Expert Answers
Shopping for a Front Shock

I'm planning to buy a front suspension fork, but I don't know what type to choose. I use my mountain bike primarily for asphalt, as well as for downhill riding on a local mountain, which has some really steep and bumpy hills. What should I opt for?

Steve Jones's Answer:

	Steve Jones The author of four mountain-biking books, Steve Jones has logged thousands of miles of trails and backroads. Meet Steve Answer Archive Biking Forums

The main purpose for a front shock is to reduce the force that bumps transmit through the handlebar. They provide surer handling and reduce the jackhammer motion that can cause hands, wrists, elbows, and shoulders to ache. Overall, equipping your bike with a front shock is a sound move if you plan on biking off-road.

There are three types of front shocks, each with advantages and disadvantages. The type of shock depends on the way the bumps are smoothed or"dampened." Air shocks use an airtight chamber similar to what is found inside a pump. It's much more sophisticated, of course (not to mention more expensive), but has the distinct advantage of being almost as light as, well, air.

1. Air shocks are commonly used for the rear shock on a full-suspension bike. Besides being expensive, air shocks — by virtue of using air as its dampening medium — change their response after the air inside gets heated up. For this reason, they are difficult to set up for all conditions. Their initial response to a bump can also be slower unless the force is large — like what you would expect to have happen when descending a hill at a high rate of speed, e.g., greater than 25 MPH. For the purely recreational rider, then, air shocks offer a less-suitable answer than other options.

2. Another shock option employs Elastomer, a type of rubberized plastic; Elastomer is used to produce rings that are then stacked on top of each other inside the shock chamber. The fork arms compress against the rings. Since the rings retain a shape "memory," they tend to return to their original shape when not under pressure. However, these shocks tend to require high maintenance, wear out more quickly than air shocks, and change their response when heated or cooled. But they are not as heavy as the more reliable type of dampening mechanism used in front shocks: coil springs.

3. Steel-coil springs are the easiest to adjust for an individual rider's requirements. The technology is cheap, simple, and dependable, but it comes at a cost that many "serious" recreational, cross-country riders aren't willing to pay: weight. The added weight, however, isn't as big a deal for those whose idea of mountain biking is zooming downhill without having to touch a brake lever.

There are many companies that make shocks, with several styles to choose from. Determine what your needs are (indeed, if you even have a need for front shocks), talk to riders who have front shocks, and try to pick out the set of shocks that has the lowest maintenance, weight, and price but with the highest performance. You may be able to pick up a set of used shocks significantly cheaper than new, but be prepared to spend some to get them rebuilt.

Hope this helps.