Quiring Cycles

The mountain bike crowd has shown a lot of interest in using the Cannondale XLR Carbon Lefty on their 29'er these days!  

About three months ago I started on this project to integrate a Quiring Titanium frame with the Lefty, the Cannondale SI stem and, the bearing system.  The benefits to this are simple to explain.  When using the integrated system, the Cannondale engineers have found a way to make a bike using a lot less material.  For example, much of the headset weight is eliminated since the bearings are pressed directly into the Quiring frame.  Also the SI stem is extremely light because it is one piece with the steerer and does not use extra fasteners, or pinch bolts, or material overlap to join together.  Additionally, the Lefty itself, being carbon fiber, is the lightest suspension device out there that joins the front wheel to the frame.   This means the Cannondale components integrated together are a lot lighter when compared to conventional headsets, stems, and forks.   Last but not least, the Lefty XLR Carbon fork has top notch suspension characteristics which include threshold dampening and adjustments that can be made remotely at the handlebar, such as a lockout mode.  

The challenge for a titanium framebuilder, such as myself, was in creating a headtube that would integrate with the Lefty and the rest of the Cannondale integrated system.   First, I had to tightly machine a headtube to its outer profile.  Step two in the development was that I used a custom-built proprietary system during the welding stage to maintain proper tolerances of the titanium headtube.   Titanium has a high degree of thermal expansion and a good deal of thermal conductivity so it is easy during welding for the headtube to become extremely distorted and "out of round".  Therefore, the technique I used is essential to provide a stable atmosphere and structural integrity needed to keep the headtube straight and true to size.   This then allowed for the final step which was the precise post-weld machining of the bearing seats using a specially created process where we sweated over +/- .0001 inch in the precision.   The result was a perfect bearing press fit where the headtube bearings run true.  And no play or tightness in the headtube bearings could be found so the bearings will run smooth for years.  I also have production setup so that I can make more of these frames and also help to provide Cannondale SI components.

Not withstanding, the custom Quiring Titanium 29'er frame is top notch quality as well using seamless 3/2.5 tubing, 6/4 ELI double-pass continuous back-purged welds and some fancy dropouts and other parts from Paragon Machine Works.  The finish was etched logos with a satin overlay and a fine silver Quiring headtube badge. 

Also note a BB30 has been used on the frame and is ready for Cannondale Hollogram SL XX cranks, which are also very light and stiff.  We will build later today into a complete bike and post some pictures soon.  I am excited to see the results as I believe it will be one of the most amazing setups that could be used for cross country racing yet!--  Scott Quiring