Lapierre's new top end ProRace SAT cross-country hardtail aims to take the sting out of the bumps using clever carbon fibre technology first seen on their Pulsium endurance road bike range. I took it on a less-than-genteel spin around the French Alps to find out just how well it works.

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The bike uses a combination of clever carbon fibre layup and frame design to allow a much larger than usual amount of vertical flex in the back and of the bike to increase comfort and traction. Lapierre calls it 'Shock Absorbing Technology' or SAT because that's what it's supposed to do. They're fond of calling a pelle a pelle over in Dijon*.

A soft-tail, but not as we know it

Lapierre-Prorace-SAT-use-106.jpg, by Damian McArthur

You might be looking at the frame and assuming that, like in other soft-tail-like designs such as the BMC Teamelite TE01 or the Trek Procaliber, the small rubber element is what gives the squidge to the back end. That's not entirely the case for the ProRace. The rubber is there to fill the gap between the two parts of the frame to ensure they don't bottom out hard and damage the fibres, as well as giving a bit of damping. The flex is given via the thin, offset seat stays and a seat post tube that's tapered in just above where it meets the bottom bracket junction.

Lapierre-Prorace-SAT-use-101.jpg, by Damian McArthur

Product Manager Serge Lopez explains: "The rubber by itself is not the heart of the system. What makes it work is the fact that we have the carbon fibre and the gap. The specific shape of the seat tube and the 27.2mm post gives more flex - the overall shape and construction allows the frame to bend and absorb some vibrations from the ground. The rubber is just there for aesthetics, to fill the gap and to avoid the fibres bottoming out against each other.”

When it comes to the overall wheel travel that this system offers, we weren't given anything specific beyond the fact that the two parts of the frame at the rubber junction move together by 5-6mm. From that, it's easy enough to extrapolate that there will be much more movement at the wheel, though exactly how much will depend on just how hard you hit things and how heavy you are. It's worth noting that each ProRace frame size has a different carbon layup to compensate for this difference in rider weight.

Lapierre-Prorace-SAT-use-102.jpg, by Damian McArthur

While the upper half of the frame is designed to maximise comfort, the 'spine' that runs from the headtube, via downtube and the bottom bracket through to the chainstays and rear axle is designed to be as stiff and efficient as possible, with broad section tubing and deep stays. There are also some other really neat features on the frame, with tidy internal cable routing ports plus a large access area underneath the bottom bracket where it's possible to place a Shimano Di2 battery if you fancy running with electronic shifting.

Specs, weight and geometry

Elsewhere, the bike is fairly conventional for a top end cross-country race bike. It's got 29" wheels and it'll take up to around 2.3" rubber, while there's 100mm of fork travel at the front. The angles are fairly conventional for a cross-country race bike too, with a 69.5º head angle, relatively slack 73º seat angle and a reach of 437mm in a Large. Chainstay length is short with a length of 428mm across all of the sizes. A 60mm bottom bracket drop helps keep things stable in the corners too.

Lapierre-Prorace-SAT-use-108.jpg, by Damian McArthur

As you'd expect from a current bike, there's Boost 148 spacing at the rear along with a 12mm through axle. The bike also has a rather neat upper chainguide that has a recessed space for a replacement quick chain link on the back side of it. It's attached using the high direct derailleur mount, and although it's possible to run a double or triple chainring setup, you might run into tyre clearance issues as Lapierre has primarily designed this bike around a single ring.

There are going to be three complete bikes in the range, with the two top models using the 'Ultimate' blend of carbon fibre that saves around 30g off the frame. A medium Ultimate frame weighed 1050g on my scales, making it reasonably competitive with frames that don't have any SAT-like system such as the Scott Scale 900 RC which comes in at a claimed 960g.

The top bike is the ProRace SAT 929. It comes with a full SRAM XX1 Eagle 12spd drivetrain, Lapierre's own brand carbon fibre wheelset, SRAM Level Ultimate brakes, a RockShox SID World Cup fork and lashings more carbon fibre finishing kit.

