# Given Modern (Smooth) Roads, Are Independent Suspensions Needed? **URL:** \ **Category:** In My Humble Opinion\ **Created:** [August 19, 2015, 2:20pm UTC](https://boards.straightdope.com/t/given-modern-smooth-roads-are-independent-suspensions-needed/728263 "2015-08-19T14:20:10Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![ralph124c](https://avatars.discourse-cdn.com/v4/letter/r/8797f3/32.png) [@ralph124c](https://boards.straightdope.com/u/ralph124c)\ **Post date:** [August 19, 2015, 2:20pm UTC](https://boards.straightdope.com/t/given-modern-smooth-roads-are-independent-suspensions-needed/728263/1 "2015-08-19T14:20:10Z")
Most American cars used live real axles until recently. Even Alfa-Romeo used them-and their cars were certainly well handling. Most USA roads are very smooth, so, could you drive a car with both front and rear live axles, and not notice any differences? Of course, live axles introduce other issues, but given that most people drive for transportation only, would most notice any difference? ---
**Author:** ![lazybratsche](https://avatars.discourse-cdn.com/v4/letter/l/ba8739/32.png) [@lazybratsche](https://boards.straightdope.com/u/lazybratsche)\ **Post date:** [August 19, 2015, 2:30pm UTC](https://boards.straightdope.com/t/given-modern-smooth-roads-are-independent-suspensions-needed/728263/2 "2015-08-19T14:30:45Z")
I dispute the premise! I’ve spent my entire adult life in the Midwest and the Northeast, and only rarely encounter smooth roads. I’ve driven my parents’ 2010ish vintage Mustang, which has a live axle. Handling gets real exciting, real fast, when cornering on a potholed streets or even just taking a slightly bumpy onramp too fast. ---
**Author:** ![Throatwarbler\_Mangrove](https://avatars.discourse-cdn.com/v4/letter/t/8c91f0/32.png) [@Throatwarbler\_Mangrove](https://boards.straightdope.com/u/Throatwarbler_Mangrove)\ **Post date:** [August 19, 2015, 2:32pm UTC](https://boards.straightdope.com/t/given-modern-smooth-roads-are-independent-suspensions-needed/728263/3 "2015-08-19T14:32:20Z")
> [@ralph124c](#): > > Most American cars used live real axles until recently. Even Alfa-Romeo used them-and their cars were certainly well handling. Most USA roads are very smooth, so, could you drive a car with both front and rear live axles, and not notice any differences? Of course, live axles introduce other issues, but given that most people drive for transportation only, would most notice any difference? If you assume perfect roads, you don’t need suspension at all. More realistically, your 3/4t truck based car would need to be sprung very softly to have acceptable ride comfort, which in turn would mean a lot of body lean and wallowing during cornering. For a real world example, I point you to the current iterations of the Ford Expedition and Chevy Tahoe/Suburban/etc. The Ford has IRS while the Chevy has a live axle, neither has any sporting pretensions, and most reviewers find the ride quality of both to be acceptable, some even favoring the Chevy, but the Chevy is at a major disadvantage when it comes to usable space in the third row, because live axles take up a lot of space in the rear. ---
**Author:** ![TriPolar](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/tripolar/32/3008_2.png) [@TriPolar](https://boards.straightdope.com/u/TriPolar)\ **Post date:** [August 19, 2015, 2:38pm UTC](https://boards.straightdope.com/t/given-modern-smooth-roads-are-independent-suspensions-needed/728263/4 "2015-08-19T14:38:01Z")
ralph, you’re not from New England are you? ---
