Single-pivot frame and super-wide tyres are the key to this go-fast machine

By Tom Marvin

Published: Wednesday, 25 September 2024 at 14:00 PM


Lauf has taken its bike range to the next level with the release of the Elja, the brand’s first mountain bike, designed to tackle the worlds of XCO and downcountry.

Lauf believes the secret sauce for going fast is the humble single pivot. There are no fancy flex stays or complex linkage designs – simply a true two-bar single pivot.

This is contrary to much of the industry, where multi-link designs dominate, giving engineers more control over leverage ratios on shocks.

Lauf joins a small crew of single-pivot, 2-bar devotees, most notably Orange and Starling. However, whilst both brands have built shorter travel bikes – the Segment or Sub-5 of old, or Mini Murmur, neither has delved into the world of carbon XC-race-ready rigs.

The Elja’s other sprinkling of magic is in the tyres. Should you wish, you can squeeze 3-inch rubber into the rear triangle. Stock bikes roll on 2.6in tyres.

However, getting broad rubber for an XC bike is tough. So Lauf, being Lauf, had some custom-made.

Elja means something akin to having a gritty nature, much like the Seigla name of Lauf’s gravel bike. – Tom Marvin / OurMedia

As you’d expect from the brand that brought us the True Grit and Seigla gravel bikes, and the Uthald road bike – as well as unique linkage forks for MTB and gravel – the Elja is carbon, and introduces specific areas of flex to ensure tip-top performance.

In keeping with current trends, there’s 120mm of travel at the rear, with the XC builds coming with a 120mm RockShox SID fork and the downcountry builds with a 130mm RockShox Pike fork.

Why is the Lauf Elja a single pivot?

Lauf Elja XC and downcountry full suspension mountain bike
LSP – Lauf Single Pivot. It’s in the name. – Tom Marvin / OurMedia

Lauf’s engineers spent a lot of time in the launch presentation talking about suspension linkage systems, their differences and their similarities.

Every brand will have a different take, but Lauf believes most leverage curves on XC bikes, created by differing linkage systems, are pretty similar – and don’t offer a huge amount of progression.

It also reckons the most important aspect of suspension performance comes down to the rear wheel’s centre of rotation – the real, or effective, pivot point.

With the development and tunability of shocks, the rest of the fine detailing of how the suspension feels can be done via the shock’s damper and air spring.

Lauf looked at the centre of rotation on a range of XC bikes and found that the bulk, whether single-pivot flex-stay, or multi-link designs, tended to average out just above and just in front of the chainring.

As such, why not just make a single pivot, with a pivot roughly in that location, and work with RockShox to fine-tune the feel and give the required progression via the spring?

Where is Lauf’s pivot located on the Elja?

Lauf Elja XC and downcountry full suspension mountain bike
A chunky, asymmetric swingarm ensures stiffness where it’s needed. – Tom Marvin / OurMedia

Lauf did, however, feel a slightly higher and further forward pivot location was preferable.

This, it says, increases anti-squat – the force that resists pedal bob, reduces brake jack – the stiffening of suspension under braking – and gives a slightly improved initial arc of the wheel under impact.

The cost is slightly more chain growth, which theoretically can mean a little more feedback through the pedals on bigger hits.

The challenges of single pivots

Lauf Elja XC and downcountry full suspension mountain bike
There are no additional pivots on this single swingarm. – Tom Marvin / OurMedia

One of the main issues with a two-bar single pivot is increased wear on the shock. The rear swingarm flexes and puts lateral forces through the shock, leading to damage to the shock’s shaft.

Lauf is well known for flex – whether it’s the glass-fibre struts in its Grit gravel fork, or the thinned top tube on the Seigla gravel bike, which adds compliance. The Elja has’t dodged the engineers’ love for a bit of bend.

The shock is driven by two slim arms emerging from the swingarm that flex, giving the SIDLuxe shock, held in by titanium hardwear, protection from the lateral forces that might otherwise cause premature wear.

Lauf Elja XC and downcountry full suspension mountain bike
The rear end pivots around a SRAM DUB bottom bracket. – Tom Marvin / OurMedia

The lower portion of the swingarm, from the pivot to the bridge between the two asymmetrically built halves of the swingarm in front of the wheel, is built super-stiff. It pivots around a SRAM DUB bottom bracket, this being the ‘ideal’ solution to a large-diameter, wide-braced pivot (it’s also handily cheap and easy to replace).

The design – location of the pivot, sturdy ‘bracing-box’ swingarm and flexible shock ‘flex-arms’ – is called LSP (Lauf Single Pivot).

Final touches

Lauf Elja XC and downcountry full suspension mountain bike
It’s pretty snug for a pair of bottles, but they will fit. – Tom Marvin / OurMedia

The frame’s main story is clearly the suspension layout, however there are a few interesting touches along the way.

