When you’re out riding, how many times have you wished that your saddle could easily convert between a single seat unit and one that could take a passenger? If you always ride alone and never take passengers, then this probably won’t affect you—but we’re going to guess that a lot of people have been in this position more than once.
Over the decades, different OEMs and aftermarket accessories makers have come up with a variety of solutions to this problem. For the most part, these can be broken into three distinct categories: Single seat all the time, tail cowl that matches your bike’s existing bodywork to cover the pillion part of your two-up saddle, or a two-up seating solution that you ride with all the time.
What if there was an adjustable-length saddle option instead? That’s one thing BMW engineers have been working on in the early 2020s, as evidenced in a patent application filed with the German patent office in October 2021 and published on April 20, 2023.
Gallery: BMW Length-Adjustable Saddle Patent Drawings
As BMW describes the device to be patented, it would consist of two independent seat portions, with a front part that would always be actively supported, upon which the rider would sit. A second part of the seat would then slide out from the back of the first part upon actuation, while also maintaining support for the person or item secured to the pillion seat to occupy.
The patent language, as is typical of BMW patents in general, goes to great lengths to describe the details of how such a device might work. Actuation might be manually adjustable, or it might be electrically, hydraulically, or even pneumatically adjustable instead.
Since the two seat components would operate independently of one another, with the front part always active, the second part might be able to fold up into a slightly raised support lip at the rear for a solo rider when not in use as a full passenger seat. Additionally, the saddle might have several intermediate settings between full retraction and extension, which could potentially be a useful ergonomic device for even solo riders. Most importantly, it would also be lockable in each position, so the adjustable saddle couldn’t slide out of its designated position unexpectedly.
While the first, front part of the seat could either be fairly rigid in design or elastic, depending on needs, the patent application dictates that the second part should be “designed to be reversible and non-destructively elastic for this purpose, so that it can be deformed, in particular folded, when the seat adjustment device is adjusted, without being damaged.”
That of course makes sense, since theoretically a rider would extend and retract the passenger seat quite often over the lifetime of the bike. Clearly, the engineers have their work cut out for them—but then again, don’t they always?
Incidentally, BMW engineers, as you might guess from the expansive scope of the company, are an internationally busy lot. For example, they also recently filed a patent application in the UK regarding illuminated sewing thread, which was similarly published in early April 2023. It would potentially use fiber optic strands to sew decorative designs on things like, say, future adjustable saddles. We’ll link that bonus patent in our Sources if you want a closer look as you imagine your light-up, color-changing BMW saddle roundel alerting drivers behind you to your presence.
Sources: World Intellectual Property Organization - Retractable Saddle, WIPO - Illuminated Sewing Thread