Not long ago we posted a blog called ‘Are E-Scooters Suitable for UK Roads? The Pothole Test for Safe Scooter Design’ outlining what would happen when big and small wheel adult scooters go over a pothole. Looking at the geometry of the scooters we concluded that the small wheel scooter is far more likely to result in a crash and fall when faced with a pothole.
The UK government recently called for evidence from scooter manufactures on how to safely implement e-scooters and micromobility to the UK. Having already predicted what would happen and highlighting our safety concerns with small wheel scooters we decided that we needed to make our statement as clearly as we could. So we put a big and small wheel scooter to the test!
What is the pothole test?
Using plywood boards we simulated potholes at 3 different depths – 36mm, 54mm and 72mm and attempted to ride over them on both an 8-inch wheel and 16-inch wheel scooter. We did each run with the pothole size at both 400mm and 800mm to simulate the variation in sizes. It’s worth noting too at this point that the average height of a curb in the UK is 100mm.
We chose an 8-inch wheel scooter (Xiaomi m365) and a 16-inch wheel scooter (SwiftyAIR). We chose the Xiaomi because it’s one of the most popular e-scooter models from one of the largest scooter manufacturers in the world, and feel it’s a fair reflection of e-scooters in general.
The Swifty is, of course, our own model and we wanted to put our money where our mouth is. We have honed our design and geometry over the years to make a scooter that is as safe for the riders as possible, so we’re more than happy to put it to the test against others!
Most potholes in the UK are repaired (within 7-28 days) if they are deeper than 40-50mm (depending on the council), so we based our sizes around this.
Our intentions with the test –
We have strong concerns surrounding the safety of small wheel scooters being introduced en masse to the UK. You don’t have to look far online to hear stories of people around the world crashing on small wheel e-scooters resulting in injuries and tragically, sometimes fatalities.
We devised the pothole test as a simple way of seeing how the scooters would do facing potholes of various sizes.
We hope through this version of the test we could show the UK Govt the dangers can easily arise while riding small-wheeled scooters, and how the dangers can be lessened, or even completely avoided by only allowing larger wheel scooters.
The pothole test is not intended as any form of advertisement for Swifty or our scooters. Our primary concern is the safety of the public, and if there’s something we can do to help avoid accidents happening in the UK we’re going to do it.
Obviously as manufacturers ourselves we aren’t going to be without bias, however, we’re sure there are a lot of other scooter brands around that would pass the pothole test as well as the SwiftyAIR did in our video.
We are well aware of the limitations of our test - our rider (Jason) is an experienced scooter rider but is co-founder of Swifty, we are not able to match the exact speed for each run, we are only simulating a head-on collision and the rider is aware that they will be hitting an obstacle - to name a few.
See what the Swifty community thinks about current issues surrounding micromobility from our recent survey!
We are not stating that this is the exact way it should be done; we’re merely showing that even from a small scale run through in our warehouse clear differences can be seen. It’s jarring how clear the results are from this basic setup.
The limitations in themselves can highlight further potential problems. As mentioned Jason is an experienced scooter rider so knew how to brace for these impacts on both scooters, yet he still fell off on different runs. Should this test be recreated with people who have never ridden a scooter (which many who embraced shared e-scooters won’t have) the results would likely be different, and we assume more alarming.
The Results in Brief –
36mm Deep Pothole
8-Inch Scooter – At our smallest height some key observations can be made. Most noticeably the stem of the scooter deflects back and forth considerably after impact with the pothole and the rider’s feet come completely off the deck after impact.
The pneumatic tyres do a good job of absorbing some of the impact, but as there is not much crumple zone in the tyre the shock of the impact can be seen clearly and the result is the rider losing contact with the deck.
16-Inch – Nothing to note in regards to 36mm depth, the tyres of the scooter absorb most of the impact and there is no loss of control. The geometry of the scooter means the rider can position himself better in order to deal with an impact.
54mm Deep Pothole
8-Inch – A main takeaway from the 54mm test is that the small wheel scooter comes completely off the ground after the impact. At one point both the scooter wheels and the rider’s feet are not in contact with the ground, which signifies a considerable loss on control. On the 800mm distance test, the rear wheel of the scooter also bounced up off the edge and hit the rider’s feet.
Other issues noticed in the 36mm test are highlights further too, the stem deflection is more extreme and the rider’s feet leave the deck again, landing back almost on the rear wheel.
It was after the 800mm version of this run that we found there seemed to be issues with the steering column of the 8-inch wheel scooter too.
16-inch – Again the effect on the large wheel scooter is not too noticeable, the frame itself doesn’t change during the impact and the wheels do a good job of absorbing much of the impact.
The rider is able to position themselves in a way to help deal with the impact through their knees and shoulders and not lose control of the scooter at any point.
72mm Deep Pothole
8-Inch – This depth ultimately proved to be beyond the limit of the 8-inch wheel scooter. On both runs, it resulted in a crash and the rider being thrown off. The issues that were highlighted from our previous tests were recreated to a point where our rider was unable to hold on and the scooter was brought to a standstill both runs.
Also worth noting is that on the second run our rider was thrown off to the side of the scooter, which can cause a significant problem if you’re scooting on the road as you could be thrown into traffic etc.
We concede that perhaps the 800mm test may be compromised slightly as our rider had already come off, so was debatably prepared for it. However, the effects on the scooter are undeniable and we sustain that it’s unlikely many riders would be able to go over this size obstacle.
16-inch – Interestingly, looking at the 400mm test the larger wheel size meant that the front wheel never made it in contact with the ground, meaning the overall impact is far less. The rear wheel does hit the floor but by then the centre of gravity and momentum means you’re already pretty much through the hazard.
Both wheels touch the floor during the 800mm test but again the scooter is able to handle the impact without the rider losing any control. The rider maintains a good position throughout the impact showing that there is not too much energy going up through the scooter into the rider, helping them maintain control.
As our pothole test shows small wheel adult scooters do present potential dangers to riders. As micromobility grows in popularity, consumers need to be informed about which ones are safe to ride.
Small wheel scooters are in plentiful supply and often considered the standard when talking about scooter design so it's not hard to imagine how far the impacts of unsafe scooters can reach.
We welcome the inclusion of scooters in the UK's transport plans as they provide diversity in modality, and provide for the eclectic needs of the population. Different scooters types and designs can be regulated by way of a more thorough manufacturers safety standard.
We welcome the embrace of micromobility in order to build a greener and cleaner future for urban mobility, but there need to be clear guidelines to make sure it's also safe for all.