How should be horizontal and vertical angles of the levers be measured to ensure both left and right levers are mounted in identical positions? Unfortunately, the handlebars have no markings to assist with positioning of the levers.

Lay a straightedge across the top, then very carefully look across the front, changing your viewing angle so you are looking at both the straightedge and your bars. When the sliver of light between them is the same, so are your levers.

The other is using a bubble level. Prop your bike until the bars are level, then put the level on the top of the levers.

Mount one lever where you like it. Then mount the second loosely and slide it close to even by eye. Lay a broom stick or similar across both and lower your head until you can line up the broomstick with the tops of the bar. Any error will be obvious. Adjust, recheck, and tighten.

BTW- if you just mount these by eye and can't feel a difference when riding that's close enough. It's not like your arms are identical anyway.

Crap, that explains a lot. I thought it was my bars causing me to pull left...

If handlebar makers are going to put markings near the stem, as in the attached photo, they could put them on the bends for quick lever placement. I have no clue what use those clamp area markings are good for, by the way.



I ride with traditional bend drop bars and usually start from scratch - mount the levers, snug 'em up a bit, put the bars on the floor and get the lever tips to touch the floor. Then I mark the clamp band positions with a Sharpie and ride around for awhile with reference points if I need to make adjustments. No need to carry a broom handle.

They help you center the bars in the stem clamp and give you an index to set the angle of the drops and hooks. There are bars with index marks on the bends to assist brake lever/brifter placement

Uhhh, you don't carry the broom handle, it stays in the shop. Frankly, the broom handle/yardstick method of equalizing lever placement is a lot more convenient than standing the bike on it's head to use the floor for the same purpose.

Adjusting angle is purely by feel, I don't see how those + 0 - lines help. You ride around and make adjustments.

What I meant by "starting from scratch" was handlebars off the bike.

Most mechanics attach brake levers after the bar is on the bike. Part of the reason is habit dating to when this was the only way it could be done. The other reason is the bike or stem holds the bar freeing the hands for the job. Of course ypou could always hold the bar another way, but why do it the hard way.

The other method. (from Park Tool website)

I'm going to try the broom handle thing next, just for grins.

What I usually do is mount one lever where I want it. I then run a piece of tape up the inside curve of the bar bar from the bar end to the clamp and cut it to length. I then use the same piece of tape on the other side and put the clamp where the tape ends. It's generally close enough for my needs.

I used to eyeball it and generally close enough. Sometimes I'd be bugged by a mm of difference, so would just take the tape off one side and adjust as necessary and re-wrap the tape. A few minutes at the most, once per bike.

For those who mount the levers before putting the bar into the stem, there's an easy accurate way that works most of the time.

Mount the levers and tighten one. Place the bar on a table and, holding the levers out, roll it forward until the tips of the levers touch. You want 4 point contact, like a table that doesn't wobble.

This method doesn't work as well if the levers extend below the line from the bottom of the drops, but otherwise it's quick and easy.

I like the 4 points method suggested by a few people here. One could also use a pane of glass or something, attach some things to create space for the stem, and do it with the handlebars already installed.

the rotation about the bar affects your grip and wrist angle.
before you tape up, play with different angles. I prefer some inboard cant.

That's how I do it, but just eyeball the gap (or overlap).
I do it before taping. I usually do a couple short rides without bar tape, and bring tools for adjusting things when setting up a new bike.

I definitely like the 'mount one lever to comfort, then match the other by eye/feel' method. It takes a little longer sometimes but, after a couple test rides to get the placement just right, I feel like I've got the placement just right for myself.

Since arms aren't perfectly symmetric, even with the broomstick I would have to make micro adjustments.

I agree. I use the broomstick method when setting up other peoples bicycles, because it's a very quick way to eyeball symmetry reasonably closely. As far as I'm concerned any effort to get it more precise reflects a degree of obsessiveness that seems to have become trendy.

As I said in post No.3 our arms aren't that perfectly matched anyway.

lol i did it.

Does this qualify you for my "you might be OCD if...." thread?