Topeak Folding Trolley to Brompton Luggage Block Adapter

thingiverse

This is a shim that adapts a Topeak folding grocery trolley (My favorite rolly grocery basket thing) to a Brompton folding bicycle's luggage block. For this project, I purchased [an injection-molded luggage block adapter](https://www.ebay.com/itm/carrier-block-adapter-for-Brompton-Bike-bag-Bicycle-Accessories/164397149808?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2060353.m2749.l2649) for the Brompton off of Ebay since that has to be a part with a lot of tensile strength--something that's hard to get in a 3D print. I used stainless T-nuts on the inside, with ⅛ " thick aluminum plates running between them. The telescoping aluminum handle of the trolley provides the majority of the vertical strength, so two plates running horizontally between the bolts was fine. I didn't even have to drill new holes--the ones pre-molded into the basket lined up perfectly. There was a bit more flex than I liked, but upon examination I realized that was due to the gap between part of the aluminum handle and the plastic wall of the basket. I just slid in another piece of the ⅛ " aluminum and it stiffened things up considerably.