Certain individuals have been heckling me for having top-mount brake levers for quite some time now, and have recently taken this heckling all over the internets. I'm sick of this being a point of discussion, so I will present what I call the "top mount equation." It's a useful tool for determining whether or not you, dear reader, should be riding cross with top mount levers.
Without further ado:
Let's define the variables.
C - City Riding. I know, the first variable has nothing to do with cross. How weak is that?
Yes, a true crosser wouldn't commute on his cross bike. But a true crosser would also have an unlimited budget -- which means none of us are true crossers, huh? Anyway, if you ride in an urban environment with any sort of regularity, you will use the top mount levers. The alternatives are to always, always, always ride on the hoods [edit: or drops], or to smack into something (probably a car) when shit gets crazy and your hands are on the bar tops.
If you ride around the city with your hands on the bar tops regularly and you've never had an incident due to not being able to brake... just wait.
I ride 8 miles a day in traffic on my cross bike so this is a big one for me. C = 5
L - Leverage. Top mount levers pull more cable than road levers, but they also have less mechanical advantage. Usually this doesn't matter, unless...
1) You knocked your wheel out of true and need to open the brake way up so it doesn't rub, because your race starts in 10 minutes.
2) Your brakes are chattering really badly when you squeeze the regular levers and you need to find the spot where you get decent braking but no chattering.
Both of these can be fixed by not having junky or poorly maintained equipment. Yeah, look yourself in the mirror and try to say "I never half-ass anything about my bike on race day, it's always perfect." I sure as heck can't say that, so L = 1. I've had to do both of these things, in my day.
A - Adjustability. Top mount levers, at least mine, have a sweet barrel adjuster that I can adjust quickly, even while riding. I've seen a lot of cross bikes without barrel adjusters, and I don't know about you, but I really like being able to fine-tune my brake travel without using an allen key. I think I tweak my travel to be "just right" before every single race.
Admittedly, I don't know how hard it is to put barrel adjusters on a non-top-mount setup. Feel free to school me in the comments about this. But right now, if I took the top-mounts off, I'd lose the barrel adjusters, which would be a bummer. A = 2.
P - Position. I've noticed this season I almost never use the top-mounts in races, because I'm trying to stay on the hoods more often. But sometimes there's a rough downhill and want to bring my hands closer to my body for better control, and then they are invaluable (i.e. Bedford). Plus, when I'm riding for fun (often in a MTB-ish environment) I like to change hand positions more often since a rigid frame on rocky trails really beats you up.
And the other day I ended up grabbing the bar tops while dismounting around that 180 at Gloucester, and used the lever there too. I probably could've stayed on the hoods but I naturally ended up on the tops, so it was cool that I had brakes there.
Basically, being able to brake in more positions can't be a bad thing. How much this is of use to you depends on how happy you are being restricted to the hoods and drops. For me, P = 2
S - Ah, the first negative factor! S stands for style. Simply put, top-mount levers are as cool as a triple crank. Even if you don't need them, you're letting other people know that you might occasionally use them, which just like the dude with a triple, calls you out as a w-u-s-s.
Side note: Why compact cranks don't suffer from this stigma, I have no idea.
Anyway, you won't see any on the first row of a pro race, and everyone knows that imitating pros gives you an extra 20 watts. And street cred. We all want to look cool, even at something as goofy as cross. It's ok, you can admit it.
For me, well, I am pretty bad at looking cool on a cross bike. Plain kits, pink arm warmers, stutter steps... it's ugly. I have enough other problems that you can tell I'm a fred before you see the top mounts. For me, S = 3
W - Weight. The final, ultimate measure of a bike's value. Top mounts weight in at a whopping 80g for a pair. This is about the same as the weight difference between a super-sweet Dura Ace cassette (160g,$120) and a boring, fat SRAM PG-970 cassette (230g, $55). And you'd be crazy to try to be competitive with a $55 cassette!
I'm a light guy, about 65 kg, so 80 grams is like 0.12% of my body weight. My bike is nothing special, either, probably about 20lb or so. Holy crap, 0.88% of my bike's weight is due to these f'in top mount levers! I gotta get rid of them!!
In case you can't tell, W = 0 for me.
Plugging the numbers in, we get... TM = 5 + 1 + 2 + 2 - 3 - 0 = 7, for me. What's your score?
A score near zero here means that top mounts are pretty neutral to you. In this case, if they're on your bike, leave 'em, but don't go buying and installing them.
A very negative score means you have no use for them and should get rid of them. Take em off your bike and sell them on ebay under a different name, so no one knows you owned them.
A very positive score means you should put some on your bike if they aren't there already.
If you think I missed some terms in this complex equation, tell me!