I bought this attachment a few weeks ago. You would think that Hoverboard would make the best possible design for their own board. I was not very impressed. As an engineer, there were a number of design choices that I feel sadly missed the mark. Probably the most significan of which is the idea that the velcro straps wrapping around the board (the most critical part required to make this thing function appropriately) would be at all protected by some thin rubberized plastic that they run through. This is the weakest part of the entire design. These things take a hit from evey possible bump. Just simple experimenting with this thing on the paved back patio tore them apart, and they kept sliding & losening. Maybe a metal covering that could be slid in place could help protect them. You could easily go through a set of straps in about 10min riding this on the road, bike lane, sidewalk, etc. Then you’ll spend another hour walking this heavy thing back to your house. The concept seemed great. The design execution was very poor.
I had the same exact experience and thoughts as you. First off I am no engineer by any means. My first thought with my nephews was to at least use a something akin to a battery bracket lockdown and some softer type bump stops for rudimentary makeshift dampening suspension. still retaining solid points of contact to salvage any efficiency in the transfer of power.
This appears to be universal among these kart things, many reviewers figure out to use zip ties (bonus points for metal zip ties).
I meant to link this in previous post.
These guys seem to have gotten it right. Surprisingly the prices arent astronomical if that’s for the complete attachment.