bc40

SRAM X0 Eagle Transmission Bike

Current lead time 4 - 6 weeks.

$8,400

The BC40 was over two years in the making. Inspired by the now-legendary Back 40 trail system, it’s a thoughtfully engineered, modern cross-country machine. That means race-day lightness and sharp handling combined with all-day comfort and control. We tested and refined this bike right in our own backyard. The rocky ledges, dynamic corners, rolling climbs, and ubiquitous jumps and flow features informed the design. The BC40 sports 120mm of front and rear travel combined with a second-to-none pedaling platform for efficient pedalling performance. Progressive geometry ensures good weight balance for both climbing and descending along with stability at speed and through sketchy portions of trail.

The SRAM X0 Eagle Transmission Bike is where hi-tech meets rugged dependability. The X0 group features an all-new alloy crankset - SRAM’s lightest ever.  Like all Transmission groups, this crankset works in harmony with the flattop chain, wide-ratio 12-speed cassette, and rear derailleur to deliver crisp, quick shifts every time you tap the two button wireless remote shifter.

  • Recent improvements to BC40 include 100g weight savings, stiffer front triangle, stronger and more durable, co-molded bottom bracket insert, and a co-molded alloy insert for the main pivot bearing bores that improves bearing life and ease of maintenance
  • In-house development and testing that included building our own testing methodology and machines as well as testing our competitors' bikes to benchmark performance and tearing them apart to weigh each component item
  • Designed to stretch the capability of what a cross-country bike can do while making no compromises with weight and pedaling efficiency 
  • Aluminum suspension linkage, left-side dropout interface/brake mount, and cable management inserts machined in house to ensure the highest precision for alignment and component fitment
  • Built to exceed the expectations of multi-time Olympians and national champions, for ultimate performance at the highest level of competition
  • Inspired by decades of riding and racing, and purpose-built for the hundreds of miles of trails in our backyard

 

Key Features

FRAMESET WEIGHT
1950 grams (Lrg)
GEOMETRY
A slacker front headtube angle for predictable handling at speed across buff and technical terrain. A longer front-to-center measurement shifts the weight of the rider further behind the front wheel for more control to maneuver at high speeds.
SUSPENSION
Designed for 120mm front and rear travel, can be adjusted down to 100mm for optimal terrain performance. Faux bar system (four bar flex stay) kinematic designed for pedaling efficiency.
COMPATIBILITY
Cable management at the headtube allows for easy compatibility across components, including dropper posts and remote lockouts.
BOTTLE MOUNTS
Capable of carrying 2, 1 on the downtube and 1 on the seat tube
TIRE CLEARANCE
29x2.4

Build Kit

BOTTOM BRACKET
SRAM Dub 73 BSA
BRAKES
SRAM Level Silver Stealth 4-Piston 180 Front / 160 Rear
CASSETTE
SRAM XS 1295 Eagle Transmission 10-52
CHAIN
SRAM XO Transmission
CRANKSET
SRAM XO Eagle Transmission
FORK
Rock Shox SID Ultimate 3P Crown 120
FRONT DERAILLEUR
N/A
HANDLEBAR
Race Face Next R Carbon
HANDLEBAR TAPE
ESI Chunky
REAR SHOCK
Rock Shox SIDLuxe Ultimate 3P Lever
REAR DERAILLEUR
SRAM XO Eagle AXS Transmission
SADDLE
Selle Italia Model X SuperFlow
SEATPOST
Fox Transfer P-SE Dropper
SHIFT LEVERS
SRAM AXS Pod Bridge Controller
STEM
Race Face Turnbine R
TIRES
Vittoria Syerra 29x2.40
WHEELSET
Industry Nine 1/1 Trails S Carbon

Sizing Guide

SM MD LG XL
Crankset 170 170 175 175
Stem 40 50 50 50

Frame Geometry

SM MD LG XL
A. Stack 598 609 622 633
B. Reach 420 445 475 501
C. Front Center 710 739 775 806
D. Seat Tube Angle 76 76 76 76
E. Wheel Size 29" 29" 29" 29"
F. Headtube Angle 66.5 66.5 66.5 66.5
G. Fork Rake 44 44 44 44
H. Head Tube Length 95 105 120 135
I. Bottom Bracket Drop 40 40 40 40
J. Wheelbase 1145 1174 1210 1241
K. Chainstay Length 435 435 435 435
L. Horizontal Top Tube 569 596 630 659
M. Seat Tube Length 395 420 450 500
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Lighter and Stiffer

The BC40 is now 100g lighter than before. We optimized the carbon laminate schedule to carve out any excess weight that we could, and we did it without sacrificing the strength or stiffness of the frameset. In fact, the rear triangle is now stiffer than before. This means that all of your power gets to the ground as you fly up the climbs.

