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 Shimano XT M8100 Bike is our least expensive BC40 offering, and it is a real workhorse, anchored by the venerable Shimano XT 12-speed mechanical groupset. Perhaps you’re wary of the electronic offerings from SRAM or perhaps you’ve been a die-hard fan of Shimano’s trigger shifter sensation for many years. Either way, this bike offers smooth reliable shifting and what many folks consider to be the best braking performance in the industry.
- Recent improvements 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
- Shimano XT BB-MT8000 BSA
- BRAKES
- Shimano XT BR-M8100 180mm/160mm
- CASSETTE
- Shimano XT CS-M8100 12spd 10-51
- CHAIN
- Shimano XT CN-M8100 12spd
- CRANKSET
- Shimano XT FC-M8100-1
- FRONT DERAILLEUR
- N/A
- HANDLEBAR
- FSA SL-K MTB Carbon
- HANDLEBAR TAPE
- ESI Chunky
- REAR DERAILLEUR
- Shimano XT RD-M8100 12spd SGS
- SADDLE
- Selle Italia Novus Boost
- SEATPOST
- Fox Transfer Performance 31.6
- SHIFT LEVERS
- Shimano XT SL-M8100-1-R 12spd
- STEM
- FSA Gradient
- TIRES
- MAXXIS Rekon 29x2.40 WT EXO/TR Tan Wall
- WHEELSET
- Industry Nine 1/1 Trail S Wheelset
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 |