VECTr – Variably Expanding Chain Transmission

Two of the Big Boys (the two biggest?) of bicycle component manufacturers, Shimano and SRAM, have both created quite a lot buzz with their patent applications for drivetrain components which would, in different ways, eliminate the front derailleur.

In January, the PTO published the patent application which Shimano filed for a frame integrated gearbox:

And the application that SRAM filed for a crank mounted (not frame mounted!) derailleur was published by the PTO in May.

What I think this shows if that even the Big Boys realize there are inherent problems with the front derailleur on drive trains and that they have invested significantly in R & D and patent costs and fees to come up with creative, albeit super-complicated  ways around what has been a mainstay of bicycle transmissions.

The fact that these major players in the bike component marketplace are looking seriously at alternatives to the front derailleur has driven interest in VECTr.

VECTr similarly eliminates the front derailleur and instead varies the size of the front driving gear by adjusting crank mounted gear segments. This keeps the chain in a consistent chainline. Shimano’s gearbox would do this, but only by requiring a heavy, complicated mechanism built into the bicycle’s frame. VECTr achieves gear changes while being mounted on existing bike cranks/bottom brackets, components compatible with standard frames. SRAM’s device would seemingly do this too, but it would also itself be a true derailleur and push the chain between only two discrete chainrings. Moreover, it would do so by incorporating tiny servo motors, batteries, a radio receiver, a timing computer and who knows what all else.

VECTr’s very great advantage over these proposed alternatives from SRAM and Shimano is that it achieves the same or better result than the devices described in the patent applications with a very much simpler design, and no doubt, at a very much reduced cost. Plus, VECTr is already patented!