Boone Technologies

A chainring kind of day! 50 and 34 tooth in a 110mm bolt circle.

Here’s a raw as-welded spindle insert section on my titanium cranks. It has my 8 lobe spline system that also contains threads for a lockring on the drive side or a preloader for the non drive side. The part is the same for either side, which means it could also work for tandems. The spline accepts either my direct drive chainrings, spiders, or adapters to fit other spline systems.

After about a year of development, my TwistTi cranks are finally here. They are made from all 6al4v aerospace grade titanium. Available on the www.BooneTi.com website.

This set of rollers was my second attempt at forming the twisted shape of the laser cut titanium sheets for my TwistTi concept. The first was dies, that didn’t work at all! I had bent one in a mill vise with a huge Crescent wrench. The rollers here were a little different in that one end was clamped firm to a rotary axis and this stayed upright and moved in the length direction. It had a major problem; titanium is so springy that even twisting the part over 360 degrees, the part relaxed back to around 45 degrees. Also, thin parts bent more than thick parts. I would have to rethink the whole bending operation.

In my continuing saga of pursuing titanium cranks, I had a thought; what if they were made in 4 laser cut continuous sheets and welded in that shape? I laser cut some thin aluminum sheet and bent the sheets by hand and duct taped them at the corners. The concept looked possible but the trick would be to bend the titanium to the correct shape. Should be easy, right!? 😜

This was my first attempt at making a titanium Twist crank over a year ago. I laser cut about 80 cross sections and laser welded them together, one by one. Although the concept worked, it was extremely labor intensive. It showed the potential of what it could be.