While 29″ wheels are a staple amongst conventional mountain bikers, they’re still something of a rarity on E-MTBs. That was always the case until now, as Lapierre steps grandiosely into the exclusive club of potent 29er E-MTBs with their Lapierre Overvolt AMi 29 Shimano – a bike with more to offer than just big hoops.

Lapierre Overvolt AMi
Lapierre Overvolt AMi 29 Shimano – Travel: 140/140 mm – Price: tba Sept/Oct 2017

Lapierre’s R&D department is now headed up by 10x Downhill World Champion Nicolas Vouilloz, so it doesn’t come as a surprise to see that the brand’s latest E-MTBs have borrowed a lot of cues from their conventional, non-motorised models. This latest model, according to Lapierre, was all about integrating the battery without impacting on those familiar, respected Overvolt genes. The result is the Overvolt AMi Shimano, a brand new development with some really eye-catching features. It’s being launched in two versions: one with 160 mm travel and 27.5+ wheels, and the second iteration with 140 mm of travel and 29″ wheels. The big-wheeled version is the one we’ve been taking a closer look at.

The Lapierre Overvolt AMi 29 Shimano in detail

Those 29″ wheels are the most visible trait on the new Overvolt AMi 29 Shimano, which is a marked step away from convention with E-MTBs and it’s fair to say that the market hasn’t seen many long-travel 29er E-MTBs thus far. Yet the advantages are manifest: they’re better at rolling over burliness on the trail and they keep their speed more than smaller wheels – two factors that E-MTBers should don’t underestimate. With grippy tires measuring between 2.4″ and 2.6″, the level of grip is likely to rival wider 2.8″ rubber on 27.5″ wheels.

Lapierre Overvolt AMi
Still not commonplace on E-MTBs: 29″ wheels aren’t just the preserve of hardtails, they’re also well capable of taking on technical terrain.

The second feature of note is Lapierre’s approach to integrating the 500 Wh battery with so-called Snake Power Technology. Unlike regular batteries, this one has split its cells between six smaller blocks, which are loosely linked. This flexible design lent the engineered the freedom to design a stiffer downtube with an opening that’s 70% smaller than a conventional integrated Shimano battery. The battery is also 20% smaller than Shimano’s solution–despite having the same capacity. It can also be charged on or off the bike.

Lapierre Overvolt AMi
A barely-there flourish for the cover…
Lapierre Overvolt AMi
but it’s enough to take out the compact battery.
Lapierre Overvolt AMi
Not one for rapid, brutal movements: taking out the battery requires a gentle touch that takes some practice. Once nailed, it can be done in a matter of seconds.
Lapierre Overvolt AMi

The cover is fixed with the turn of a key on the opposite side.
Lapierre Overvolt AMi
The Snake Power battery is smaller and longer than a one-piece design, but it’s still designed to fit inside the majority of backpacks.

Unlike the well-known OST+ rear end design, Lapierre have opted for a new 4-pivot design on the Overvolt AMi 29 Shimano with a low positioning for the rear shock, which both drops the centre of gravity and reduces the likelihood of braking influence. Their integrated battery design also conjures up space for a bottle cage mount. Note that the specs and graphics are not finalized yet, our test bike was still in a prototype stage.

Lapierre Overvolt AMi
The rear shock has a super low position to aid a lower centre of gravity.
Lapierre Overvolt AMi
A sleek button on the top tube switches the bike on and off.
Lapierre Overvolt AMi
The charging socket is overly exposed on the downtube and we’d have preferred to see it elsewhere.

The geometry of the Lapierre Overvolt AMi 29 Shimano

The Overvolt AMi 29 Shimano also borrows significant geometry cues from Lapierre’s stable of conventional mountain bikes, and that compact Shimano motor allowed the developers to retain fairly short, snappy 460 mm chainstays despite the big 29″ wheels. The rest of the geometry is fairly reflective of contemporary 29er trail bike fashion, with a satisfyingly (but not excessively) slack 67° head angle, and a fairly steep 75.5° seat angle.

