The built-in Racktime luggage rack fits nicely into the Stromer design, but does not always meet the needs. With a Maximum load between 17 - 22.5 kgDepending on the Stromer model, you can load a lot, but the storage space is rather small.
You can find some creative conversions on the net which are more stable and offer larger packing areas. (li.o. and others from McPringle)

There are also commercially available conversions or additions for more loading space, such as 'PACKI the bike basket' from velokiste.ch

Another option is to print an enlarged edition in the 3D printer using the old Snap-it adapters can be mounted on the Racktime if required. A version with the correct holes (W x H = 100 x 195mm) can be found for 3D printing at Thingiverse.com here. The plate would have to be optimized for fastening openings for tension belts and/or weight savings.
