NOTE: The following test results were generated by the original Z-Link system. However, similar outcomes can be achieved by systems that provide the same dynamic performance.
Test 1 was performed by pedaling over a short test track that simulates firm pedaling up a slope and also over a bump. This test is configured to evaluate the pedaling performance of each system under pedaling load including over bumps, while also ensuring consistent and repeatable testing.
Test 1 consists of starting from a standstill on roughly even ground, then pedaling up an incline with a bump midway of about 35 mm height and finally coasting at the end as the incline flattening out. The start had a small ledge (~10mm) which was initially used for practical reasons (to start at the same location consistently), but as shown by the results, this feature itself highlights some performance advantages of the SCD system.
The following graphs show the shock movement results of the SCD Prototype 1 compared to 3 other contemporary systems during test 1. These results highlight how the SCD system generates less suspension movement during pedaling and also that it remains active over bumps and actually absorbs bumps far better.
Note that Brand A, Brand B, Brand C are all high performance bicycles at or near the top of the range from well known Bicycle companies. Further information will not be disclosed publicly.
Specifically, what this test shows is that the provision of high anti squat forces by other systems (Brand A & B) generates unwanted suspension rise during pedaling over bumps. (Note that Brand A and B are very different systems despite the similar results.)
Brand C was found to perform distinctly differently to Brand A and B. Upon evaluation it was found that Brand C has significantly lower anti squat performance around the sag point. As a result Brand C almost matches the VAST system over the bumps by not generating unwanted suspension rise. However, the clear negative outcome of this systems performance is then the significant system squat during pedaling.
Only an SCD system can provide high anti squat where it is needed and low anti squat when anti squat is not needed.
Note that a short summary of the testing process is provided below.
Test 2 was performed by pedaling over the same test track as Test 1 except that the test was started at the bump midway through Test 1 so that the bump acts as a ledge. This test is configured to simulate pedaling up a hill which includes climbing up over a root or ledge at slow speed. (This situation might be typical of a steep pinch or switch back near a tree where erosion has exposed the tree root).
As it is very difficult to replicate dynamics when getting over a root or ledge at slow speed, the test run was configured by starting from a standstill with the rear wheel up against a ledge of about 35 mm. After clearing the ledge it was necessary to apply firm pedaling to climb the proceeding incline.
The results indicate similar outcomes to Test 1. These are provided in the below graphs.
Brand A and B exhibit significant unneeded suspension rise when clearing the initial ledge. This is extremely unhelpful as it indicates the rear suspension is extending significantly at the bump - the complete opposite of absorbing it. What is not shown in the graphs is the difficulty the rider faces to force the rear wheel over the ledge through significantly increased pedaling effort.
Brand A and B also show higher levels of suspension oscillation compared to the SCD system once the ledge is cleared as the rider applies pedaling force to build a little speed.
Similar to Test 1, Brand C, with its low anti squat performs quite well when it comes to clearing the ledge. However, the lack of anti-squat is exposed as pedaling force is applied after the ledge. Initially the suspension compresses significantly as the low anti squat lets the chain force pulls the system down (using up around an extra 3rd of the systems travel below the sag point). Thereafter, when pedaling to build speed, the system oscillates more significantly than the VAST system, and that oscillation occurs in a sagged position due to the low anti squat the system provides around and below the sag point.
In comparison to these result, the SCD prototype 1 provides far superior performance. The SCD system has minimal suspension rise at the starting ledge. It clears the ledge easily, does not compress unnecessarily after the ledge, has minimal suspension oscillation and travels near the sag point during firm pedaling.
Bike Set Up
Shock Set Up
The Human Element