The steering system consists of your handlebars and your stem. (The stem is the angled, metal shaft that connects your handlebars to your bicycle fork and front wheel.)
What Needs to be Checked?
- Your handlebars should be checked to make sure they are securely anchored in the bicycle stem.
- The stem should be checked to make sure it's lined up properly, securely anchored, and that the extension limit (the furthest point that the stem can be safely extended upwards) hasn't been exceeded.
A quick check of the steering system should be made before every ride.
Check Procedures
- Road bike handlebars - Stand facing the front of your bike, with
your legs on either side of the front tire. Place your hands on your brake
hoods, then gradually put your weight on them. The brake hoods (and your
handlebars) should be able to support your weight without rotating downwards.
- Mountain bike handlebars - Follow the same procedure as above, but
place your weight on your bar end extensions. If you don't have bar ends,
try rotating your handlebars by pushing on your brake lever bodies. If you
notice movement during either of these tests, check closely to see if your
handlebars are rotating in your stem or your bar ends or brake levers are
loose instead.
- The stem - Straddle your bike facing forward and hold the bike frame steady with your legs. Turn your handlebars so that they are perpendicular to the frame. Check to see that your stem lines up parallel to both the top tube of the frame and front wheel. Then make sure that your stem is held firmly in place and that the minimum insertion line is not visible on the stem. Make a quick visual inspection to verify there aren't any cracks or other damage to the stem.
- Handlebar movement during the check procedure
Solution -
If you notice handlebar movement, check to see that the handlebar clamp
bolt(s) is securely tightened. Different bicycles will have different clamp
bolt designs, but this bolt should be easy to locate and tighten. If there
is still movement after tightening this bolt, consult an experienced mechanic
for advice on how to proceed. - Stem movement during the check procedure
Solution - If you notice stem movement during your stem check (or if you just need to adjust the position of your stem), you can make changes by loosening the stem expander bolt. The stem expander bolt is a hidden bolt located inside of your stem that connects the stem to the top part of your bicycle's front fork.
The specific tools needed for this adjustment will depend upon the specific type of expander bolt you have. The bolt head itself should be located at the top of the vertical section of your stem, right where the stem bends to meet the handlebars. To make adjustments, loosen this bolt about 1/4 inch, or until the stem rotates freely. Be careful not to loosen the expander bolt too much -- doing so can cause the expander nut to fall off and drop into your fork tube.
If your stem is still difficult to move even after the stem expander bolt has been loosened, try tapping the bolt head firmly with a padded hammer. This should jar the expander nut inside the steering column free.
Once you've adjusted your stem and have it in the right position, simply re-tighten your stem expander bolt so that it holds the stem firmly in place. Be careful not to over-tighten the bolt, since over-tightening can lead to expensive fork damage.
A note on stems and brakes
Before performing any stem adjustment (other than a general tightening of the expander bolt), check to make sure that your brake cables are not in any way attached directly to your stem. If they are, your brakes may be affected by any significant stem movement, whether it's up, down or side to side.
If you have a braking system that attaches directly to your stem, either leave stem adjustments to a experienced mechanic or take a bike maintenance course to learn how to re-adjust your brakes after adjusting your stem. - Stem extended beyond its limit line
Solution - Stems are similar to seat posts in that they have limits to how far they can safely be extended out of your frame. If your stem limit line is visible, don't ride your bike until the stem is safely reinstalled below the limit. If you can't ride your bike comfortably without the stem extended beyond its limit line, stop by your local REI and discuss your options with an experienced REI bike specialist.
Your handlebars should not need specific cleaning as part of a basic maintenance program. Simply wipe them down from time to time to keep dirt and grime from getting into your brake and shifting levers.
Your stem shouldn't need a lot of cleaning either, but the junction between your stem and your bike frame can become corroded. To prevent damage, coat the unexposed section of your stem with a thin layer of bicycle grease any time you remove it and reinstall it.