A while back I reviewed the TEC Alloy shock and spring package. Overall impression were good, though I never broke the shock down to inspect individual parts and pieces. Recently I got that chance.
Just as I mentioned in my previous article, these TEC Alloy Reservoir shocks are indeed very similar to an RFY. The similarities don’t stop at the outside either. Comparing the internals side by side, an untrained eye would struggle to tell the difference between the two makes. That said, differences do exist. Notably, the top out spring, or lack there of, is a rubber bumper on the TEC shock. Looking closely revealed that the TEC shock rod is a touch shorter than the RFY variant. This likely scales the rod to the shorter top out bumper. In contrast, the RFY needs a little longer shock rod to accommodate the taller top out spring. The TEC would also benefit from top out spring replacement, though not so dramatically as the RFY does. Additionally, preload reduction would also help riders who are lighter or have very light machines. The supplied coil spring is a little long even at maximum perch height and resultantly there is a fair amount of built in preload.
The TEC internals are decent looking components. The TEC shocks I tore down had some miles on them, but all parts looked clean and wear free. Again, it’s surprising just how similar these parts are to the RFYs, yet they are not identical. The pistons for example are interchangeable. That is to say, I could put RFY internals in the TEC shock body or visa versa. Yet, the RFY Model 1 Piston has 12 small holes radially in the piston whereas the TEC has 6 larger holes positioned radially. The TEC Alloy shock features shim stacks in various combinations top and bottom of the piston, again similar to the RFY. It’s impossible to make any conclusions on the difference in damping properties based on these observations. A shock dyno would be required to truly tell the difference. By hand however, I’d say the TEC is damped a little less than an RFY with the same shock oil.
Overall, it’s clear the the TEC Alloy comes assembled better than the RFY. There was significantly less air in the system than I would see in a new RFY, that said, the TEC Alloys certainly benefited from a proper rebuild. Even with moderate pressure in the canister the shock rod was slow to return to full extension. After my rebuild, the shock rod would return to full extension with about 45psi in the canister. My biggest complaint about the TEC Alloy is the substandard Schrader valve threading. Rather than using the a standard Schrader valve external thread, the TEC uses something else, and that means I can’t use the standard shock tool that works on every other set of shocks in the world.
Edit: March 26, 2015 (edited for my XS650 visitors)
Here is the most current spring rate graph I have regarding the TEC shock package. Based on some calculations, the TEC HD spring is likely about 20 lbs./inch stiffer than the standard spring that is shown in yellow below.