We review the Lapierre Aerostorm Ironman triathlon bike

Lapierre Aerostorm
£3,099.99 (frame, fork, seatpost, stem)
hotlines-uk.com, cycles-lapierre.fr

This unique looking, pro-team proven French clock hunter is definitely going to turn heads in transition, and it’s a proper straight-line super-fast TGV on the tarmac too. It’s definitely designed for confident bike handlers though, and is not one for beginners.

Rearward balance and a light front end can take a bit of getting used to – but it’s worth it as this is a very fast bike

The French take time trialling, or “contre le montre” racing, almost as seriously as the Brits and they’ve never been shy of producing distinctive designs to stop the minute hand ticking earlier than you expect. The integrated stem of the Aerostorm looks more like a stylised Gothic eagle gargoyle from a Tim Burton film set than a piece of a bike, and it comes in a choice of three lengths for custom tuning. As radical as the front end looks it’s nothing compared to the back end. The seat tube slopes steeply back from the PressFit bottom bracket to join the long chunky cut geometric top tube. A wheelhugger cut-out allows the extended blunt back Kammtail section to sit right back over the rear wheel.

A forked-based vertical seat mast slots over the triangular block at the back with two slots allowing upwards adjustment if you loosen the bolts. Surprisingly narrow rectangular chainstays start almost straight then kick out Scott Plasma style to meet the wheel. Short teardrop section seatstays curve down from a flying bridge on the seat tube to end the circuit.

While the rear dropouts are conventional non-adjustable vertical slots, the very steeply forward raked integrated forks also get horizontal dropouts. These allow you to change the position of the front wheel by as much as 2cm with screw adjusters for accurate alignment.

Lapierre have taken a lot of effort over integrating the Di2 hardware into the frame as cleanly as possible. The battery sits under a flush cover in the geometrically shaped down tube, with the control wires only popping out at the appropriate parts of the frame. To keep the front end of the bike as aero as possible, the Di2 wiring feeds through a window on the underside of the stem into a corresponding window in the frame. Even with thin wires rather than stiff cables, that makes for a very restricted steering lock and with the long stem and low bars it’s all too easy to jackknife the bike and fall over at slow speeds which could be expensive as well as embarrassing.

The other clearance issue to note is between the offside crank and the cable adjuster wheel. The CNC brakes used on our test build actually clipped the crank if they weren’t in the right position, so spec and check them carefully before clanking off down the road in a shower of swarf. The front brake is a totally conventional mount though, so there are no worries there apart from the fact its placement is not particularly aerodynamic.

The Aerostorm comes as a frame, fork and seatpost kit for £3,099 and build up from there is up to you. Seeing how seamlessly it integrates into the frame, not going digital would be a crying shame though. The aero bar section
of the Pro Missile Evo bars fit very neatly with the stem, and the super light Easton wheels enliven acceleration and climbing performance.

As soon as you are on board the Aerostorm it’s clear the ride is as radical as the looks. The stem is flush with the top tube and puts the default cockpit level down low – although you could bring it up with taller extensions and pads. The restricted steering lock isn’t the only handling feature either. The adjustable front wheel position gives the bike slightly peculiar steering characteristics. It’s a bit Jekyll and Hyde – agile at the front and then at times it steers and tracks like a truck, with an unnerving ability to pick up speed when travelling in a straight line.

Because the rider weight is so far back over the rear wheel, the pivoting balance of the bike is much further back, which throws the weight distribution completely. The big front-end frame tubes also make it very quick and accurate to react to any steering inputs. Add very long chainstays that create a super stable ‘kite tail’ effect and, while it’s phenomenally composed in a straight line, it’s definitely a bike you’ll need to learn how to use when it comes to the twisty stuff.

Once you have got used to the idiosyncratic handling though this is a seriously fast bike: unerringly fast in a straight line and with better power transfer than the skinny chainstays would suggest. It’ll take its muscle medicine standing up or sitting down. Even with relatively shallow, light wheels it held its speed well, and switching to deep sections for part of the test really upped its velocity sustaining capabilities. While they make sure steering and shoulder power all have the maximum effect when you’re pushing hard, mainframe stiffness doesn’t leave much road surface information to the imagination. That means you will need to be prepared to some abuse on less-than-perfect Tarmac.

+ Very stiff mainframe means you can exploit full body power
+ The neatest Shimano Di2 integration we’ve seen on an aero bike

– Handling steering lock takes some getting used to
– Not the comfiest of machines if the road surface is below par