Technical Information Pages for the Restoration of the heavy military bikes BMW R75 and Zündapp KS 750.

Herausgeber:  ERSATZTEIL- DIENST   Hans-Peter HOMMES       D-41748   VIERSEN   Tiefenstraße 10       Tel. 02162 - 8100933

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The Zündapp frame

The Zündapp frame existed in different versions.

1. Emblem.
The Zündapp emblem was riveted to the frame head at the front left or embossed directly in the frame.
 

2.
At the back of the frame on the top right a reinforcement plate is mounted.
It existed in short and long.
 

3.
At the back of the frame on the right below a reinforcement plate is mounted.
It existed in short and long.
 

4.
At the back of the frame on the top left a reinforcement plate is mounted.
There was no plate or a long one.
 

5.
At the back of the frame on the left below
 there was no reinforcement plate.
 

6.
On the top of the frame there can be a support for the spray can.
When Holder than   2 x 6,5mm bore.
 

7. Entstörschild to the right on the top frame.
 

8. Entstörschild to the right on the frame towards the sidecar.
 

9. Knee pads.
They existed according to factory specifications only up to 603 340
 

Check the bike frame carefully before the restoration if it is not bended.

If the frame has visible traces of an accident, it has to be completely measured and adjusted in a specialized garage.
The easiest way to check if the frame is warped is to mount the engine, transmission and rear wheel drive in the frame.
The rear axle must be easily screw-mounted to the rear-wheel drive that is mounted in the frame.
The cardan shaft must be in a maximum lateral deviation of 2-3 mm from the line of the rear-wheel drive and the transmission.
If this is not the case, the frame has to be completely checked and adjusted.
Lack of height is compensated by adding shims under the gearbox.
 

The BMW R75 frame

8 out of 10 checked BMW R75 frames had to be adjusted because they were warped.
If the frame has visible traces of an accident, it has to be completely measured and adjusted in a specialized garage.

The installation of the engine, transmission and rear wheel drive in the frame is just one way to check if the frame could be warped.
The rear axle must be easily screw-mounted to the rear-wheel drive that is mounted in the frame. 
However, it is not yet determined whether the main frame tube is straight and everything is at right angles to the steering head.
 

-------A first test whether the main frame tube is warped, can be made as follows:
Replace the bolts for the front and rear main pipe by two longer rods equal in diameter.
By aiming above you can already see now that whether the two bolts are in the same line or if discrepancies exist.
In addition, the bolts must be at an angle of 90 ° to the steering head.

It makes more sense to check the frame completely in a device.
When assembling the bike there is nothing more annoying than to note that the frame is bent and everything needs to be dismantled, adjusted and repainted again.

Check the bike frame carefully before the restoration if it is not warped.

Errors crept into the workshop manual for BMW too. 
The third attachment point for mounting the rear wheel drive is missing.

We offer: spare parts + accessories + repair for engine, transmission, etc. of the Zündapp KS 750 and 600

We offer: spare parts + accessories + repair for the BMW R75 and Zündapp

H-P Hommes Ersatzteil-Dienst
Ersatzteile + Instandsetzungen
repairing + restoring

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