A lever is an ancient tool that allows one to exert more force on a subject. A brake lever allows the user to, with a light touch, stop a couple hundred pounds of rolling mass to a stop with only modest effort. Position the lever incorrectly and the operator won't be able to take advantage of all that the brake system has to offer. Modern levers and brake calipers do work much better than levers and calipers of years past from both the hoods and drops.
The bicycle to me is a highly visual item. I love the look of a bike that's set up properly. Sure, there are variances, but there's a reason why the components are designed they way they are and that design assumes a certain position. Today, handlebars and controls are designed fairly ergonomically. Handlebar shape is designed to be set in a certain position so it is comfortable in both the drops and the tops. Control levers are shaped to be positioned such that the lever is easily operated in the drops and the hoods offer a comfortable hand position. I cringe when I see bars and levers tilted up and back. Aesthetics. Chances are if the owner feels the need to rotate the whole bar assembly back, their fit is not correct. What that rider needs is likely a taller/and/or shorter bar position, achieved with a different stem, not rotating the bars. But I digress.
Back to the purpose of this post - positioning your levers. When I build a bike for a rider, the first step in my dialing in process is bar positioning. I put the bike on the ground, sit on the seat, put my hands in the drops and set the bar to a spot where it's comfortable in the drops. A position where I can imagine spending time either pedaling into the wind, or descending a tricky downhill that would be comfortable and natural feeling. Tighten the bar clamp.
Time for the levers. Back in the old days, bar shape and brake lever shape were pretty consistent across brands. The way to set brake levers was to hold a straight edge against the bottom of the drop portion of the bar and setting the brake levers so the tips of the lever brushed against the straight edge. Done. Easy. Then bar shape and lever shape changed dramatically. Some bars are slightly curved along the entire bottom edge so a straight edge is no use. These days, I set the levers on the bars loosely with a bit of tension on the clamp so they can be move, but not fall down. Using the drop portion as my main gauge, I put my hands in the drops and put the levers in a position where my pointer finger can naturally and easily reach the lever. I'm a one finger braker. There's really no need to get two fingers on the levers. One does the job great. But that one finger should be at the end of the lever where you have the most, get this, leverage!
With the levers still not tightened down, I check the hood position and make sure that comfortable and easy to operate the levers from the hoods. I may go back and forth a couple of times - drops to hoods, hoods to drops - to make sure the position is dialed.
Levers rough set. Good on top, good on the drop.
Now the tricky part. Chances are good that after doing this, the two levers are probably fairly evenly set up on the bar. But, I'm not perfect and there may be a slight discrepancy. This is where the straight edge comes in. I set a yard stick (meter stick doesn't have quite the proper sound) across the top of the levers with the hoods peeled back. Sighting across the straight edge at the bar, I make sure the levers are parallel with respect to the center section of the bars. I check against logos on the bar, the bar top, and maybe even the stem face plate. When I'm sure the levers are even, I tighten the clamps. Done.
Making sure everything is parallel.
There are other methods I've used, but don't rely on because I've found discrepancies in bars. One is to set the levers according to a scale that is sometimes printed on the back of the bars. However, as is clear in these photos, the scale on this set of bars is off by a good amount.
The scale markings on this bar were way off. When the levers were even and parallel to the bar top, the clamp was at .9 on the right side and essentially zero on the left side.
Another method is to measure from the end of the bar up to the lever body. Again, if the bar is not perfectly symmetrical, you may end up with one lever higher than the other.
And another method requires the use of an expensive tool. I can see this method being used if you need to set the same lever on the same bar on a bunch of bikes, fast, and want them all to be the same. Think race team mechanics setting up a fleet of race bikes. But, you still have to get the levers to the position that is comfortable in the drops and hoods first. A tool won't tell you the levers are comfortable, that's the job of your hands and body.
(What's playing: The Jimi Hendrix Experience Gypsy Eyes)