Product: Cyclocross Fork 3.0 for Seven Cycles

February 21, 2012

in Product Design

Seven Cycles Disc-Specific Fork 3.0

“A simple enough project that we’re going to make very complex.”  – Rob Vandermark

This fork began as a next-generation cyclocross fork to accommodate a disc brake. The design has expanded and re-centered to be a multi-purpose fork that’ll work for any kind of road, ‘cross, utility, or gravel-road riding that might benefit from disc brakes.  We’ve taken on the expansive design mission of Seven’s 5E fork and are applying it to this next-generation 5E.

Some of the primary characteristics of this fork include:

  • Disc specific – disk only
  • Handling comes first – before weight consideration
  • Iterating the basic design of our 2.0 cross fork – it is a very successful design but not disc compatible
  • Integrated carbon steerer and fork crown
  • Tapered fork crown – because that’s what everyone wants, whether it’s better or not
  • Integrated disc brake housing mounts
  • Aluminum dropouts for durability – none of that ‘carbon under compression’ stuff
  • To work with any 700c x 44c knobby tire
  • To accept fenders – a mounting hole in the crown of the fork, and a new (?) style of mounts at the dropouts.  Originally we were going to go with these but I think I’ve come up with way to integrate fender mounts without them being visible.  Note:  the current posted drawing is incorrect regarding the dropout fender mounts.

The primary challenge is making a disc specific fork ride well without it being too stiff.  The torsional forces a disc brake puts on a fork leg is problematic.  Braking steers the bike.

Here’s A Bit of History 

Version 2.0

Seven Cycles introduced its second generation cross fork in 2007.  One of the primary solutions we brought to market was eliminating cantilever brake chatter that existed with nearly every molded carbon fork on the market.

Version 1.0

Seven Cycles’ first cyclocross fork was built by Advanced Composites.  We worked with that fork for many years – since 1997.

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Project timeline in reverse:

Oct 22  |  Renaming this to “disc fork” design – or something like that.  We don’t want to limit this fork to a narrow ‘cross race function.  To that end, I worked on a light mount based on a suggestion from John Bayley today.  I think it would be an add-on to the fork but look very integrated.  No promises.

Oct 18  |  Worked on a fender mount system today.  Different from what I’ve seen before.  I have high hopes.  Integrated.  Hidden.  Simple.

October 16  |  Working on the Seven disc fork design for cross and touring.  Frustrating.  When does ride characteristic get pushed aside for perceived technology improvement?  Isn’t ride control most important in cycling – more important than grams, fad, early adoption?  I like to live in a black and white world.

September  27  |  Scratching at the disc brake cross fork itch again today – for Seven Cycles.  I’m very conflicted about this item.  Disc brakes on road bikes have lots of issues.  A good disc brake cross fork does not a good road fork make.

February 21  |  Enough talk, now it’s time to get this disc fork going.  The plan it to have the fork ready for spring 2013.  Sounds easy enough.

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