Update – Markforged printed custom bike

November 2017 was the first blog entry about designing and building a custom carbon fiber reinforced recumbent…


Since then, many more parts have been printed and the initial frame assembly has begun. Some components that were commercially available as existing carbon fiber products were purchased from Amazon & eBay. These purchases included the front fork, stem, handle bar, and brake levers. Mechanical items such as the headset, bottom bracket, and a few threaded inserts were also purchased and successfully pressed into their respective printed counterparts.


Progress to date:

Most of the key components are printed and nearly all are in Onyx build material with either High Strength Fiberglass, Carbon, or Kevlar as the fiber reinforcement. One notable exception are the seat hinges which are in pure nylon to have the flexibility that will allow easy adjustment of the seat back angle.


As can be seen in the images, the individual pieces fit well within the print bed dimensions of even the Mark Two printer. To fabricate the frame, carbon fiber bicycle tubing was purchased from Rockwest Composites and cut to appropriate lengths with a diamond blade in a power miter saw. Bonding between the Markforged printed parts and carbon fiber tubing was achieved with some Loctite E-120 aerospace grade epoxy.


Not quite ready to ride:

Although the recumbent is not finished with enough time to debut in the Three Notch Century this year, it will be on display during a few trade shows and will see its first road test this Fall. Only a few accessory pieces remain to be printed; such as idlers for the chain, headtube spacers, and a few clips to manage the derailer and brake cables. To minimize problems between the chain and the rear derailer cable, it was possible with the printed parts to allow for the cable to feed through the right rear frame tube.


Current estimates show a 60% weight reduction in the printed bike versus the original Vision R40 recumbent base design. Stay tuned for a final review and first ride report.

John Nolin
Technical Representative, SolidXperts

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