If you’ve never seen this before, watch this NOW.
Honda’s “Cog” ad: If you’ve never seen this before, watch this NOW.
If you’ve never seen this before, watch this NOW.
Recently, I’ve been wondering why in the world we still use drum brakes on our cars.
If you know me, you’ll know that I tend to obsess over a topic until I know everything about it. Witness my entries from a couple of months ago about cars, AWD, and so on. Recently, I’ve been wondering why in the world we still use drum brakes on our cars. I think it’s obvious to everyone that disc brakes are superior in their stopping power; most 4×4 trucks come with 4-wheel disc brakes standard, and so do many performance cars. Motorcycles also use disc brakes exclusively, but not necessarily for the same reason (where would you put a drum on a motorcycle anyway?). So, with that in mind (and with knowledge that even my car has drum brakes in the back), I set out to find the answer to my question.
It was surprisingly hard.
Nobody seems to say WHY drum brakes are used, specifically. There’s much talk of converting drums to discs on all types of cars, there’s discussions of the superiority of disc brakes over drums, and whole volumes of stories about older cars using 4-wheel DRUM brakes and how terrible they were braking under adverse conditions. So, why are we still using them? After an exhaustive evening of web searching, forum prowling, and just general Keith-style research, I’ve come to the conclusion that we still have drum brakes on our cars for two reasons:
2. Parking brakes
Let me deal with these in turn.
Price: it’s an accepted fact that drum brakes are CHEAP. Cheap to manufacture, and cheap to install. This is a free-market economy & all that, so the cheapest effective solution wins. But, you might argue, they’re not THAT much cheaper these days, right? Well, you’re right on that point – the driving issue here isn’t necessarily just the pure price of drums vs. discs… which segways nicely into point 2.
Parking brakes: every car’s got one, right? It’s mandated by some highway safety regulation. A car must have a parking brake. So what does this have to do with the disc vs. drum issue? Everything. Turns out, a parking brake just has to be a manually operated brake system that can function when the engine is off. Now, since modern brakes are all hydraulically assisted, when the power goes out – and the brake pump with it – braking becomes VERY hard. Go ahead, try braking sometime when your engine is off. Not much fun, is it? And what if there’s an emergency and you need to stop the car, but the engine’s off? Enter the parking brake. (Sometimes referred to, logically enough, the “emergency” brake.) Since it needs to be manually operated (i.e. no power assist), and the simplest method of doing that is via a cable attached to a lever or foot pedal, you need a brake system that can be operated by a cable. And the simple fact is, you can’t work disc brakes with a cable (at least not easily – and certainly not CHEAPLY). So you see, the reason we still have drum brakes on the rear wheels of most cars & trucks is because it’s more expensive to put 4 discs on a car vs. 2, and because even if you DID put 4 discs on the car, you need to come up with some way to operate the parking brake manually – and although there are a few different ways of doing it, none of them is simple or cheap (relatively speaking). And since in a car with the engine up front (as in almost every car), under hard braking the front wheels do something like 60-70% of the braking, it seems like an almost logical decision to put the “good” disc brakes up front, and keep the inferior drum brakes in the rear, which not only saves you the cost of putting more discs on the car, but allows you to have a cheap, simple parking brake solution.
Who woulda thunk it?
And don’t even get me started on why big trucks (I’m talking BIG… semi-trailers & buses) use ONLY drum brakes… because I STILL don’t know for sure, but it seems to be price (again), combined with the logistics of operating brakes on air pressure vs. hydraulics. But that’s a topic for another day – or never, since I don’t drive a car with air brakes!
I could chew your ear off with more discussions of drums and their mechanical shortcomings; something about what happens to the brake under hard braking, due to inertial forces, heat, and a whole bunch of other technical mumbo-jumbo… but I won’t, because I hardly understand it myself. I’m just satisfied to know that there is a reason (albeit not a great one, but at least one I can understand) why drums are still on so many cars today.
No, this isn’t some strange perversion of “Disney on Ice,” it’s truly Outlanding (as in, driving around in my Outlander)… on ice!
No, this isn’t some strange perversion of “Disney on Ice,” it’s truly Outlanding… on ice! Yesterday I called up Tom and we went Outlanding together… found some fun, fun trails, and even discovered a deep-space radar & radio tracking facility run by the MIT labs! I’ll post some pictures of it later; they had some huge antennas there! We saw them from a distance while Outlanding, and we decided to “find” them. What a crazy drive!
