Bob Newby told me that a belt should be around the same tension as a chain. With mine installed on the racer, I found the tension to be exactly this way, and yes no shock absorber used. I do think that because the belt has little or no mass ( inertia) by comparison to a triplex chain, that is a huge benefit over a chain alone, and there would be some give between the crank and clutch pulley's, even if only slightly. Because a racer is always being looked over and maintained, I feel any issues or faults with the belt would be found. The only 2 faults I have seen are if the belt is run out of alignment, or else damaged due to a bolt or stone going through it. Timing belts on cars usually fail due to age ( many heat cycles) and a section of teeth shear off in one hit. Only mechanical failure I have found was a bolt that came loose in the front timing cover and punched a hole through the belt. The late model Harley's have a very narrow rear drive belt now, much narrower than earlier bikes..........Greg.