The vast majority of bikes available in the U.K. these days come with straight handlebars, or straight riser bars like the ones that came standard on the B’twin Vitamin (I'm ingoring dropbars as they are generally on a different kind of bike). Those are fine if you are going mountain biking on the Marin trail, but not so great if you are riding on the roads. Straight bars force you to lean forward on the bike, your centre of gravity is forward of your hips and you are taking a lot of your bodyweight through your wrists.
I had read a number of things about the benefits of an upright riding position, but a great post to read is this on Copenhagen Cyclechic which explains the benefits more eloquently that I ever could. After reading this last year I adjusted the position of the bars on my Trek to allow a more upright position and felt the benefit immediately. Equally it made me realize what it was that made the standard riding position of my M-bar Brompton so nice. However both of these bikes still left my hands in a straight position, 90 degrees away from the direction of travel. So on the Nexus I decided to do things properly and get a set of swept back handlebars like you would see on nearly every bike in Holland or Denmark. There are plenty of options out there and I had been eyeing up a set of North road bars from SJScycles until I found that Decathlon sell a standard set of swept back City Bars for £8.99.
Here are the new swept bars in a side by side comparison with the existing riser bars. You can see from this how much these bars alter your grip position. What isn’t clear from the photo is how much more freedom to refine the position is available with swept bars. With straight bars you are basically stuck with one fitting position, but the swept bars mean you can alter the angle of them ( or even flip them over) on the stem clamp and in turn quite dramatically alter the riding positions available to you. This brings up yet another drawback of the majority of bicycles available in the U.K. Many now come with a threadless stem, which offers far less adjustability than a quill stem or even an adjustable quill stem like is fitted to my Trek.
I knew from my own experience and reading that the swept bars would be an improvement, but wasn’t expecting the sheer difference it made to the experience of my commute. The Nexus is a much much faster bike with swept bars fitted, so much so that I found myself cruising in 8th gear quite easily even with the new higher gearing. The bike is more comfortable and my overall feeling of subjective safety is greatly improved by having my head raised higher and upright, giving a wider view of the road and better shoulder checking. Bumps and potholes are also much less jarring, as there is less weight over the front wheel and less impact coming through the wrists.
Here is another good post on the benefits of riding upright from Sheffield Cycle Chic which catches upon the fact that many cyclists subconciously want to sit upright on their bikes. Everyone wants a cool looking bike, be it with dropbars or straight, but if they could only see themselves cycling, they might notice that their own bodies are telling them to sit upright. The problem is their bikes don't let them.
Even now the riding position on this bike is not as upright as it could be, mainly because of the stem. So there is always the option for putting a taller shorter reach stem on as well.