BMC Timemachine Mpc. Frameset

The BMC Timemachine Mpc. Frameset is BMC's dedicated time trial and triathlon frame, built in Grenchen, Switzerland from Mpc. Premium Carbon. It is an aero frame designed around an integrated front end, with the base bar built into the Halo+ fork instead of a separate stem and bar. It is made for riders who already know the position they want and are ready to assemble a complete build around it.

An integrated front end

The defining feature is the cockpit. The Halo+ bayonet fork carries a flat aero basebar as part of the fork, so the frameset has no separate stem. The basebar is 353mm wide outside to outside and 328mm center to center on both sizes. You add extensions to suit your position: BMC lists custom extensions or the Profile Design Aeria 1. Because the front end is fixed, your position is adjusted through the extensions and the seatpost instead of swapping stems, which is why BMC recommends a professional fit before you order.

The fork is made from Mpc. Premium Carbon with a stealth dropout, flat-mount disc brake and a 100x12mm thru-axle. The idea behind the integrated design is to keep the front of the bike clean, with the bar, fork and brake working as one shape in the airflow. As with any aero claim on a frame like this, BMC's design intent is not the same as independent test data, so treat the gains as manufacturer claims.

Frame design

The tubes use deep, truncated airfoil shapes, a common approach on time trial frames, where the shape is cut off rather than tapering to a point. Cables are routed internally, and the frame has room for hidden hydration and storage, which helps on long triathlon courses where you need to carry fluid and nutrition without adding drag from bottles on the outside of the bike. The frame also accepts a bottle cage.

It uses a full-mount UDH dropout, which allows direct-mount derailleur compatibility, and a 142x12mm rear thru-axle. Braking is flat-mount disc, with rotor sizes of 160mm at the front and 140mm or 160mm at the rear. The maximum tire width is 30mm, on 700c wheels.

Geometry and position

The Timemachine comes in two sizes, S and M-L. Seat tube angle is 75.2 degrees on both. Chainstays are 410mm and BB drop is 80mm. Seat tube length is 507mm on the S and 537mm on the M-L. The seatpost is a forward-configuration design in Mpc. Premium Carbon, with offsets of -5.5, -18, -30.5 and -43mm, and BMC also lists an optional standard post with offsets of -18, 0, +18 and +36mm. The forward design suits a steep, aggressive position, which is common in triathlon, and the range of offsets gives your fitter room to dial the saddle in.

Build requirements

This is a frameset only, so the build is up to you. It includes the frame, fork, seatpost and headset. The bottom bracket is not included and you will need a press-fit 86.5mm road bottom bracket. A braze-on front derailleur is required if you run a 2x setup. Wheels, drivetrain, cranks, saddle and extensions are all separate. BMC lists a maximum system weight, rider plus bike, of 242 lb, so heavier riders should check that figure.

The BMC Timemachine Mpc. Frameset is for serious time trialists and triathletes who want a Swiss-built aero frame and are willing to put the time into a proper fit and a considered build. It is a significant investment, and it makes the most sense for riders who will race on it.