**Author:** ![Amateur\_Barbarian](https://avatars.discourse-cdn.com/v4/letter/a/59ef9b/32.png) [@Amateur\_Barbarian](https://boards.straightdope.com/u/Amateur_Barbarian)\ **Post date:** [August 19, 2015, 2:40pm UTC](https://boards.straightdope.com/t/given-modern-smooth-roads-are-independent-suspensions-needed/728263/5 "2015-08-19T14:40:50Z")
As TM says, if suspension+roads=100%, then perfect roads mean you wouldn’t need any suspension at all. Racing karts have none, for example (or didn’t the last time I looked at the sport) - nearly perfect tracks, a willingness to accept a little bit of ride harshness and a flexible frame are all that’s needed to keep those little monsters glued to the ground. But in anything like the real world (hint to Google and Apple: that means OUTSIDE of your industrial park, tech campus and adjacent 10yo upscale development), letting each wheel respond to the road independently is going to produce better ride and handling characteristics, at the cost of some complexity. (ETA: As TP says. Hey Google, come auto-drive me to my post office and back. It’s only about ten miles. Easy-peasy, right?) ---
**Author:** ![jz78817](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/jz78817/32/1028_2.png) [@jz78817](https://boards.straightdope.com/u/jz78817)\ **Post date:** [August 19, 2015, 2:47pm UTC](https://boards.straightdope.com/t/given-modern-smooth-roads-are-independent-suspensions-needed/728263/6 "2015-08-19T14:47:34Z")
I’ve driven my 2012 Mustang (live rear axle) and a 2015 Mustang (independent rear) back to back, on Michigan roads. the difference is immediately noticeable; any bumps or other perturbations mean the live axle under my car clomps and jiggles around. That’s 200+ lbs of unsprung weight. solid front axles are even more problematic as they can be prone to “death wobble.” ---
**Author:** ![Barkis\_is\_Willin](https://avatars.discourse-cdn.com/v4/letter/b/a183cd/32.png) [@Barkis\_is\_Willin](https://boards.straightdope.com/u/Barkis_is_Willin)\ **Post date:** [August 19, 2015, 2:50pm UTC](https://boards.straightdope.com/t/given-modern-smooth-roads-are-independent-suspensions-needed/728263/7 "2015-08-19T14:50:02Z")
Curious where \*\*ralph124c \*\*is doing his driving. I suspect somewhere in the South? I don’t live in Michigan, but I drive there pretty frequently and smooth roads are like unicorns there. Haven’t done much driving the Northeast but I’m sure it’s the same or worse. But, even with perfect roads you never know what kind of crap might be left on that road. Best to limit the impact to one corner in case you run over an object. ---
**Author:** ![scabpicker](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/scabpicker/32/8268_2.png) [@scabpicker](https://boards.straightdope.com/u/scabpicker)\ **Post date:** [August 19, 2015, 4:01pm UTC](https://boards.straightdope.com/t/given-modern-smooth-roads-are-independent-suspensions-needed/728263/8 "2015-08-19T16:01:29Z")
You don’t really need much of a suspension no matter what the roads, as long as you’re willing to drive slow. If you want to go faster: it’s easier, safer and more comfortable if your wheels can move independently of each other; if you assume that all other vehicle dynamics are the same. ---
**Author:** ![Telemark](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/telemark/32/372_2.png) [@Telemark](https://boards.straightdope.com/u/Telemark)\ **Post date:** [August 19, 2015, 6:14pm UTC](https://boards.straightdope.com/t/given-modern-smooth-roads-are-independent-suspensions-needed/728263/9 "2015-08-19T18:14:06Z")
> [@TriPolar](#): > > ralph, you’re not from New England are you? Actually, he is. I met him at a Boston Dopefest many years ago. ---
**Author:** ![DinoR](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dinor/32/2821_2.png) [@DinoR](https://boards.straightdope.com/u/DinoR)\ **Post date:** [August 19, 2015, 7:32pm UTC](https://boards.straightdope.com/t/given-modern-smooth-roads-are-independent-suspensions-needed/728263/10 "2015-08-19T19:32:33Z")
Michigan’s roads are so smooth their DOT has an online [report a pothole form](http://www.michigan.gov/mdot/0,1607,7-151-9615_30883_30885-69798--,00.html) and toll free number. ---
