My XZ-MZ: an XZ550 with an MZ Superelastik
sidecar
XZ-MZ:
note the front end.
When I bought my first XZ, I
started wondering why it had a trailing front axle: an axle behind the middle of
the centre of the front forks. I had seen this before: the Dowty
Oleomatic front fork fitted to several English
motorcycles around 1948. The trick was that you had a good solo geometry with
the axle in the back position and a good sidecar
geometry with the axle in the front position.
Drawing from
Motorcycles
and how to manage them,
From the beginning of
XZ-ownership, I wondered what would happen if I put the left fork in the right yoke
and the right fork in the left yoke. You can slide out the front fork with the
wheel after loosening the clamps, speedometer cable and the brake lines, turn
around the total, refit everything and ride. The trail is originally 118 mm and
by turning the front so that the axle is up front it becomes ca 53 mm. As ca 40
mm is an ideal value for sidecar-driving, it is no wonder that the XZ with 53
mm trail has a good road-behavior. I have a steering damper, but it seems
unnecessary for this three-wheeler and I have not fitted it up to now. I also
did ride the motorcycle without sidecar with the axle in the
“sidecar-position”: very, very funny, so light steering. I expected dangerous
behavior, but up to ca 100 km/h (60 mph) it rode remarkably well, no signs of
wobble, but I kept the handlebars well in my hands. It really has a charm of
its own, and I will try this again to investigate the bike’s behavior more
fully, but of course, for everybody including myself, be aware that this may be
extremely dangerous! A high-speed wobble may throw you off the bike. I
do this at my own risk and I do not recommend this to anybody. If you do this,
you do this at your own risk!
Two problems remained:
One problem I experienced
was that the speedometer, now driven at the right side of the front wheel, did
not work and that the odometer counted backwards. I took out the wheel
including speedometer drive, and brought it back to the original position. The
wheel is fitted in the normal position (speedometer drive left). The axle is in the new position to fit the turned-around
fork legs. The wheel fits but it is in an off-set position of 35 mm. I
cut 35 mm from the bushing and made up a “bushing” of 35 mm flat washers to
compensate for the difference, and fitted that to the other side. This brought
the wheel and brake disks back in the right position. That was kind of an easy
fix.
The second problem was that the front fender,
mounted backwards looked strange. Turning it around “to the normal position” is
not possible because the front wheel is ca 6 cm more to the front now. So I
kept the fender in the backwards position, cut the front part to look kind of
normal and also took out part of the center because I had a front fork
stabilizer that fitted but the fender was in the way of this part.
I consider a strong
stabilizer between the legs absolutely necessary for sidecar driving (and of
course tapered steering bearings) and I did cut a slice from the front fender
to fit this non-XZ part that spent the first decades of its life on a BMW.
The wheels: I obtained a 16”
rear wheel from an XV 750 and a 15” wheel from an XV700. The 16” wheel has the
same brake and it fits right into the XZ rear fork.
The rear wheel is from an XV750, 16 inch. The gear
change and footrest are of an 1982
The 15” wheel is a different
story. It is much stronger, has a larger brake, wider brake linings, and
certainly is the wheel to go for. However, it is ca 12 mm too wide to fit the
XZ rear fork, that means, it fits but it cannot be slided
in. It is just those mm too wide but I definitively want to use this wheel
because of its strength, better brake, wider tire. I still am working out how
to fit this wheel, and what car tire is best suited for this wheel. These
smaller wheels also results in an attractive reduction of the overall gearing:
see XZ gearing topic elsewhere on this website.
Even more reduction can be
obtained by using an engine with the gear wheels of an XZ400. I have Euro gears
(34/72) at present, and USA-gearwheels (33/73, increase of revs at the same
speed of ca 4,5%) from my Canada bike as a spare, but I obtained a set of gear
wheels of a XZ400 (from Simcha who was so kind to
take the gear wheels out of his XZ400, a bike imported secondhand to the UK).
That set 31/74 gives an increase of revs at the same speed of 12,75% over the
Euro gears I have inside now).
Further the high-lift
handlebars, footrest, brake pedal and gear change of the
Further changes: the plastic
coolant container is fitted to the YICS bolt because the sidecar upper rear
ball-joint connection is in the way of the upper fitting of that coolant
container. The YICS moved to the left side of the engine, a not unattractive
location. The lines are slightly longer, still it behaves better with this YICS
than without one.
A 35 Amp battery of a small
car is fitted in the sidecar boot (see below left). The R/R with bolted on computer
cooling body (no fan, just larger cooling area see below right E.C = Extra
Cooling body) is fitted in the battery compartment. This compartment has a few
extra holes in the front and back to bring more cool air inside.
An MZ Superelastik
sidecar of the 80’s was chosen because it has a sturdy three point ball
connection, because it has a stabilizing torque bar between the sidecar fork
and the rear fork of the motorcycle, and because a passenger has easy access to
the seat. The swinging front is a beautiful construction and it is nice,
especially for female passengers. I like this sidecar also because of its good
suspension (indeed it is superelastik).
Left: MZ sidecar; note that the plastic bottle with
coolant is fitted on the YICS bolt.
See photo of detail below.
Right: the connection between sidecar and XZ. Blue
arrow: the main connection by ball-
joint. See photos below that show the front-
and backside of this connection point.
Yellow arrow: top connection by adjustable
ball-joint. Red arrow: stabilizer between rear
fork and fork of the sidecar. There is one
more ball-joint at the upper frame near the
steering head.
The plastic reservoir is fitted between a metal strip
and the YICS bolt.
Also, the square nose suits
the square styling of the front of the XZ remarkably well.
Changes still wanted for the
sidecar XZ: one silencer, only at the left side, not between the XZ and the
sidecar.
A plastic cover that
protects the oil cooler, like the protection of the coolant radiator.
An air supported front fork:
the spare bike has front forks with air valves so that will be an easy change.
For best braking I want to
use the big brake disk + caliper + front fork leg of the Canada bike and at the
other side the smaller, normal second disk + caliper + front fork leg. I hope
this can be done.
Above left: a 30 mm ball is one of the main
connection points for the sidecar. It is fitted
with a large nut (blue arrow). There is
also a steel reinforcement plate at the backside
of the aluminum plate. The red arrow
indicates the connection for the spring of the brake
light switch.
There is one other XZ with
sidecar, as far as I know, in
XZV2