Scott Lumen eRide 900 SL first ride review

Scott has introduced the Lumen, a ‘mid-level assist’ electric mountain bike with 130mm suspension travel front and rear. It’s heavily influenced by the Spark, borrowing its internal shock layout, and is designed to excel on both the climbs and descents.

The Lumen uses TQ’s HPR50 electric bike motor and battery system, which is claimed to be one of the lightest, quietest and most compact on the market.

With mid-level assist electric mountain bikes a burgeoning category, how does the Lumen fare?

Scott Lumen frame and suspension details

Scott says it has aimed the bike at every mountain biker and despite featuring electrical assistance, “the ride feels like a regular bike”.

The Lumen is constructed using Scott’s HMX carbon fibre and comes in at a claimed 1.95kg (without the rear shock and motor) in a size medium.

The bike delivers its 130mm travel via an internally mounted shock. There is a main pivot above the bottom bracket and a linkage that drives the shock. A flex point on the seatstay functions as an additional pivot.

Scott’s TwinLoc suspension system connects the fork and shock to a handlebar remote. There are three modes, which effectively change the bike’s geometry, suspension damping and spring curve:

• Descend (fully open)
• Traction Control (semi-open)
• Lockout (fully locked out)

Scott routes the Lumen’s cables and hydraulic hoses through the handlebar and stem, before passing through the upper headset bearing assembly.

Scott Lumen geometry

The geometry figures take clear cues from the Spark, albeit with some revisions.

The Lumen sports a 65.5-degree head tube angle, which is 0.3 degrees slacker than the Spark. This can be adjusted by 0.6 degrees in either direction using angled headset cups, resulting in three possible settings.

This is paired with a steeper 77-degree seat tube angle (over the 75.9 degrees on the Spark) and a 6mm longer reach at 446mm on a size medium.

The chainstay length has also grown by 12.5mm over the Spark to 450mm, which Scott says translates to increased stability.

Unlike some brands, Scott has opted to stick with a single chainstay length across all frame sizes because it feels its chosen measurement will suit a range of riders.

Every frame size can accept two bottle cages or one bottle cage and a range extender.

The TQ motor enables Scott to keep a standard 175mm Q-factor with a 55mm chain line, which is identical to the Spark.

Scott Lumen eRide 900 SL specification

I rode the top-spec model, the Lumen eRide 900 SL, which retails for £14,699 / $15,999 / €15,999 / AU$25,599.99.

That’s an eye-watering price and we believe this to be the most expensive mainstream mountain bike BikeRadar has ever tested.

For the asking price, no expense has been spared.

The Lumen eRide 900 SL comes shod with a Fox 34 Float Factory fork up front, with a FIT4 damper and Kashima-coated stanchions. The shock is also provided by Fox, in the form of its Nude 5T Factory EVOL.

SRAM supplies its lightweight XX1 Eagle AXS drivetrain, paired with Shimano XTR M9120 four-piston hydraulic disc brakes.

The Syncros Silverton SL2-30 CL wheelset contributes a significant amount to the cost, retailing for £4,499.90 / $4,999.99 / €4,499.90.

The wheels have a one-piece construction where the rim, spokes and hub flanges are moulded and cured together. The hub shell is bonded later in the process and provides tension to the spokes. The axle is then bonded to the flanges.

The wheels are shod with Schwalbe’s Wicked Will mountain bike tyres, in a 29x2.4in width. The rear tyre uses the Addix Speed Grip compound, whereas the front has the Addix Speed Soft – an exclusive to Scott.

The finishing kit is provided by Scott’s in-house brand, Syncros.

Syncros’ integrated Fraser bar-stem is specced and the brand’s Performance XC lock-on grips are fitted. They feature a plug, which houses the components of a tubeless repair kit either side of the bar-stem.

A Fox Transfer Factory dropper post rounds out the build, with a Syncros Tofino saddle featuring carbon rails sitting atop.

Scott Lumen ride impressions

This first ride review is based on a day and a half’s riding on a variety of trails around Massa Marittima, Italy. I plan to spend more time on familiar trails before delivering a definitive verdict.

