CX 500 A/B/Z/Eurosport Frame Measurements

Whilst I had access to a pair of Z/A/B and Eurosport frames, I measured up the distances between the engine-to-frame bolt holes. There are differences between the two, showing that mounting a Eurosport engine in a Z/A/B frame, or vice versa, is no easy task.

Apart from coping with the different frame mounting points, there are very significant other problems, such as:-

- the Euro engine being a tad longer than the ZABC;

- the Euro has transistorised ignition and the ZABC has CDI, which is entirely different;

- the ZABC engines have a top mounting bracket just forward of the carburettors (the "triangle plates") which physically will not fit in the Euro frame, unless the Euro rear casing is fitted, which means drilling a hole for the manual cam chain tensioner locknut and somehow arranging for the ignition pickups to work.

But - I know it HAS been done, because I've seen a 500 ZAB with a 500 Euro engine.

However, these photos may help anyone contemplating the task.

ZAB frame showing the 6 mounting holes and the various distances.

Closeup of the rear subfrane mounting points. These appear very similar, or identical, to the Eurosport rear subframe.

Comparable photo of the Eurosport frame. Note the absence of the triangle plate mountings.

Eurosport rear subframe.

For the 650 Eurosport, the measurements are:-

A-B 7cm
A-C 49.5cm
A-D 58.75cm
B-C 43.5cm
C-D 13.5cm &

DISTANCE APART

C1-C2 23.4 cm
D1-D2 22.2 cm

Thanks ro Pete Harker for these figures..

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