Designing for Kids: Safety
We could wax lyrical about the safety benefits of good steering geometry, how we use bungs behind bungs on our handlebars, the lack of sharp edges on our belt drive system this article is focusing on how some basic but sensible engineering choices ensure our bikes are durable and won’t fall apart.
We’ve seen a few product recalls on kids bike over the last few years regarding safety issues with forks. All of these have been down to the way the steerer tube is attached to the crown of the forks which the legs of the forks are then welded to.
The standard practice in the industry is to have a steerer tube that is attached to a tube which forms the crown via a press fit, the legs of the fork will then be welded to this crown. The problem that arises is that if the press fit isn’t correctly toleranced the steerer can come loose from the crown. Obviously, this is extremely dangerous potentially rendering the bike without steering or in a worst-case scenario allowing the front fork and wheel to completely fall off the bike during use.
There’s nothing inherently wrong with a press fit steerer, if it’s done correctly, in fact pretty much all high end suspension forks are assembled in this manner. However, many of these forks cost more than a complete high-end children’s bike and as such are made to higher tolerances and have designs featuring machined steps to ensure the steerer can’t pull through the crown even if it does come loose. These more complicated and accurate designs aren’t really cost effective for a children’s bike especially when a couple of basic and cheap options can be used as an alternative.
At Black Mountain, we ensure the issue described above simply can’t happen to our forks with a belt and braces approach. Our forks and crowns are either a single piece so can’t feasibly be separated or on our other bikes where dimensions make it unfeasible to have a single piece crown and steerer we use a press fit steerer and crown but fully weld them together to ensure that they cannot detach.
It’s a simple and more costly solution than most brands have been taking but it ensures your child’s safety.