The riding included a mixture of fire road climbs, steep singletrack and even a dedicated uphill trail, followed by a mixture of technical twisty and flowy descents.

The trails were generally quite dusty with lots of rocks ready to pierce my tyres, while the end of the first day saw us taking to the road for the last 5km or so. It rained heavily overnight before the second day, which made the trails loose and sketchy in places.

I set the rear suspension with 25 per cent sag.

Setting up the internal rear shock was not as easy as a conventionally mounted shock, but still relatively straightforward.

To set the sag, you sit on the bike and observe the sag indicator window. If you need to make an adjustment, you remove the plastic hatch at the base of the bottom bracket junction and, using an extension piece for a shock pump hose, you can then make adjustments to the air pressure.

Climbing performance

The Lumen is an excellent climber and the TQ system comes into its own in this regard.

Two of the three rides started with an uphill-specific section called the ‘Spaghetti Trail’, a singletrack climb peppered with tight rooty hairpins.

The motor assistance is loads of fun in this type of terrain, giving you the extra power to get around corners while you focus on negotiating the roots.

The 65.5-degree head tube and steep 77-degree seat tube angles are well-judged, enabling you to pedal the bike with vigour when seated. The angled headset cups were set in the middle setting of 65.5 degrees, making for measured and precise steering.

I rode a size large but, at 5ft 11in, I could have ridden an XL. The reach was a little on the short side, but not overly so.

The Lumen’s still got a cross-country flavour. The stem is slightly longer than typical trail mountain bikes at 70mm and the fact Scott has stuck with the TwinLoc system also shouts out its cross-country roots.

I’m not convinced TwinLoc is needed on the Lumen.

There’s no doubt it’s a worthwhile addition for the Spark with its cross-country racing agenda, but with the increased travel of the Lumen and the fact it’s not going to be raced, I question its inclusion.

I was happy climbing in the fully open Descent mode and couldn’t detect any bob. I only really used the Traction Control mode to see what difference it would make.

I certainly never felt the need to fully lock the suspension, other than on a 5km road section towards the end of one ride.

Descending performance

The Lumen proved a sure-footed descender, with the 130mm travel soaking up the bigger hits and proving a perfect match for the flowy Massa Marittima trails.

Scott has made a shrewd move upping the travel to 130mm over the 120mm found on the Spark.

This allows for extra rowdiness and, let’s face it, cross-country racers are unlikely to whip a leg over a Lumen in a race, so you might as well benefit from the additional travel.

On my three rides in Tuscany, I never used the full available travel, but there are some home trails where it would come in handy.

It’s a playful bike too and ready for pretty much anything you can throw at it. It was particularly poised on more flowy trails and appeared happy to open the taps.

The 65.5-degree head angle instilled confidence when descending, although a slightly longer reach and shorter stem would be beneficial given the Lumen is more focused on having fun on the trails than climbing.

TQ’s HPR50 – the new kid on the block

I found the TQ HPR50 system excellent and with some further refinement, it's a potential game-changer for the electric mountain bike market.

You can hear some motor whirring when you’re really pushing it, but otherwise it offers a very natural ride feel.

I rode the bike in a range of scenarios without assistance.

You can still tell you’re riding a bike that’s being held back a little by the weight of the motor and battery, but this is by far and away the nearest electric equivalent to a conventional mountain bike.

In the second part of the ride on the first day, Scott mounted TQ’s range extender to the bike. The additional 950g weight wasn’t really noticeable.

Before the ride, I installed and paired the TQ app with my bike.

Scott sets the response rate of the TQ motor to zero per cent as stock.

Prior to the second ride, I paired the Lumen with the TQ app and upped the pedal response rate to around 30 per cent on each setting. This offered a more natural ride feel, particularly in the ‘Mid’ and ‘High’ settings, where you’d expect the motor to respond more rapidly.

I finished my first 20km ride with 700m of elevation with 38 per cent battery life remaining.

