The Sonnet Track MKII is an odd bike — despite being called the Track MKII, it has routing for both front and rear brakes and the option to spec 28mm tyres, which are both very non-velodrome like characteristics.
On the other hand, the bike has no provisions to mount bottle cages and its lo-pro-ish silhouette forces you into a constant, track-friendly aero tuck.
With all of these contradictions in design, it’s easy to dismiss this bike as merely a £2,500 fixie with an identity crisis, but as soon as I got to spend some time on the open road, I quickly forgot any of my preconceptions about this unique bike.
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The potent mix of terror and fun is what makes riding fast on a fixed gear bike so addictive, and the Sonnet Track MKII is a bike that wants to go damn fast.

The low front end forces you into a powerful and aero position that — when matched with the stock 44x17t gearing — encourages rowdy sprint-heavy efforts up every lump you encounter.

The Columbus SL tubing used on the frame has also been carefully selected to maximise power transfer while maintaining a degree of comfort.
The bi-oval downtube is oriented to resist fore and aft flex at the headtube and side to side movement around the bottom bracket. Matched with the tight rear triangle and hefty oval chainstays, the bike proved to be a snappy ride that behaved well, even when mashing up dreadful hills out of the saddle in what is unavoidably far too hard a gear.

Having been relegated to use on all but the cheapest bikes in the mainstream market, the positively retrograde 1” threaded steerer and quill stem used on the Sonnet will jar with some.
While I will admit to initially having my misgivings about this spec choice when I first saw Sonnet launch back in January, I would be lying if I said I didn’t fall in love with how cleanly the quill stem ‘flowed’ into the frame's skinny tubing as soon as I unboxed the Track MKII.

And as far as quill stems go, they don’t get any nicer than the Nitto Craft that was fitted to my test bike.
Constructed from fillet brazed steel, when matched with Nitto’s own M106 bars, this cockpit affords the front end of the bike a welcome level of sproingy-compliance that resisted any unpleasant levels of twist when pulling on the bars.
While a fixed drivetrain will inevitably limit your top speed, the bike was also well mannered on the descents.
I believe this is in part due to the bike's slightly higher than average bottom bracket — bearing in mind that on a fixed gear bike you don’t have the luxury of choosing the orientation of your cranks as you lean through a corner, anything that keeps your pedals a little further from the ground is very welcome.
The low rake fork, steep head angle and short wheelbase mean that the Track MKII isn’t the most stable ride in the world and it was reluctant to ride easily with no hands, but I found this makes the bike feel more quick handling rather than nervous and twitchy.

The rest of the build is a selection of top shelf track components that would make any circa 2006 fixie-ista blush — everything from the Tange headset and bottom bracket to the DID Racing Pro Keirin NJS chain and Nitto S65 Crystal seatpost is bound to set the heart of any Fixed Gear Gallery visitor aflutter.


The wheels are also a highlight — supplied by the legendary wheelbuilder, Harry Rowland, the Mavic Open Pro rims are laced to Miche Primato hubs and are a classic combo which feel excellent under power while maintaining a degree of compliance when things get bumpy.
While I may have enjoyed indulging in the #fixiefamous lifestyle for a few weeks, I’m a mere mortal and have never felt the urge to ride brakeless, so the powerful and consistent braking supplied by Campagnolo’s Potenza brakes was readily welcomed by this wuss.
If you're looking for extra reassurance, the bike is also supplied with a White Industries freewheel, which will provide you with the magic that is coasting.
This high-end build weighs in at 9.12kg with Ultegra pedals fitted.

With 25mm Gatorskin tyres fitted, the clearance around the front brake is quite tight and although I took the Track MKII on a few naughty gravel adventures without mishap, I found that it had a tendency to clog up a little around the crown on very muddy roads.
This will of course only be an issue for those that choose to ride a £2,500 fixie on roads as poor as those around BikeRadar’s native Bristol, but is worth bearing in mind.
So who exactly is the Sonnet Track MKII for?

Fixed gear bikes are popular as both training tools for serious roadies and as accessories for hipster millenials, and I think the Sonnet Track MKII is the perfect bike for those that fall into both of these categories.

It is a perfect balance of beautiful, niche craftsmanship matched with great road handling characteristics that will appeal to those that absolutely must have something different but still want to enjoy long, singlespeed days in the saddle.
And at £1,250 for the frameset and approximately £2,500 for the build as pictured, you’ll likely be one of few on the road with one.
(US/AU pricing unavailable at the time of writing, but Sonnet will ship internationally)