Size S M L XL
Seat tube 400 mm 430 mm 460 mm 500 mm
Head tube 580 mm 610 mm 635 mm 660 mm
Head angle 66 ° 66 ° 66 ° 66 °
Seat angle 73 ° 73 ° 73 ° 73 °
Chainstays 460/470 mm 460/470 mm 460/470 mm 460/470 mm
BB Drop -5 mm -5 mm -5 mm -5 mm
Reach 395 mm 422 mm 444 mm 466 mm
Stack 606 mm 616 mm 625 mm 634 mm

The Lapierre Overvolt AMi 29 Shimano on the climbs

Over at the French ski resort of Valberg we had ample time to test the Lapierre Overvolt AM 729i Shimano on the diverse trails. For a 183 cm rider, the size L frame was an ideal fit, lending a super balanced riding position. As we pedalled off onto a gravel track to begin, the 29″ wheels demonstrated their advantages for the first time, as they keep speed much longer than smaller 27.5″ wheels. But as the long-travel Overvolt AMi is clearly capable of way more than just gravel, we quickly dipped off onto some narrow singletrack.

Lapierre Overvolt AMi
A veritable mountain goat: the Overvolt AMi 29 Shimano has a winning geometry setup and great roll-over characteristics.

The steep seat angle means you’ve got ample pressure over the front wheel so you can keep it planted on steep gradients even with those fairly short chainstays. When the trails get more techy, the 29″ wheels wield their charm and roll good-naturedly over small drops, roots and rocks. This lends the Overvolt AMi 29 Shimano real skills on the climbs, and the bike clearly feels at home as you thread your way up tricky ascents. The Shimano motor displays that now familiar natural ride sensation, which is an asset for the Overvolt.

The Lapierre Overvolt AMi 29 Shimano going downhill

The trail we take starts with a drop over a mellow Alpine field, before weaving into some burly rock gardens and nasty steep parts. Last year it was part of the Enduro World Series, so it’s suitable gnarly although it doesn’t faze the Overvolt AMi 29. The big wheels do their thing on the descent, and it holds its speed really well–although the need to pedal is more absent than usual. The moderate head angle and 2.6″ tires on the AMi give it a playful and lively side, but it needs some muscle around tight corners (especially compared to an 27.5″ bike). As we hit a super burly section there’s a moment of longing for more travel and a slacker head angle, but we reason that those elements would have then taken their toll on the climbs.

Lapierre Overvolt AMi

Our test bikes were still a pre-production model and the rear shock hasn’t been finalised in terms of tuning for the rear end. Yet even with the base tune, we found that the Overvolt AMi 29’s suspension gave little rise for complaint, with really decent, relatively high end progression and even with 30% sag there was no harsh bottoming out episodes. We’d have like a bit more mid-stroke support, but overall the new Lapierre rear design grants a hell of a lot of traction and great sensitivity.

Lapierre Overvolt AMi
The Overvolt AMi 29 lies plush to the trail and rides with great stability and predictability at high speeds.

The Overvolt AM 729i is firmly in the midrange of the new line-up and this is reflected in its highly practical, well-considered spec: the FOX 34 forks work well, but we welcome the decision to kit the coming series bike out with a stiffer FOX 36. The Schwalbe Nobby Nic tires in a 2.6″ width are a step forward from earlier iterations with the now thicker Apex carcass. However, a bike of this calibre really deserves even grippier and more stable tires to keep rubberside down. The SRAM Guide RE brakes are a good anchor for the Overvolt, and the wisely chosen 200 mm front and rear rotors have great modulation and consistent braking power. However, the specifications and cosmetics are not 100% final yet and will be announced later this year.

Lapierre Overvolt AMi
140 mm suspension doesn’t sound like much, but team it with those 29er wheels and you’ll be singing.
Lapierre Overvolt AMi
The Schwalbe 2.6″ Nobby Nic tires are definitely boosted by their now more stable Apex carcass but they quickly reach their limits.

Our thoughts

Last year’s launch of their Overvolt AM Carbon ushered in a new radical model for an E-MTB, but Lapierre weren’t content with just one great bike so the French brand have ploughed on to develop not only the brand’s first Shimano-equipped E-MTB but also one of the most potent 29er E-MTBs on the market in the Overvolt AMi 29. Adding serious fuel to the wheelsize debate, these big hoops win our full approval on the trails so if you’re looking for an E-MTB that’s capable of hurling over technical terrain then the Lapierre Overvolt AMi 29 Shimano is certainly worth a closer look.

For more info head to the Lapierre Website

Words: Moritz Dittmar Photos: Moritz Dittmar, Matt Wragg