Frame Technology

Understanding Frame Efficiency

Butted Tubing
Relative Weight Index


The IsoGrid® Story


Another way to improve efficiency is through the use of superior alloys. Our aluminum tandems, for example, are made from an alloy that’s 56% stronger than the aluminum used by our largest competitor. With every type of frame material—steel, aluminum and titanium—Santana has obtained custom drawn tubes in the best available alloy.

Besides larger diameters, thinner walls and stronger alloys, Santana uses many other innovative techniques to further boost performance, efficiency and comfort. An example, see function-specific tube shaping.

Setting the standard

It’s easy to become confused when every bike builder on the planet makes great sounding claims about the performance of their tubing and geometry. How is it possible to separate fact from fiction? In the case of tandems Santana alone employs measurements collected from dynamic strain gauge testing (electronically recorded during test rides). We use this data and information gleaned from the world’s only tandem test jig to refine and improve our designs.

In addition to testing our own products, we purchase and test our competitors’ offerings. And since instrumented testing can’t duplicate the human dimension, we also assemble panels of test-riders to score and evaluate the bikes we build against the best efforts of others. Finally, we benefit from the feedback of 50,000 Santana owners who have experienced 50 million miles of shared fun.

Unexpected results

While the best way to make a tandem stiffer and more stable is to use larger diameter tubes, Santana’s electronic strain-gauge testing has pinpointed two interesting exceptions. First, because measured flex across the top of a tandem frame is relatively low, testing disproves the popular notion that larger top tubes are worth their extra weight. A better answer is to enlarge the drivetrain- stressed tubes between the fork and rear axle. Second, while one overly large drivetrain tube certainly looks impressive, it can hurt a frame’s overall performance by transferring undue stress to adjacent tubes with insufficient diameters. Thus, an enormous bottom tube is actually counterproductive unless combined with proportionally-scaled downtube, seat-tubes and chainstays.