Friday, October 17, 2014

Get on board with a US made cross frame

There's still a bit of time to get in the queue for a US made cross frame.  Cameron Falconer will, once again, be making these frames for Black Mountain Cycles.  Cameron's been getting some well deserved recognition recently, including this post on The Radivist.  Well done, Cameron.

Here's the skinny on the frame particulars.  We're doing both a disc and a rim brake frame.  Each one will be unique to its purpose and brake requirements.  In order to make this project work for both Cameron and me, we need to make at least 3 frames per size per brake type.  Right now, I have deposits for 56cm frames for rim brake and 59cm frames with disc brake.  If you want a 56cm disc frame, then I'll have three of those made.  If you want a 62cm canti brake frame, then I'll have three of those made. 

The particular particulars of the frames are:

Canti frame - This will be the same as the previous frame.  True Temper Verus tubing, Paragon Machine Works hooded type dropouts, s-bend chainstays, top tube cable routing, Pacenti Paris-Brest-Paris fork crown w/curved fork blades.  Geometry is the same as the Taiwan production frames.  

Disc frame - My first thought was to use a low-mount dropout to fix the disc caliper to the chainstay.  However, this is easier said than done if we want to make the frame have clearance for 45mm tires, 50/34 chainrings, and narrow q-factor road cranks without dimpling the heck out of the stay.  A low-mount makes it easy to mount racks and fenders, but does little to help with the actual fitting of the components that are likely to be used.  If we wanted to reduce tire clearance to a 35mm tire, that would be easy, but that's not what this frame is about.   

So, the disc frame will get the same s-bend chainstay as the canti frame and the same Paragon dropouts.  The brake will be mounted to the seat stay with some super clean disc mounts Cameron sources from another area builder.  There will be an hour glass shape braze on to facilitate rack mounting a rack and we'll have something for fender mounting as well.  

The fork on the disc frame will also be made with a disc brake in mind.  The slender, curved fork legs aren't, in my mind, a sufficient anchor for a disc brake.  Cameron and I talked about forks and we think a segmented type fork with straight legs and the Willits/Paragon disc tab will be the best design to work with a disc brake.  We will also make the wall thickness of the left fork blade thicker.  There will be eyelets added for fender mounting or the dropouts will have eyelets.  No provisions for mid-blade low-rider bosses.

Colors - two options there; either the same International Orange or a bright green RAL6018.  

Options - there are only two options available for either the canti or disc frame.  The first is a third water bottle boss on the bottom side of the down tube.  The second is eyelets on the front of the fork legs for mounting a small rack like the Nitto M18.

There you have it. Production will be happening at the end of October.

(What's playing:  Brasil '66 & Sergio Mendes Mais Que Nada)

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