It’s been a long time in coming, and feels fairly momentous: for the first time in 8-1/2 years, I have the crankcases, the wheels, and suspension all solidly bolted to the frame. Just as importantly, the alignment of the engine is spot-on.
Compared to Bultaco’s original method of mounting the engine, mine is much heavier, more complex, and probably not much more rigid. All this so that I could use a YZ125C monoshock swingarm—something I have long since abandoned!
To be fair, I should point out that my arrangement—unlike the original mount—also turned out very nearly un-assemble-able (well, at least without removing the swingarm). Fortunately, I found out that I could, indeed, get all the bolts slipped into place by orienting everything just so, and following a specific order of assembly.
As you can see above, I still have to make the spacers for the lower rear mounting bolt, as well as source proper hardware to replace the mismatched collection of bolts I have now, but that’s minor stuff. The big, blurry question about how to mount the engine has been answered.
I’m curious how much effect rubber mounting the rear of the engine will actually have, considering that the upper and lower front mounts are still solidly bolted to the frame. At this point, I mostly hope it won’t have any unintended negative consequences. But I’m done worrying about how good this bike will be. I made lots and lots of ill-considered decisions early on, because I didn’t know better. (It’s amazing how much quicker, easier, and better the Aermacchi is going together, now that I have a lot more knowledge, plus the proper tools and equipment.)
