A replacement part is available from:
Velos-Mots Burkhalter
Fahrnerweg 6
CH-3045 Meikirch
Switzerland
Price including adapted speedo cable: 120.- SFR/85€ plus shipping
Grimm GmbH
Mechanische Bearbeitungen
Donaustraße 31
D - 72768 Reutlingen
Tel.: +49(0)7121 670329
Fax: +49(0)7121 677121
mailto:info@grimm-gmbh-rt.de
The available size is: 1,5mm x 15,0mm
The gliding band can be easily sanded down under micrometer-controll to the needed size of 1,4(4)mm x 14,5 mm