I don't know how you all are, but when I see a new technology or something sophisticated in the transmission system or more intricate levers in the suspension, I am amazed, pleasantly surprised, and I wonder how it works, what it adds, how it rides, what the maintenance of this thing is like? Another chain? Oh dear, it's also exposed, another plate to remove and clean...

RMU launches the Nighttrain model, a bike clearly aimed at the aggressive gravity/enduro segment, built around the new generation of Orion suspension. The platform promises high sensitivity on small bumps, but also consistent support when the pace increases.

“The system has been completely reconfigured to provide support and suspension control similar to what I would design for a World Cup DH race bike… It’s supple on the small bumps… when you get into berms… there’s support… and on bigger hits, that support gives way to big bump compliance. The harder you push it, the more it rewards you.”
— Dave Weagle

Suspensions designed by Dave Weagle, briefly you can find only the initials DW in descriptions, we also find them implemented at Esker: https://eskercycles.com/pages/orionsuspensiondynamics

Esker bike in nature

Esker Orion Suspension Dynamics SystemEsker Orion Suspension Dynamics System 2

But also at Pivot: https://www.pivotcycles.com/en-us/bikes/phoenix

phoenix sram hero2

Pivot Phoenix transmission zoom six bar dw link

Pivot Phoenix DW transmission dual chain,

Atherton also has the DW6 system: https://www.athertonbikes.com/bike/a150-enduro.html

Atherton enduro A.150 with DW6

For enthusiasts: http://www.dw-link.com/home.html, http://www.dw-link.com/physics.html

Frame, kinematics, and technologies

Nighttrain is not just a frame with a premium shock, but a fairly complex technological package, centered around a few key ideas:

https://rmumtnculture.com/products/nighttrain

Nighttrain Orion design

Orion Dynamics – 6-bar flexstay

The platform is developed by Dave Weagle and implemented here as:

  • 6-bar flexstay design

  • two short links that control lateral stiffness and braking forces

  • kinematics optimized for 1x transmissions with a wide range

The declared result:

  • pedaling efficiency without pedal feedback

  • consistent traction on varied terrain

  • stable behavior both uphill and on technical descents

RMU mentions that this generation of Orion is completely reconfigured compared to previous versions.

Mid-pivot + dual idler

Nighttrain uses a mid-pivot architecture, but without the typical compromises thanks to the dual idler system:

  • chain positioning similar to a high-pivot

but without the efficiency losses of a single idler

Orion dual idler transmission

Advantages:

  • significant reduction in pedal feedback

  • minimal influence of the derailleur clutch on the suspension

  • efficient power transfer through a dual chain system

Interesting implementation details:

  • large primary chainring, with an odd number of teeth

  • chain with an even number of links → reduced wear

  • large secondary chainring → increased efficiency

Axle path and dynamic behavior

The mid-pivot configuration directly influences the bike's behavior:

  • shorter chainstays statically

  • but which lengthen at sag for stability

  • without becoming excessively long at the end of the stroke

The goal:

  • stability on rough terrain

  • maintained maneuverability in turns and technical sections

Size-specific geometry & kinematics

One of the rarer elements on the market:

  • geometry and kinematics adapted by size (S1–S4)

  • the dual idler layout changes depending on size

  • chain length remains constant across all sizes

  • Orion size specific geometry

Consequences:

  • different leverage ratio for each size

  • suspension “tuned” for the rider's weight and style

  • consistent behavior regardless of size

Frame and suspension

Nighttrain is also offered as a frameset, equipped with:

  • shock: Fox Factory Float X2, 230×65 mm

Frameset w/ Shock

  • Price: 2,499 USD

  • Weight: 4.63 kg (S2, with shock)

Complete Configurations

(All include: tubeless valves, sealant)

Shimano Deore — 4,999 USD

  • Marzocchi Super Z, 170 mm

  • Fox Float X2 Performance

  • Shimano Deore 4-piston

  • Shimano Deore M6100 SGS + M6100 cassette

  • Weight: 16.78 kg

Shimano XT Di2 — 6,999 USD

  • Fox 38 Factory Grip X2, 170 mm

  • Fox Float X2 Factory

  • Shimano XT Di2

  • Weight: 16.32 kg

Shimano Saint 190/170 DH — 6,499 USD

  • Fox 40 Factory, 190 mm

  • Shimano Saint

  • Weight: 18.14 kg

What else is on the market with similar concepts?

Nighttrain fits into a relatively narrow niche of bikes that combine:

  • mid/high pivot

  • idler pulley

  • gravity-oriented complex kinematics

Relevant examples:

  • Forbidden (Druid / Supernought platform) – high pivot with idler

  • Commencal Supreme DH – high pivot DH race

  • Norco Range C2 HP – high pivot enduro

  • Cannondale Jekyll (recent versions) – high pivot + idler

  • Deviate Highlander – high pivot with a focus on efficiency

What differentiates Nighttrain:

  • dual idler system (rare in the industry)

  • integration into a 6-bar Orion

  • size-specific kinematics approach, nearly non-existent at this level of complexity

Conclusion

RMU Nighttrain is not just another aggressive enduro, but an ambitious technical project that combines multiple advanced concepts into a single frame: Orion 6-bar, dual idler, and mid-pivot. The result is a platform clearly aimed at riders who ride hard and seek maximum control in challenging terrain.