The best part, though, was when we went up to New Hampshire and drove around on this huge frozen lake. Now, in Massachusetts it’s illegal to do that, but in New Hampshire – well, “live free or die” kinda sums up a lot about New Hampshire, huh? It was SO cool!!! There were big, BIG trucks parked out on the ice where people were ice fishing; I mean like F-250’s… and there were about 10 snowmobiles racing across the ice on this “road” that someone had literally plowed across the ice! Tom had gone there the night before, and drilled down with a 24″ drill bit, and he didn’t strike water, so the ice was AT LEAST that thick… and you only need 12″ for it to be safe to drive on. Needless to say, I wasn’t worried that my measly 3800 lb Outlander would break ice that was supporting 5000+ lb trucks! We had a BLAST… doing donuts, trying to do an axial spin (came close, might have even done it at one point, it’s harder to do than you might think), and racing across the ice at 50 MPH… which FEELS a hell of a lot faster! Whee! The Keithmobile held up wonderfully, and with my crappy (for winter, anyway) All-Season radials, we were slippin’ & slidin’ every which way. It was TOTALLY coooool.
Of course, all of this fun was slightly hampered by the fact that I DO have a cold at the moment; which sucks, I must say. It’s mostly a cough … but it’s got that “tickle” in the back of your throat that makes you want to cough, even though it doesn’t do any good. It’s awful. And my head is a bit stuffed up too, which makes me a little groggy, but with some Dayquil and plenty of water, I’m OK enough. Still, I try to take it easy.
I did get a chance to try some skid tactics on the ice – the perfect place, since there’s nothing to run into, and it’s plenty slippery! Man, you REALLY have to move your hands FAST on the wheel to recover from a skid! But, at least now that I’ve done it a few times, I feel more confident about handling it. The hardest thing to do is not over-steer, but AWD makes it a little easier. The car just “wants” to go in a straight line!
After that adventure, Tom & I stopped at the IHOP up off of 495, past Lowell, which I had wanted to find for some time. I wasn’t feeling well at this point (it had been several hours since I took my Dayquil, and I was due to take some more), but a couple of glasses of cranberry juice and some food helped give me the energy I needed to get home. I gotta give Tom mad props for coming out with me yesterday; getting out of the house and doing some wild & crazy things was exactly what I needed. Aren’t friends great?
After getting home, I swallowed some pills, grabbed my Finding Nemo DVD and headed down to my mom’s house, where I was expected for dinner. After I got there, who should show up but PJ! So we watched Finding Nemo with my mom, and eventually just got some subs from Harry’s Pizza in Northbridge for dinner. We’re so lazy! It was fun, and I ended up staying there pretty late, but I got home and felt OK, took some Nyquil, watched a little TV (to let it get to work) and then went to bed.
This morning I discovered (after waking up at 9am – early for a weekend) that my friend Jim had called yesterday while I was out. Oops! Sorry Jim!
Today is going to be a quiet day; I’ve got to do the grocery shopping for the week, and get my car washed while it’s still “relatively” warm out. After that, I’ve gotta come home and do the bills which have been piling up all week – can’t get behind in them! Ah well…
On a side note, while I was out yesterday, I got 6 voice mails from work, 2 tickets, and a couple of LiveHelp messages. WTF?? Do people think we’re open on Saturdays or something? Do they need to file their court papers on Sunday before the superbowl or something? I just don’t get it. I’ll deal with THEM later…
Well, that’s all for now. As I said, I’ll post some of the pictures I took later on, but for now, I’ve gotta get down to the car wash. My poor car!! It’s so dirty!!
Lots of X’s in SUV names these days, it seems.
Infinity FX35, QX4
GMC Envoy XUV
Lexus RX330, LX470
Can you find the common theme in these SUV names?
Went exploring today in the Outlander (Keithmobile-D) for fun this afternoon. I was looking for a place to watch the Lunar Eclipse from, but there’s so many “no tresspassing” signs these days that it was hard to find anywhere to go.
Current mood: Happy
Currently listening to: The TV in the other room
Went exploring today in the Outlander (Keithmobile-D) for fun this afternoon. I was looking for a place to watch the Lunar Eclipse from, but there’s so many “no tresspassing” signs these days that it was hard to find anywhere to go. I did get down some … interesting … roads, but the Keithmobile-D ROCKS and I had no fear of potholes, dirt roads, or any other obstacles. It was fun, it made me happy.
In the end I think we’ll just stay here and watch the eclipse from our porch. We have a pretty good view of the moon anyway.