Using a range extender, the second 20km ride with a similar elevation saw me finish at 60 per cent. The final ride, of 17km with 500m of elevation, saw me drop to 88 per cent, also using the range extender.

TQ says you may notice when the motor changes between batteries because it requires “a very brief cut in power”.

Product manager Daniel Theil explains there isn’t a way around this because the batteries operate at different voltages, which “makes it impossible to run both batteries parallel”, although he says TQ has “worked hard to speed up this handshake and in many cases, the rider will not notice it at all”.

I felt the motor cut out briefly while riding up the Spaghetti trail on the third ride, but I couldn’t detect it changing between batteries on the second ride despite watching the battery life drop from 101 per cent to 100 per cent, when I was riding up a mellower climb.

Scott Lumen additional build details

The rest of the build generally impresses, as you would expect for the mind-blowing asking price.

SRAM’s XX1 Eagle AXS drivetrain didn’t miss a beat, my only gripe being the shifter paddle, which I don’t find as intuitive to use as the equivalent mechanical lever.

Rather than pairing the SRAM drivetrain with matching brakes, Scott specs Shimano XTR M9120 brakes. They performed excellently, although they offered a more binary feel than SRAM’s G2 or Code equivalent.

SRAM shifters and Shimano brakes typically don’t sit nicely together on the handlebars, but Scott has specced a custom-made adaptor that pairs them in a neat package.

The choice to spec 180mm disc brake rotors front and rear is fitting for the trails the bike is realistically going to be taken on.

The Syncros Silverton wheels do a lot of the heavy lifting with the ride quality.

The wheels are a predominantly one-piece design, with the hub shell bonded to the structure. They were blisteringly responsive on descents, accelerated quickly and crucially didn’t offer an uncompromisingly stiff ride feel.

Syncros product manager Julien Chauveau, says the wheels are covered by a two-year warranty and three-year ‘Crash Replacement Program’.

If you damage a wheel in the first year of ownership, Syncros will offer a 50 per cent discount off the retail price for a new purchase, then 30 per cent in the second year and 20 per cent in the final year.

This is not as extensive as other brands' carbon wheel warranties, such as Santa Cruz, which offers a no-quibble repair or replacement lifetime warranty for its Reserve wheel.

Chauveau noted some breakages can be repaired by carbon fibre specialist companies Scott partners with. I was aware of two breakages in the group over the three rides.

The Schwalbe Wicked Will tyres were an excellent choice and stuck like glue to the trails.

A frustrating number of brands opt for XC-oriented tyres on this kind of bike, and that can really affect the ride quality, especially when you consider the motor and battery adding extra weight and often speed.

The Syncros Fraser integrated bar-stem hides all of the cables and lends the bike a clean aesthetic.

This will make servicing the headset more onerous, but such integration is now common on high-end bikes.

Scott says it has engineered some flex into the bars. I found them on the stiffer side, but this could also have been the fault of the Syncros Performance XC grips, which I found uncomfortable.

The stem bolts that secure the bar-stem to the steerer tube are concealed by a plastic cover. The positioning of the bolt heads makes for a tight angle if you need to make an adjustment, so take care when using a hex key to avoid rounding the heads.

The Syncros Tofino saddle was unremarkable, although Fox’s Transfer dropper post was brilliant with an effortlessly smooth action from the TwinLoc lever.

Finally, it’s impossible not to comment on the finish of the Lumen SL – the Candy Red flakes sparkle in the sun, oozing quality.

Scott Lumen eRide 900 SL bottom line

Scott’s first mid-level assist electric mountain bike is a hit in many regards.

The 130mm travel feels appropriate and early impressions suggest the Lumen balances being a competent climber and capable on the descents.

However, there’s no getting around the price for this top model. £14,699 is an absurd amount of cash and this particular build will be out of most riders' reach. The lower 900 and 910 models use the same frame and TQ system, and would likely offer similarly competent ride qualities.

That said, I really enjoyed my experience on the Lumen eRide 900 SL and I can’t wait to see how it behaves on familiar UK trails.