Ellen van Dijk’s hour record-breaking Trek Speed Concept bike in detail

*UPDATE: Ellen van Dijk became the Women's Hour Record Holder on May 23, covering a total distance of 49.254km at Grenchen velodrome* 

Later today, Ellen van Dijk (Trek-Segafredo) will take to the boards in the Grenchen velodrome in Switzerland, and begin her attempt to wrest the women’s hour record title from Joss Lowden, who set the bar at 48.405km on that same track less than a year ago.

You can tune in to watch the live stream here, van Dijk will be setting off at 17:00 CEST (16:00 GMT, 11:00 ET), Monday, 23 May, 2022. But for now, let’s take a look at the bike Ellen will be riding – potentially into the history books.

Ellen van Dijk’s hour record track bike

First, the frame. Van Dijk will be riding a Trek Speed Concept TT bike (size large) which has been specially adapted for the track. The rear axle has been narrowed, horizontal adjustable dropouts put in (for tensioning the chain) and the front thru axles removed. 

Crucially, this allows van Dijk to use a frame she’s spent countless hours riding and adapting to, which will be a significant aid to her record attempt. 

The frame has been treated to a split paint job – white on one side and cobalt blue on the other. It makes for some smart looking graphics down the middle of the bike and along the top tube where the two colours meet. 

But the strongest effect of the paintjob will surely be felt by those in the stands at the velodrome – the colour of van Dijk’s bike will appear to switch every time she comes round on the near side and on the far side of the track.

In terms of the gearing, van Dijk will be running a 58x14 combination. This works out as slightly smaller (116 gear inches) than the 64x15 combination Joss Lowden used in her attempt (119 gear inches). But van Dijk will be matching this with a higher cadence, between 93 and 97 revolutions per minute, to beat the record.

To put the gearing in perspective, a 50x12 combination works out as 117 gear inches, but the smaller sprockets require the chain to bend (articulate) a little more, which increases the amount of friction experienced by the drivetrain.

Coming now to the wheels, these are Zipp Sub 9 Track shod with Pirelli Tubular 23mm tyres. Although Trek has its own in-house wheel and component brand, Bontrager, for this record attempt where the very finest margins are all important, the decision was made to go with the Zipps instead. 

They do feature a similar clock-face motif, though, to that of the Bontrager disc wheels Jens Voigt used in his own hour record attempt (successful) at the same velodrome eight years ago.

Up front, the cockpit is the Bontrager Race Space, with 40mm of spacers underneath the aero extensions. The saddle is a Bontrager Hilo XXX and van Dijk will be using a Giro Aerohead helmet.

You can read more about van Dijk's latest comments ahead of the record attempt here. Or, you can read more about the history of the hour record here.