The frame is built from a standard-modulus carbon fibre. Lauf said a higher-modulus carbon could have resulted in a lighter bike. However, the frame is already within a claimed 100g of competitor frames, and higher-modulus carbon is less impact-resistant – something Lauf didn’t want to compromise on.

Lauf gives a claimed frame weight of 1,960g for a Medium, of which around 130g is paint.

There’s a pair of bottle cages within the frame, although the compact nature of the available space means side-entry and small or Fidlock bottles are required.

There’s a third pair of bosses under the down tube, too.

Lauf Elja XC and downcountry full suspension mountain bike
Only the brake hose is fed through the frame, in fully guided tubes. – Tom Marvin / OurMedia

The rear brake hose is fully routed, from the side of the head tube all the way to its exit point on the swingarm – no headset cable routing here.

Next to the hose entry is a spare hole, should you wish to run a cable dropper, however every model on sale comes with a RockShox Reverb AXS post – a wireless dropper. As such, there are no internal cable guides, although you could run a loose cable if required.

There’s also no provision for a rear-shock lockout.

Most models have RockShox Flight Attendant shocks fitted, while those on more entry-level models will have to reach for a two-position lockout lever on the shock.

Lauf Elja XC and downcountry full suspension mountain bike
Tom Marvin / OurMedia

In another nod to fuss-free living, the bike is wireless-drivetrain only.

Finally, Lauf specs FSA-built damped headset Honey bearings top and bottom. My experience of these on my gravel bike is that they help calm steering a touch, filter out twisting chatter through the bar, and help slow the bar from flopping from side to side during maintenance.

Fatter is faster

Lauf Elja XC and downcountry full suspension mountain bike
If nobody makes a suitable tyre, get one made! – Tom Marvin / OurMedia

When Lauf launched the True Grit gravel bike, the 45c tyre clearance was seen as extreme.

When the brand unveiled the Seigla, the thought of running 2in mountain bike tyres was deemed even more out there.

The Elja is an XC race bike, specced with 2.6in tyres. It will easily fit 2.8in tyres and has space for 3in rubber.

Lauf firmly believes wider tyres are faster.

There aren’t many XC-race ready tyres available at 2.6in, so Lauf went to Goodyear, which has opened a 2.6in mould of its Peak XC tyre.

Lauf Elja XC and downcountry full suspension mountain bike
There’s plenty of clearance in the fork for wide rubber. – Tom Marvin / OurMedia

While thin tyres feel fast, thanks to increased vibration and sketchy handling, Lauf claims that in reality the additional grip and supple sidewalls offered by wide tyres at low pressures makes them faster.

This seems to hold true (at least to some extent), given the road WorldTour’s shift to wider rubber, and pretty much all of the best gravel bikes coming with 45-50c+ tyre clearances, even on their race bikes in 2024.

How this will translate to MTBs is yet to be seen.

Lauf Elja geometry

Lauf Elja XC and downcountry full suspension mountain bike
The Lauf Elja has 120mm of travel at the rear, with 120 or 130mm forks plugged in up-front. – Tom Marvin / OurMedia

While Lauf has pushed the boundary in geometry terms with the Seigla and Uthald, the Elja is modern without being extreme.

There will be XC and trail (or downcountry) versions of the bike, with 120mm or 130mm forks, so the geometry will differ slightly depending on fork travel.

The 130mm-fork bike will have a slightly slacker head and seat angle, higher bottom bracket and slightly reduced reach, because both versions of the bike share the same frame.

Below is a geometry chart for an Elja with a 120mm RockShox SID fork and 2.6in Goodyear tyres.

Four sizes are on offer, for rider heights from 156cm to 200cm.

Lauf Elja XC and downcountry full suspension mountain bike
Yep, tons of room in there. – Tom Marvin / OurMedia

Reach figures range from 420mm to 507mm, with the Large sitting at a lengthy 480mm. The 66-degree head angle is slack, but in line with most fresh XC bikes out there, while wheelbases range from 1,149mm to 1,249mm.

Seat angles range from 77.5 degrees in the Small through to 75.7 degrees for the X-Large – seat angles usually steepen with larger-sized bikes.

Chainstay lengths are consistent across the sizes at 435mm.

SMLXL
Seat tube angle (degrees)77.576.876.275.7
Head tube angle (degrees)66666666
Chainstay (mm)435435435435
Seat tube (mm)406443453463
Head tube (mm)95106117127
Bottom bracket drop (mm)40404040
Wheelbase (mm)1149118312181249
Standover (mm)724747756765
Stack (mm)595605615625
Reach (mm)420450480507
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