Monday, 26 September 2016

Tech Talk: Ventum One

Radical Design Radical Result

After a year of research and development, including cutting up several top brand frames to study them and “playing with a number of interesting designs”, Ventum settled on this radical ‘Z-frame’ and took a rough prototype to a wind tunnel, where the project leap forward “The first test showed phenomenal results,” says James Seear, Ventum co founder. “The wind tunnel technician ended up re-running tests because he thought the instrumentation was playing up. In fact, our bike was so much faster than anything they’d seen.” 

The removal of the down tube addresses the most serious inconsistency between a wind tunnel and the road: the angle of the front wheel. In a tunnel the front wheel is clamped in place whereas on the road you make continuous tiny adjustments which means that the airflow from the front wheel to the down tube, the single most critical transition, is inconsistent. With only triathlon in mind, Ventum ditched the down tube altogether, removing the air transition and also that tube’s own drag. “The higher the wind speed or the larger the yaw angle the bigger the advantage our design has over frames with down tubes,” adds James. The seatstays were just two more tubes in the wind, and also a hotspot where forward rotating spokes meet rearward airflow in a tight space, so they went, too.

The Ventum frameset incorporates a fork with a standard steerer tube so that any traditional front end can be used on the bike. However, it does come with a proprietary stem and bar combo that makes for a very clean leading edge. The basebar bolts to the stem with 4 vertical bolts, and the stem attaches to the steerer in the traditional way. The fork incorporates a faring that covers the TRP V-brake and runs upward to the stem to hide the brake cabling. This also provides a place to stash the Di2 Junction box. The stem has a hole in it to pass the brake cables and Di2 E-tube wires through. The stem also has a carbon cover which serves as the steerer cap as well. Once cut, you will be hard-pressed to fit a standard stem to it. The top tube of the frame has a single hole behind the stem for derailleur and rear brake cabling, and the basebar has a port in the center trailing edge for cables/wire entry. All in all it was a fairly straight forward and clean build as far as super-bikes go. Bottom bracket is BB30 meaning it can be adapted to just about any crankset and bb system out there. 

Integrated Hydration Tank

Integrated hydration tank
The frame itself is a true monocoque, made from top-grade Toray T800, T1000 and T1200 carbon fibre but, the big innovation for Ventum, however, is the integrated hydration system—1,4L a plastic tank of liquid, refillable on the fly, sitting on the top tube and completing the aero shape. This system is elegantly simple in that the tank plugs into a hole in the frame “seat tube” and attaches with an adjustable thumbscrew mount in the front. It blends in seamlessly and does not rattle or move. The straw exits just behind the stem and has a magnet retention system that can be attached to virtually anywhere on the bike you’d like, and will hold securely. If you simply dropped it forward after drinking, it would return to the magnet on its own. That’s a lot of drag that just got saved from not having to attach a front hydration system and some kind of rear bottle cage to your bike.


Downtube: The tube link between the headtube and bottom bracket.

Toptube: The tube link between headtube and seattube

Crankset: The crankset is the component of a bicycle drivetrain that converts the reciprocating motion of the rider's legs into rotational motion used to drive the chain or belt, which in turn drives the rear wheel. It consists of one or more sprockets, also called chainrings or chainwheels attached to the cranks, arms, or crankarms to which the pedals attach. It is connected to the rider by the pedals, to the bicycle frame by the bottom bracket, and to the rear sprocket, cassette or freewheel via the chain.

Bottom Bracket: The bottom bracket on a bicycle connects the crankset (chainset) to the bicycle and allows the crankset to rotate freely. It contains a spindle that the crankset attaches to, and the bearings that allow the spindle and cranks to rotate. The chainrings and pedals attach to the cranks. The bottom bracket fits inside the bottom bracket shell, which connects the seat tube, down tube and chain stays as part of the bicycle frame.

Monocoque: Also called structural skin, is a structural system where loads are supported through an object's external skin, similar to an egg shell. The word monocoque is a French term for "single shell" or "single hull".

220 Triathlon UK 2016/10

Ride On!

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