**Author:** ![2gigch1](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/2gigch1/32/3313_2.png) [@2gigch1](https://boards.straightdope.com/u/2gigch1)\ **Post date:** [August 20, 2015, 1:33am UTC](https://boards.straightdope.com/t/given-modern-smooth-roads-are-independent-suspensions-needed/728263/11 "2015-08-20T01:33:31Z")
I had a [1984 4x4 Toyota Pickup](http://bringatrailer.com/wp-content/uploads/2013/08/1983_Toyota_4x4_front_quarter_resize.jpg) with [solid axles front & rea](http://www.4crawler.com/4x4/CheapTricks/AxleTech/HySteer00.jpg)r. Fun truck. Destroyed my kidneys. _No road was flat enough to make that a comfortable ride._ (Sample photos - sadly I don’t have any photos of my old truck) ---
**Author:** ![Hari\_Seldon](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/hari_seldon/32/5173_2.png) [@Hari\_Seldon](https://boards.straightdope.com/u/Hari_Seldon)\ **Post date:** [August 20, 2015, 1:20pm UTC](https://boards.straightdope.com/t/given-modern-smooth-roads-are-independent-suspensions-needed/728263/12 "2015-08-20T13:20:09Z")
Come to Montreal. I defy you to find a smooth road. And if that weren’t enough, the authorities litter the residential streets with speed bumps. So do shopping centers. Driving between here and Boston or NY is no prize either. ---
**Author:** ![Really\_Not\_All\_That\_Bright](https://avatars.discourse-cdn.com/v4/letter/r/e8c25b/32.png) [@Really\_Not\_All\_That\_Bright](https://boards.straightdope.com/u/Really_Not_All_That_Bright)\ **Post date:** [August 20, 2015, 1:37pm UTC](https://boards.straightdope.com/t/given-modern-smooth-roads-are-independent-suspensions-needed/728263/13 "2015-08-20T13:37:36Z")
> [@ralph124c](#): > > Most American cars used live real axles until recently. Even Alfa-Romeo used them-and their cars were certainly well handling. Alfas haven’t used a live axle since about 1977. ---
**Author:** ![TriPolar](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/tripolar/32/3008_2.png) [@TriPolar](https://boards.straightdope.com/u/TriPolar)\ **Post date:** [August 20, 2015, 1:44pm UTC](https://boards.straightdope.com/t/given-modern-smooth-roads-are-independent-suspensions-needed/728263/14 "2015-08-20T13:44:22Z")
> [@Telemark](#): > > Actually, he is. I met him at a Boston Dopefest many years ago. Well I’d really like to see these smooth roads he’s been driving on. ---
**Author:** ![lazybratsche](https://avatars.discourse-cdn.com/v4/letter/l/ba8739/32.png) [@lazybratsche](https://boards.straightdope.com/u/lazybratsche)\ **Post date:** [August 20, 2015, 2:24pm UTC](https://boards.straightdope.com/t/given-modern-smooth-roads-are-independent-suspensions-needed/728263/15 "2015-08-20T14:24:11Z")
Ooh, I have one just a block away from me! It was repaved three or four months ago, after three years of water main overhauls left it damn near impassible. Judging by the other roads around here that have been recently repaved, nobody will be able to call it “smooth” after one hard winter, or a handful of normal winters. ---
**Author:** ![Voyager](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/voyager/32/133_2.png) [@Voyager](https://boards.straightdope.com/u/Voyager)\ **Post date:** [August 20, 2015, 7:42pm UTC](https://boards.straightdope.com/t/given-modern-smooth-roads-are-independent-suspensions-needed/728263/16 "2015-08-20T19:42:57Z")
San Jose is in the top 10 of crappy roads, and that is without winter weather. There is something like an $80 billion backlog of road infrastructure repair in California. So smooth roads? Ha! ---
**Author:** ![Amateur\_Barbarian](https://avatars.discourse-cdn.com/v4/letter/a/59ef9b/32.png) [@Amateur\_Barbarian](https://boards.straightdope.com/u/Amateur_Barbarian)\ **Post date:** [August 20, 2015, 7:55pm UTC](https://boards.straightdope.com/t/given-modern-smooth-roads-are-independent-suspensions-needed/728263/17 "2015-08-20T19:55:46Z")
> [@Voyager](#): > > San Jose is in the top 10 of crappy roads, and that is without winter weather. There is something like an $80 billion backlog of road infrastructure repair in California. > > So smooth roads? Ha! It’s not about just smooth roads. (At least, my side comments weren’t.) If you’ve never driven in the northeast, you will have trouble imagining just how _B_A_D_ roads can get, especially in denser areas. California had the luxury of building out most of