Squish This! Suspension Terms Explained!

Hallo! In the world of endurance mountain bike racing, suspension on the bike can be seen as a necessity. You,ve got to stay as fresh as you can, for as long as you can. (Rigid, singlespeeding, pain freaks not withstanding!) Today, I attempt to uncork the pandora's box of suspension tech terms, AND explain them! Stand Back! Here come the hairy little critters!

Really, it's not that difficult. We have three basic areas to be concerned with. Spring type and rate, compression, and rebound.

1. Springs: Well, it is what makes the fork "sproingy". You can use air, metal springs, elastomers, or whatever will absorb energy by a reduction in it's physical size, and be able to return to it's original state after the "bump" energy has been dispersed. (Usually, as heat) Usually, your spring is inside a "shock" body, so you can't see it. On rear suspension that uses coil springs, the spring is readily visible. ( Oh, I suppose some front forks too!) Spring rate can be thought of as how "fast" a spring will "contract" as a given amount of force is applied to it. This rate can be variable throughout the process of absorbing a bump. For instance, an air spring will be harder and harder to compress, the closer it gets to it's maximum ability to absorb a bump. Thus, it's spring "rate" is said to rise as a result of this phenomenon. Basically, in neandrethal terminology, a rising rate means ,"gets stiffer", while a falling rate means, "gets softer". Guess what a constant rate does?
Tuning Options: Usually "pre-load". Pre-load is a way to "stiffen" up the spring, usually causing it to have a harsher ride over smaller bumps. Or, of course, you could lessen the amount of pre-load, making the suspension more reactive to smaller inputs.

Compression: This is what is going on while your suspension is absorbing bump energy. This is, of course, related to what your spring does. But, compression is a little more complicated. Simply put, it's what your shock does to control how the spring reacts to the absorbing of bumps. Some people will refer to it as "damping". NOTE: I did not write, "dampENing" as that is, what.........HILLBILLY SPEAK! Okay, let's make it really simple. Bumps are like FIRE. The fire attacks your springs, causing them to retract in horror. Then, "damping" comes along, all wet and oily, to cool down that fire, and make things NIIIIIIIIICCCCCCCEEEE!!!!!! Ahhh! That bump wasn't so bad now, was it?

Rebound: NO! Not Dennis Rodman! This ain't no game, here. When that suspension wants to return to it's resting state, after absorbing that bump, it wants to get there NOW! So, we have another little control, called "rebound". Try dropping your bikes wheel on the ground once, when it's off the bike. BOUNCE! That is a great example of NO REBOUND CONTROL! Most modern suspension controls the "speed" at which a shock can return to its resting state. This can be adjusted on some shocks, so you don't get catapulted into the windsheild of a delivery truck.

Well, that wasn't so bad! Oh! I almost forgot! A little blurb here on "platform" technology. Basically, the "Holy Grail" of bicycle suspension all along has been to get the bicycle's suspension to absorb the hits, but not react to the riders squirelling around from above. Most commonly called "bob". "Bob" is the devil! Well, now suspension designers have tweaked compression to only react to a pre-set level of force, striking a balance between rider input and bump forces. I am not a huge fan of most of the designs out there. I will say that Fox has got a really interesting system on their forks that Jeff uses. I am very impressed by it. I'll let Jeff tell you about that ,though!

What I Say: Get to know your shocks adjustments, and play with them! It won't make you go blind! I think that suspension tuning for individual courses is one of the most highly unused resources for the endurance racer! Make your body happier! Tune that suspension!

By the way, last weeks musical referance was "Elo Kiddies". Cheap Tricks first hit single. No- no body got it! Look for this weeks clue, and see if you can "get it". Sooner! Peace! Guitar Ted!