Lightweight BC40 on path

Lighter and Stiffer

The BC40 is now 100g lighter than before. We optimized the carbon laminate schedule to carve out any excess weight that we could, and we did it without sacrificing the strength or stiffness of the frameset. In fact, the rear triangle is now stiffer than before. This means that all of your power gets to the ground as you fly up the climbs.

Bottom Bracket and Main Pivot Upgrades

Along with the laminate optimization, we’ve made some behind-the-scenes upgrades to the BC40 bottom bracket and main pivot. Both changes involve co-molded aluminum parts that ease maintenance and increase durability. The new bottom bracket allows easier access for cable routing - a boon to home and shop mechanics alike.

Detail shot of BB

Bottom Bracket and Main Pivot Upgrades

Along with the laminate optimization, we’ve made some behind-the-scenes upgrades to the BC40 bottom bracket and main pivot. Both changes involve co-molded aluminum parts that ease maintenance and increase durability. The new bottom bracket allows easier access for cable routing - a boon to home and shop mechanics alike.

Chainguide

The BC40 gets its long awaited chainguide. It’s a small thing, but it makes a big difference. While clutch-type derailleurs and narrow/wide chainrings do an admirable job with chain retention, sometimes one needs that little bit more confidence. This chainguide bolts right to the existing receiver on the pivot axle. Max 34t chainring.

Chainguide

Chainguide

The BC40 gets its long awaited chainguide. It’s a small thing, but it makes a big difference. While clutch-type derailleurs and narrow/wide chainrings do an admirable job with chain retention, sometimes one needs that little bit more confidence. This chainguide bolts right to the existing receiver on the pivot axle. Max 34t chainring.

Ultralight DUET Bar/Stem

DUET is a handlebar and stem system that rivals or betters the weight of most one-piece cockpit systems, yet you still get the adjustability of a traditional two-piece system. Both bar and stem are among the very lightest in the market. The 780mm DUET Handlebar paired with the 50mm DUET Stem totals a scant 199 grams.

Ultralight DUET Bar/Stem

Ultralight DUET Bar/Stem

DUET is a handlebar and stem system that rivals or betters the weight of most one-piece cockpit systems, yet you still get the adjustability of a traditional two-piece system. Both bar and stem are among the very lightest in the market. The 780mm DUET Handlebar paired with the 50mm DUET Stem totals a scant 199 grams.

Customer Reviews

Based on 2 reviews
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T
T.M.
A Ride to Remember

As I pedaled through the winding trails of Bentonville, the Allied BC40 became my trusty steed. Its sleek design, precision engineering, and responsive handling made every twist and turn an absolute joy. The trail seemed to come alive beneath me, and I couldn’t help but grin as I tackled each obstacle.

But it wasn’t just the ride on this demo bike that left me in awe—it was the story behind the bike. Shane, from Allied Cycle Works, provided a fantastic tour of their manufacturing facility as these are made right here in the USA. As someone who values US manufacturing, this struck a chord with me. Allied’s commitment to quality, innovation, and supporting American jobs is commendable.

The Allied BC40 isn’t just a bike; it’s a testament to American craftsmanship. Whether you’re a seasoned rider or a newbie hitting the trails, this bike will elevate your experience. Kudos to Allied for bringing manufacturing home and creating bikes that inspire adventure!

K
Ken Sluyter
Everything you need.

This bike is super comfortable. Longer rides just seem easier. I did change the seat and went with the Reserve wheels. Changed the tires to the Mezcal’s. Also I’m not a dropper guy so opted for a carbon seat post. With these changes the bike dropped to 24 pounds even with bottle cage and Shimano XTR pedals. Fit and finish is like a high end sports car. I probably have a couple hundred miles on it now and I’m still excited to get on it. If you need a new bike “this is it”
I’m 5.11 and size Large seems perfect.