its road infrastructure in the modern era and following stringent engineering and traffic guidance rules. The very worst roads I can recall from California are better than most of the “good” roads here. Many curves and dips. No curbs. Sharp turns in unexpected locations. Many, many “jogs” where you sort of have to do a side-shuffle to stay on the same road, or vague “narrow-X” intersections where you have traffic doing the side-shuffle in two simultaneous directions. Highway onramps that go from surface street to sharp corner to 100-foot acceleration strip to highway speed, with an all but blind entry. Small bridges in the center of a curve that require a sort of S-curve correction to cross. Traffic lights set so high you can’t see them from the limit line. Roads that change names every half mile or so, for dozens and dozens of miles. I just described MOST of the roads in Connecticut and western Massachusetts. Add in that there’s some sort of peculiar arrangement so that most times, by the time you see your destination, you’ve passed its entrance. You just have to know/learn that the turn-in is the one on the blind corner, before you get around the corner and see the store or plaza or whatever. Few if any such are marked. While San Joe and other California cities might be showing their wear and tear, nearly all roads there are wide, straight, sensibly routed, allow for driving and nav judgment without last-minute panic moves, and in general are about ten times easier to drive. So GoogPle self-drivers that can work in not just that “clean” environment but in even more artificial zones like tech campuses, industrial parks and newer subdivisions and commercial areas… big deal. Ray Charles could do as well. My drive to the post office here is one any reasonably competent human driver could make, but involves all of the above hazards. I would truly LOVE to see a self-driver make it there and back without the cheat of special programming. There’s at least two places an SDC would either go off the road or go into some kind of safety shutdown. ---
**Author:** ![GrumpyBunny](https://avatars.discourse-cdn.com/v4/letter/g/bc8723/32.png) [@GrumpyBunny](https://boards.straightdope.com/u/GrumpyBunny)\ **Post date:** [August 21, 2015, 3:00am UTC](https://boards.straightdope.com/t/given-modern-smooth-roads-are-independent-suspensions-needed/728263/18 "2015-08-21T03:00:44Z")
> [@TriPolar](#): > > ralph, you’re not from New England are you? I came in to say this. Haven’t driven on a smooth road since I moved here. ---
**Author:** ![Fool\_in\_the\_Rain](https://avatars.discourse-cdn.com/v4/letter/f/8491ac/32.png) [@Fool\_in\_the\_Rain](https://boards.straightdope.com/u/Fool_in_the_Rain)\ **Post date:** [August 21, 2015, 6:07pm UTC](https://boards.straightdope.com/t/given-modern-smooth-roads-are-independent-suspensions-needed/728263/19 "2015-08-21T18:07:17Z")
> [@Telemark](#): > > Actually, he is. I met him at a Boston Dopefest many years ago. Then how can he be asking this question?? I haven’t met a smooth road New England hasn’t ruined… ---
**Author:** ![Spud](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/spud/32/347_2.png) [@Spud](https://boards.straightdope.com/u/Spud)\ **Post date:** [August 21, 2015, 7:19pm UTC](https://boards.straightdope.com/t/given-modern-smooth-roads-are-independent-suspensions-needed/728263/20 "2015-08-21T19:19:46Z")
> [@lazybratsche](#): > > I’ve driven my parents’ 2010ish vintage Mustang, which has a live axle. Handling gets real exciting, real fast, when cornering on a potholed streets or even just taking a slightly bumpy onramp too fast. A 2010 generation is “vintage”… just kill this old man now. I have a 2006 GT convertible, and I still would not consider it vintage… I added a front strut bar to firm things up, but I’ve never had a handling issue. That said I’ve heard great things about the 2015 with the independent suspension. [Next page](https://boards.straightdope.com/t/given-modern-smooth-roads-are-independent-suspensions-needed/728263.md?page=2)