La Macchina - let's improve a sidecar (part 5.1)

 So La Macchina hasn't even accumulated 10km, but it was already clear that the current setup needed a lot of improvement. (To be fair, some of the things shown in the previous post happened after the actual first test ride.)

Number one was the rear upper mount. Even under relatively light loads (no passenger, sidecar empty), it would twist and turn out of position. So the rear mount was changed to connect the upper frame rail on both sides.

Next up where the flange bolts on the sidecar chassis itself. No point in having nice solid mounts, when those bolts were all loose in their holes and couldn't be tightened down properly. 

The next bit I was unhappy with were the actual mounting plates. I am not sure, if they originally came from two different sets or one was just drilled incorrectly, but they most certainly didn't sit flush and square on the ears. Some proper thick-wall angle-profile was employed to take care of things. 

 

Corners need a bit of dressing up etc., but these now sit properly flush on the frame and don't wiggle around. 

As you can see, the elongated hole in the right one and the different lengths between those two don't exactly do it for me... (They do fit to be honest.)

 

The clamps needed no more modifications, so Zinc-plating was the next step.

 

... and painted.

 Next was the delightful task of plugging roughly a thousand holes in the sidecar where stuff had been installed. 

 Followed by paint - gloss black. 

 Which to be honest, really, really transformed the looks of the bike. 

La Macchina - let's build a sidecar (part 5)

Guzzis, from a sidecar point of view, are known for two things: They make excellent sidecar tugs and they are easy to convert. Whilst I wholeheartedly agree to the first statement, I have to admit that while the second one isn't wrong, there are quite a few pitfalls out there. 

 Let's start with the basics: I went with 50cm lead of the sidecarwheel in relation to the rear wheel and a track-width of 117cm. Why exactly these values? First of all, because that's how it seemed that everything would fit rather nicely as is without having to modify the front lower sidecar mount, which I definitely wanted to keep in its original rigid configuration and secondly because I knew that, if I should be unhappy with the setup, I could always change it later. So with a bit of chalk and some long rulers and a measuring tape these dimensions were drawn up and confirmed. 

 In order to pull all of this off, I originally bought a complete sidecar from a friend, unfortunately it turned out to be VERY rusty, but even more concerning, the frame had been altered, because in the 1980ies it was fitted to a BMW. So when a relatively good looking one showed up a mere hundred or so km from the workshop, I commandeered my dad's station wagon and we went to pick it up. The pictures make it look a lot nicer than it actually was, but it wasn't completely rotten...

... and it was an export model. As can be seen from the primer on the sidecar mount. (Not shown is the about 2m long pry bar, which I had to use to break the mount free inside the frame tube.)

One of the enormous benefits of for once using a bike which is quite frequently converted into a sidecar is the fact that you can buy a mounting kit of the shelf. That I ended up only using a single piece of the kit is an entirely different matter. And certainly has got nothing to do with the fact that there's a distinct spectrum of how solidly one can affix a sidecar to a motorcycle and how well those parts fit.

 The only mount I couldn't or didn't want to move around was the lower front one. Thus it was only naturally to start there, because it would also determine the location of all other points. 

The lower rear mount was pretty straight forward as well: Replace the swingarm bolt with the one with ball head, cut the mount off the sidecar, measure and fill the gap. 
 

When I came to the rear upper mount, I had the suspicion for the very first time, that I will probably have to modify both the mounting hardware and the sidecar, as I wasn't overly happy with either of those.

 Making the strut longer wasn't too bad.

But it was pointed in the wrong direction, meaning both vertical struts wouldn't form a pyramid but a rhomboid leaning backwards, which leads to a massive loss in rigidity.

With the mounts vertically, fitting the seat would have meant raising it at the back, which would completely would have ruined the lines of the sidecar. So I made my own clamps and decided to run a rather substantial tube underneath the frame, spreading the load between both frame tubes.

 Downside of all of this: someone has to make all the parts. 

 

You can call me a one trick pony as much as you like, but I sort of knew that I was onto something with the way I designed the clamps. 

 Except two of the bolts would no longer be reachable, if I install the clamps like that. 

To end up with something like this.

 

In reality quite a few of these flange bolts are needed.

 

The clamps could do with being made to look a bit more presentable though.

 

And some thick wall tube to connect those two flange bolts.

 

Which means there's a very, very proper front, upper sidecar mount in place.

 Look even better with the strut mounted, I think.

 Obviously a test ride was due next. But who would have expected that? A tyre made in a country that doesn't exist anymore since 1991, is no good anymore? Well... for the time being, a fresh tube had to do. (And staying below 100kph.)

May I point out that the old girl looks good, like really good?

With the "looks-department" solidly in the bag, the overall performance of the sidecar left a lot to be desired. After maybe 5km it felt like the rear end was sagging already and the sidecar was sitting too low on the motorcycle side or in other words, the large 19" wheel was not going to cut it.