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This page was last updated 21 August 2018.
The handlebars are held in the center by the stem. On road bicycles, the stem is angled downward to compensate for the angle of the steering tube of the bicycle frame, such that the top of the stem that holds the handlebars is horizontal. There are stems that angle upward, but this raises the handlebars and forces the rider into a more upward position that increases wind resistance.
There are various types of aero bars, also called triathlon bars. The most common types are clamped to the top of the handlebars. There are many different types. My current favorite is Syntace, despite the prices that border on extortion (little required pieces of plastic need to be bought separately at unreal prices). They clamp on the thick inner part of the handlebars, leaving more room for holding the top of the handlebars, they have a very low height and comfortable and adjustable armrests, and they have just the right length and a steep front that doesn't require bending the wrists too much.
Are aero bars necessary? This depends on the kind of riding you do.
I began using them when I had a 19-km ride to work every day into a
persistent headwind. They also offer an edge when it's my turn at the
front during group rides. They are not useful for short trips, and
they can be dangerous in the city because it takes longer to reach
the brakes, and because they move the center of gravity forward and
increase the danger of the rear wheel losing contact with the ground
when braking. They cannot be used when climbing hills. They should
never be used with old-fashioned brake levers with brake cables coming
out of the top because it's easy to get one's gloves caught when reaching
for the brakes.
Adjusting the Handlebars
The lower part of the stem should be long enough to raise the top to about the level of the top of the saddle, or a few centimeters lower. Lower position decrease wind resistance but put more strain on the neck muscles. The top of the stem is not normally set higher than the top of the saddle. The length of the top part of the stem should be chosen depending on the length of the top tube of the frame; usually it's longer for people with a long upper body compared to the length of the legs. Care should be taken to choose a solid stem that does not flex when pulling hard on the handlebars, like when standing to get up a steep hill.
Some people recommend to adjust the drop handlebars such that their ends point to the center of the seat tube of the frame (the one that runs from the bottom bracket to the seat post). This makes me feel like I am sliding off the ends, so I adjust mine to be almost horizontal, angled downward very slightly. The straight section in the curve allows an angled hand position anyway. This angle must be chosen before anything else is installed.
The brake levers are adjusted next after choosing the angle of the handlebars. They should be installed such that they can be comfortably held with your hands on the brake lever body, and they can be reached easily when the hands hold the curved part of the handlebars. For me, this means that the rubber body is about horizontal, installed at the forward-most (vertical) section of the handlebars. This must be done before installing the handlebar tape and cutting the cables; it's very difficult to make adjustments later. Do not use "safety brake levers" that have an extra lever that extends back towards the stem; they brake poorly and give a false sense of security.
The aero bar angle is also pretty much a matter of taste. I prefer the aero bars angling slightly up towards the front end. Any larger angle would hurt my forearms resting on the armrests.
Before wrapping the tape, install any brake and shifter cables that run to the brake handles or the bar-end shifters, using the grooves in the handlebars if available. Tape the cables to the handlebars with electrical tape to they don't come off all the time during wrapping.
Wrapping begins by attaching the short strips to the metal strap that holds the brake levers to the handlebar. Fold back the rubber coating of the brake lever body. Next, cut off one edge of one of the long handlebar strips so it tapers towards the end, remove the end of the backing to expose the adhesive strip, and begin wrapping at the end of the handlebar (not at the center near the stem). Wrap clockwise on the right side and counter-clockwise on the left side, seen from the rear of the bicycle (this prevents unwrapping when holding the handlebars on the top later). Wrap under tension, but not enough to stretch the tape significantly. The loops should be spaced such that the adhesive strip is just barely on the handlebar, not on the previous loop of the tape. I tend to space the loops more closely near the end and wider near the stem.
When you reach the brake lever, make sure that the last loop folds against the brake lever body. The next loop extends all the way to the other side of the brake lever body. Some people recommend to then fold the tape to run back along the lever to the lower end and then back over the previous loop than spanned the body, only in the other direction so it crosses the previous loop, but I find it makes the brake lever section too fat and wastes too much tape. Then complete wrapping the tape to the place where the handlebar gets wider near the stem, taper the ends again, and seal the end with electrical tape or the adhesive strips in the handlebar package. I usually have to re-wrap the last part after the brake lever a few times to get the length just right.
