The SCOTT Lumen vs BMC Fourstroke AMP LT

Written by Isaac Boyden, on December 11, 2023

Over the last month I've had the opportunity to ride the SCOTT Lumen and the BMC Fourstroke AMP LT eMtb's side by side to really compare the two. When looking at them on paper, it’s hard to see a noticeable difference. Both bikes utilize 120mm of rear travel, they both use the same TQ motor system, and both have XC genes. For the apparent similarities however, there are a few key differences between the two bikes that stood out after a solid ride. Let's dive deeper into each bike, how they compare and which one might work better for you. 

Why a Lumen or a BMC Fourstroke - The Tech Differences 

Some readers might already be familiar with the SCOTT Lumen. The Lumen has been on the market longer than the BMC Fourstroke AMP, and it’s another 120mm rear TQ motor-equipped eMtb. The Lumen also happens to be the Fourstroke LT AMP’s main competition. These two bikes are very similar, but some riders might prefer one of them over the other. Riders looking for a more simplistic eMtb will most likely prefer the Fourstoke LT AMP. The SCOTT Lumen uses internal headset routing, an internal rear shock and an internally routed Syncros bar and stem combo. This all adds up to a very futuristic and integration-intensive bike. People who love the integrated look, and futuristic lines will like the Lumen, but it's not for everyone. The Lumen's level of integration around the cockpit and rear shock can make the bike harder for home mechanics to work on. The BMC Fourstroke AMP LT doesn't employ any of those, opting instead to keep things simple.

Another reason some riders might prefer the Fourstoke AMP LT is the suspension linkage. Unlike almost every other XC bike we carry, the Fourstroke doesn't use a "flexstay" linkage design. This means you have that beautiful feeling of true linkage-driven shock stroke and suppleness, at the small price of some added weight over a flexstay design. 

The Test Bikes 

Both of our test bikes were size medium, the SCOTT Lumen featuring a 65.5° head angle, 77.0° seat tube, and a 446mm reach. The BMC Fourstroke LT AMP has a 66.5° headtube, 77° seat tube, and a 457mm reach. Both bikes were shod with 2.4” tires, and set up for a 150lb rider. With all that info in mind, other details are listed below. 


SCOTT LUMEN 

  • TQ Motor 
  • 120mm rear travel, 130mm fork travel 
  • Alloy Syncros bar 
  • Shimano Deore four piston brakes 
  • Shimano XT 12s drivetrain 
  • Fox 34 Float Rhythm fork 
  • Forge+Bond carbon wheels 
  • Schwalbe Wicked Will 2.4 tires 

BMC FOURSTROKE LT AMP 

  • TQ Motor 
  • 120mm rear travel, 120mm fork travel 
  • Carbon Ritchey bar 
  • Shimano SLX four piston brakes 
  • Sram X0 Transmission drivetrain 
  • Rockshox SID Select+ 
  • Forge+Bond carbon wheels 
  • Maxxis Rekon Race 2.4 tires 
The Ride Review 

Even with the same amount of rear travel and nearly the same intended purpose, on the trail these bikes handle extremely differently. It seems that nowadays most bikes within a specific category perform and feel relatively similar, but I was taken aback right out of the gate by how different these two bikes actually are.

Starting strong on a technical climb definitely seemed to suit the Fourstroke AMP. With more weight over the front end and that steeper head angle, the Fourstroke AMP loves to change lines quickly, and made navigating steps and rock gardens a breeze. That being said, the Lumen also climbs exceptionally well. It should though, given that it's based on SCOTT's Spark XC frame. When compared to the BMC, the SCOTT's one full degree slacker head angle lets the front wheel wander a bit, and needs more coaxing in sharp corners.

On flatter climbs with less chunk and turns, the differences between the two bikes were less noticeable. Worth noting is that the BMC has a more supple off the top suspension feel as it doesn't use a flexstay rear end. The traditional linkage again comes into play here. 

Climbing is fun and all, but the descents and flats are where these bikes really show their differences. In flatter, rolling terrain the Fourstroke AMP has a tendency to provide a lot more feedback during the ride. When pumping or manualing through rollers and holding speed, the Fourstroke AMP seems to give you a lot more back. The Lumen was still plenty fast but wouldn't give as much back when pumping, and the bike seems to prefer to smooth out the terrain more. This sensation is due to the rear shock's tune and leverage curve.

The Lumen likes to sit much deeper into its travel than the Fourstroke AMP, smoothing out terrain but lowering the bike and eliminating some of that “pop” felt when riding the Fourstroke AMP. This changes however as things get steeper. When the going got steep, the Lumen kept better control, while the Fourstroke AMP got a little more skittish.

The Fourstroke AMP feels like a true XC bike, very fun and poppy, but that more relaxed 65.5 head angle on the Lumen does its thing and keeps the bike running straight over chunk that the Fourstroke AMP requires you to be a little more careful on. Where things get weird however, is when you experience multiple big hits in a row. The head angle on the Lumen lets you hit the hits/drops with more confidence, but bottoms out by the end (or, “stacks up”). The Fourstroke AMP doesn't feel as confident in those drops, but it doesn't bottom out as fast either. As mentioned earlier, the Fourstroke AMP doesn't sit as far into its travel as the Lumen. With a 25% sag, the Lumen sits so far into its travel that it lets you bottom out with three 8-12” drop steps in a row, where the Fourstroke AMP stays more supportive. This remained true, even with the rebound set up properly. 

Overall take

For the average home bike mechanic, the Fourstroke AMP will probably be the better choice, as it's far more simple to work on. But if that's not an issue for you and you want a more comfortable ride, the Lumen may be the better choice, as it rides smoother on most terrain. On jumps, the Fourstroke AMP feels more “whippy”, but the Lumen does the fast chunk faster. Both are light and both are stealth! One of these two bikes may suit you better than the other, so if you have questions or would like more information about them, give us a call at the shop, or chat with us here on the site.


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