We experimented with more than a dozen bolt head shapes and diameters before finding these amazing 6Al4V Titanium aerospace screws. The SILCA bottle cage screws have an 11.6mm Diameter low profile flange head design. This is more than 3mm larger than a standard bottle screw, which . The low profile head saves weight while also better distributing stress under the head of the screw, which allows it to distribute load across nearly 3x more surface area than a cap screw and more than 2x the surface area of a button head providing both increased rigidity AND lower stress!
Each bolt is machined complete in one operation from 6Al/4V Titanium on a Swiss Lathe. Threads are roll formed for peak strength and material grain alignment in the finished screw.
Kit includes 2 screws, 1.5 grams per screw.
During the initial development of the Sicuro Ti bottle cage, we found ourselves developing a suite of bottle cage test equipment. After some 20 years in the industry I had realized that a bottle cage was the sort of thing that was frequently made, but never tested.. in fact there exist no standards or equipment for doing so, and that felt like an opportunity for improvement to the team at SILCA.
We ultimately developed 3 different tests to help us understand how to make the world's best cage.
1. Multi-axis shake test. This test allows the engineers to shake the bottle and cage at different frequencies and amplitudes while also mounting the cage/bottle at different attitudes. This allows us to simulate bottle retention in different positions on the bicycle, downtube, seat tube, beneath the downtube (becoming common on gravel bikes), behind the saddle (as on a tri bike), etc..
2. Insertion-Removal test. This is one of the most interesting tests in that we can both fatigue cycle the bottle cage to simulate bottle insertion and removal over thousands of cycles, but the equipment is fully instrumented so that we can test for insertion and removal force at various angles and attitudes. One of the most interesting learnings from this test has been the debunking of the myth that stiffer cages with higher insertion/removal force will always hold bottles better. In fact, many cages with high insertion/removal force also struggle with high frequency vibration where the high holding force holds the bottle in place as it walks out the top of the cage.
3. Fatigue Test - This test is the most severe of the 3, using a pneumatic cylinder to simulate a 4G lateral impact with a full bottle which is 2x the highest force measured in on-bike testing and equal to the force measured in a heavy mountain bike crash. Some of the benchmark cages we tested were broken or permanently deformed in only 1 cycle of this test, many others fail in the tens of cycles. Sicuro Ti: 2500 cycles