Lapierre-Prorace-SAT-use-100.jpg, by Damian McArthur

 The ProRace 729 steps down with a SRAM X01 Eagle drivetrain with X1 carbon cranks, a Mavic Crossmax Elite wheelset, RockShox SID RL fork, SRAM Level TL brakes and the same carbon bar, post and stem as the 929.

The most affordable bike in the range is the ProRace 629. It doesn't get the Ultimate grade of carbon fibre and it's got one gear less with a SRAM NX 11spd drivetrain with RaceFace Aeffect cranks. The fork is a RockShox Reba RL, which has the same chassis as the SID but doesn't get the more refined Charger damper. SRAM Level brakes do the stopping, while the bike rolls on Mavic CX421 rims and Formula hubs.

All the bikes use 180mm disc brake rotors up front paired to 160mm items out the back and they all get the same mismatched, tubeless ready Maxxis Ardent front and Ikon rear rubber in 2.25" and 2.2" respectively.

We're still waiting on UK pricing, but to set the scene the 729 is expected to cost around €3499-3699 and bikes will be available from late July.

How does it ride then?

If you're launching a cross-country bike, it'd make sense to ensure that the terrain is suitable and the Portes du Soleil region of the French Alps certainly provides all the climbing potential you could ever hope for. The ProRace certainly excelled there. I was riding a pre-production 729 bike, which meant that the spec wasn't quite right, with a cheaper SRAM GX Eagle 12spd drivetrain instead of the X01 Eagle of the production machines. Despite that, the Large bike I was riding was exactly 10kg, making climbing about as pleasant as it could be.

Lapierre-Prorace-SAT-use-114.jpg, by Jeremy Bernard

I really didn't notice the SAT system in action as there was no sensation of bob or movement. The bike climbs really well; there's no undue twist or power robbing softness when you stamp on the pedals. At 5'8 I sized up to a large having seen the relatively short reach figures, but it felt surprisingly spacious despite that and the short (for cross-country) 70mm stem. It's on the right side of lively too - not wanting to veer across the trail with any unintended input but certainly not sluggish. It's a good balance of being able to cut it with the pointy-elbows of the best racers while not trying to kill you if you're on a more mellow ride.

Once onto slightly rougher, looser or rooty climbing, it became apparent that the back end was definitely doing something. Despite running my usual pressures, the tyre didn't spit traction as often and there was much more grip as well as being much less jarring when putting the power over rock and roots. It didn't feel like full suspension - more like the sensation of running a really large volume rear tyre without the drag.

Lapierre-Prorace-SAT-use-112.jpg, by Damian McArthur

The only issue of riding a lightweight cross-country bike in the Alps is that you have to get back down somehow. That usually involves taking the same fireroad as you rode up or taking the more direct, rough and steep route. We did the latter. 

If you've ridden the Portes du Soleil, it's pretty famous for steep and technical downhills of the bikepark, even steeper and more technical natural trails - and braking bumps. To my absolute surprise, the ProRace did more than just cope with this terrain. Despite the steep angles and short travel, it felt surprisingly confidence-inspiring. Okay, having a fixed seatpost set pretty damn high didn't help when it got really steep (Lapierre have a 27.2mm dropper post with 80mm on travel on the way for just this reason) but the bike dealt with everything that was thrown at it and - this is the true proof of the pudding - was much, much less terrifying than I expected it to be.

Lapierre-Prorace-SAT-use-113.jpg, by Damian McArthur

That might not sound like a ringing endorsement, but it is. I rode trails I've ridden on 160mm enduro machines on some of the same trails and it was hard work then, so just making it to the bottom in one piece on the ProRace was a great achievement. Some of that has got to be down to the input of one certain ex-downhill World Champion Nico Vouilloz, who helps shape and test all of Lapierre's mountain bike range. The ProRace is certainly more than the sum of its geometry figures. 

I'm looking forward to getting hold of a ProRace to ride on some local (and much less steep) trails, but from this baptism of fire, the bike looks hugely promising as a fast, lightweight and comfortable machine for eating up the miles.

*A pelle is a spade, though apparently the French expression is 'calling a cat a cat'. Go figure...