Conversion to 100 mm wide fork works (Dec. 2009).
You don’t get a 100 mm wide fork from VeloWerk in Schaffhausen Switzerland, unless you go there personally and pay cash :-).
I converted two Dahon bikes (Ciao D7 and Roo D7) to front motor driven electrical bikes. The front motor is 100 mm in width. The fork was replaced by commercial forks with 1” steering shaft, details see below.
Dahon Roo D7, image 1, adapted from here:
http://www.pedelecforum.de/forum/showpost.php?p=49665&postcount=218
Fork conversion:
I widened the inner diameter of the Dahon forks steering tube to 1 inch + 0,05 mm with a lathing machine
and put the new steering tube of the 1 inch fork, image 4 above, into the steering tube of the dahon fork, image 3 above shows the (truncated) Dahon fork at the right.
The 2. image above shows the Dahon steering tube on top of a 1" fork (in this case the 1" fork is grey in color) just before it is inserted into the Dahon frame.
Text in poor english is also to be found here:
http://www.pedelecforum.de/forum/showpost.php?p=46126&postcount=175
Finally I used the red fork to be seen in image 4.. I bought it as "2. choice" because of scratches on the surface, price 10€, sold at ebay Germany, search keywords: Starrgabel, or: KLAPPRAD 20"
technical data (translated/in German)
length of steering tube: Schaftlänge mit Gewinde ca. 19 cm
total heigth: Gesamtlänge ca. 53 cm
diameter of steering tube: Schaftdurchmesser von ca. 25,5 mm
hub(?) width at wheel axis: Innenbreite ca. 10 cm
brakes: Bremsaufnahme V-Brake
max. heigth of wheel: Innenhöhe ca. 29 cm
I guess the following forks are also suited:
prism fork:
http://www.bikestore.cc/product_info.php/products_id/12594.html
and:
http://alles-fuer-das-rad.de/popup_i...866c45b70cc65d
Last edited by Schwipp; 12-02-09 at 10:13 AM.