We got chatting to a fella on the stand called James who explained what was going on. These bikes weren't all SingleSpeed, in fact some of them are two-speed, but you'll not spot a gear cable or derailleur anywhere on the frame. No. These bikes have AUTOMATIC gears!
We cried WITCHRAFT and set about making enquiries to the location of the nearest public ducking stool. Actually we didn't, because that would be silly. But we did feel a prickle as our interest was piqued. Before we explain how this all works we'll take a moment to set up the reasoning behind our amazement:
In London a lot of folk on single cog bikes set their gearing fairly low because there's a lot of stop-start in traffic and unless you have thighs like a power-lifter then getting a quick start on a high geared bike just isn't going to happen. The problem with low-geared bikes is that you 'spin out' quite soon after setting off. Spinning out happens when you spin your legs but don't stand any chance of actually getting up to a decent speed without looking like you're a background extra in a Benny Hill sketch.
Transversely we're based in a town a lot less crowded than Central London so we go the other way - we DO have high geared bikes because we don't have to stop very often, therefore travelling at traffic-speed is preferable to the ability to get quick starts. I personally have my SingleSpeed set to 52t on the front and 17t on the back, if I have to stop more than a few times on a journey through town my hips start feeling like someone is trying to remove them using a rusty spoon.
The two-speed SingleSpeed bike!So here's what we thought was the biggest and most exciting innovation of SPIN London, Kennedy City Bicycles have put together a bicycle that uses some clever hub-mechanics to give you a bike that's both low-geared and high-geared. When travelling below about 9mph the gearing is easy peasy; great for fast starts or bimbling through traffic, but as you breach the 9mph threshold the bike smoothly changes up to a higher gear.
We had to give this impossible-sounding system a whirl, and James was more than happy for me to hop on one of his bikes and take it for a rag around the exhibition hall. There wasn't a ton of space so I started my journey of cog-exploration at the top of a steep ramp that led into the second section of the exhibition hall. After waiting a moment for a path to clear I stepped on the pedals and gave the bike the kind of beans I usually have to use to get my high-geared SingleSpeed off the mark at traffic lights. Whoosh went I, and then just before I hit the point at which I was starting to spin-out something magical happened, the bike changed into a high gear. It wasn't a jolt like I was expecting, nor was it the sort of change one makes on a geared bike (where you have to relax your legs to make the change smooth). The change just happened, no clunks, no jolts, there was I was comfortably gaining speed at a remarkable rate. Unfortunately I was also heading with some velocity towards the far wall of the hall, so am happy to report that the brakes were also pretty effective. Although I did leave a bit of skid mark. Sorry SPIN London.
I'm not keen on the fixie style cut off bars on the bike I trialled, but if there had of been a bike with this system and drop bars I would have had to ask a friend to remove my credit card from my reach. I was that impressed. There were many pretty bikes at SPIN, but the Kennedy two-speed was the bike that I felt sad about going home without.
I do have one question though; what happens when you go up hills? Even with high gearing I can nip along at a decent enough lick, so what would happen if the gearing changed up on a climb? With any luck I'll buy one of these bikes one day and let you know...