If you have aero bars that clamp on the narrow part of the
handlebars, not the wide part near the stem, remember to leave enough
of the handlebars untaped to install the aero bar brackets. When
folding back the rubber brake body coat no part of the handlebar metal
should be visible. For this purpose, put a 10cm piece of tape across
the clamp that holds the brake handle, with the ends disappearing
under the rubber cover of the handlebars after they are peeled back
What is a headset?
The headset is the pair of bearings on both ends of the head tube of
the frame. Installing a headset involves pressing cups into the head
tube and a ring onto the fork, which can't be done without expensive
tools that align all three to be exactly parallel, which usually
requires filing off uneven paint. It's one of the few things I let the
bicycle shop do.
Selecting a headset
The selection of headsets depends on the length of the fork. The
fourth, remaining bearing race is part of a nut that is screwed onto
the threaded top end of the fork after it has been inserted into the
head tube. Some headsets need more threading to stick out at the top
of the head tube than others. If the fork is too long, spacer rings
can be inserted, but if it is too short you are restricted to a small
selection of headsets. Unfortunately, the rather poor-quality Shimano
headsets are among them, which could force you to stick with the same
poor headsets. I broke quite a lot of them until I spent an enormous
sum on a Chris King headset, and never again had any trouble. I am
convinced that if the sun ever goes nova, nothing will be left of
our planet except hot gas and orbiting Chris King headsets. They are
indestructible and worth every penny.
Checking the adjustment
Headsets break when the bearing balls crush the hardened surface of the bearing races. This happens when the metal of the races is too soft or the headset is loose, so that the balls bump about and smash into the race during a bumpy ride. Since you hold the handlebars almost exactly straight during almost all of your ride, the balls hit the same spot over and over again. The risk is reduced if the bearing balls aren't actually spheres but little cylinders, which are also usually mounted at an angle, both of which spreads the impact energy.
You should frequently check whether your headset is adjusted properly. Stand behind the saddle, lean forward onto the saddle, engage the front brake with one hand, put the index finger of your other hand on the little gap where the top and bottom half of the top bearing join, and push hard against the brake. Your finger should not feel the gap shift at all. If there is the slightest movement you need to readjust it immediately.
If you lift the front wheel and turn the handlebars, and you feel a
point of resistance where the fork appears to "snap" into the forward
position, it's too late. The headset needs to be replaced. Since this
is an expensive proposition, frequent checking is important. Don't
ride with a broken headset, it makes it hard to ride in a straight line
because the normal tiny handlebar movements become impossible.
Adjustment and repair
If you can feel the upper bearing of the headset shifting during the above test, the bearing needs to be adjusted. Some headsets, such as older ones by Mavic, have a lock screw that needs to be loosened first, but normally it's a matter of tightening the nut that contains the upper bearing race against its lock nut. For this you need two appropriate wrenches; don't try to do this with regular household adjustable wrenches!
Unscrew the locknut, tighten the main nut until there is some resistance when turning the handlebars, then tighten the locknut. Tightening the locknut will loosen the main nut slightly, which is why you need to tighten it a bit too much at first. I usually have to repeat this a few times until I am completely satisfied. The handlebars should turn without resistance but pass the finger test, see above.
When I have to adjust my headset, I always use the opportunity to clean and re-grease all parts, both in the upper and lower bearings. A lot of dirt accumulates near the lower bearing, and some might find its way even into a properly sealed bearing.
Sometimes the result is the "indexed" mode where the handlebars seem to snap into the forward position. This is an indication that you waited too long. If you have plain bearing balls, there is one last chance to fix:
Bearing balls are either loose or in a cage (a small ring that holds all bearing balls). Since the indexing effect happens because all the balls simultaneously fall into the pits they have pounded into the races, it helps to change the number of balls. The best approach is to remove the cage if you had one, or put one in if you didn't. If you remove the cage, you must add more bearing balls - add balls until the bottom of the race is completely filled (liberally grease the race to hold the balls in place), then take one back out.
If you didn't have a cage and can't easily find one, it sometimes helps to remove a ball or two and hope that the balls float around enough to avoid alignment with the pits, but never fix a caged bearing by removing the cage without adding more balls. There simply won't be enough of them. Don't add fresh balls, replace all of them because the old balls will have been slightly flattened over time while the new ones are still round. Either way, these fixes are temporary and you should consider a new headset as soon as possible.
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