a side car, but what I really want to know, does it come with a plow?

    1. I don't know what the next project may be. For me, this is both a relaxing and challenging activity. And I have not heard of a plow option though. If you want to plow with your motorcycle, you could try this. A 3WD rig in the snow..