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My car needs a new front anti-roll bar link (needed rear ones last year). Mechanic says it's probably because of all the local speed humps. I've always been a bit gung-ho about going over them without slowing down too much (though still well within the speed limit). Would it actually make any difference to the suspension if I were to slow down and crawl cautiously over them?
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I wrecked a Vectra and a Mondeo back in my rep car days by doing exactly as you describe ie don't slow from the speed limit at all while going over them. The vectra needed new suspension with 1300 odd miles on the clock. I'd also practiced doing J turns and similar with it as well as a bit of off roading as I hated it so much compared to the Vectra I'd had before.
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Full-width humps, definitely. The shock of hitting one of those too hard - and I realize some of them (like the one outside my house) are practically imperceptible, while some others round here should have signs that read Mountain Goats Only - is horrible and can do nothing but harm to components designed more to cope with high-frequency, low-amplitude shocks.
Cushions are a different matter. My car's wide enough to ride over the side-slopes, so I tend to trundle gently along a whole stretch of them at about 25. The suspension shock is minimal and, whatever HJ suggests, I can't believe it makes a significant difference to tyre wear - the actual time the tyre is in contact with the cushion is tiny.
I should confess that I've had anti-roll bar drop links replaced under warranty, but I understand that these are an acknowledged weakness of Volvos like mine, so probably not purely a consequence of my humping technique. };---)
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I agree with WillDeBeest, with one execption.
When I used to drive a Citroen BX (crumbs, 18 years ago!!) there was no need to slow down for full width humps - it just floated over them. Not sure how a C5 or C6 would take them, with their stiffer set-ups.
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There's such a variation in speed bumps, not only in height, but arc shape (- some don't ramp at all) that I would think caution is definitely advised - in fact I thought that was the point of them?
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>Not sure how a C5 or C6 would take them
Funny you should mention that, BB. I borrowed a C5 VTR last summer from our local Citroen dealer, which happens to be round the corner from the worst stretch of 'umps round 'ere - 15 monsters in the space of about a mile. I won't say I didn't notice them, but nor did I feel the need - as I do in the Volvo - to take the whole stretch in second gear.
Actually, it's a real pity that the C5 is so short of rear legroom for such a long car. In VTR form with the 2.0 HDi engine, I thought it was a wonderfully relaxing car to drive - I loved the way it encouraged me to waft along a country road. But there's not enough room behind a tall driver like me.
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I agree with WillDeBeest with one execption. When I used to drive a Citroen BX (crumbs 18 years ago!!) there was no need to slow down for full width humps - it just floated over them. Not sure how a C5 or C6 would take them with their stiffer set-ups.
Where is the actual evidence that just because your bum doesn't feel the bump as much, that the suspension is suffering any less?
This seems to me like the same argument that says that 30mph in 5th causes less engine wear then 30mph in 3rd.
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If the speed limit is 30mph, or something else lower, one should be able to drive over a hump 1mph below that limit without sustaining ANY damage of any sort to one's car IMO. However this is not how they work. They increase carbon emissions and empty lorries going over them cause a sensational racket for those living near them. A total waste of time and money and not even local residents want them SFAIK
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I'll ignore the question in the text of the original post, but reply to the question in the title. Yes, it's worth slowing down. By doing so you'll reduce the risk of contributing to a fatality.
--
L\'escargot.
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Did you see that episode of Top gear (or was it 5th gear) anyway, they fitted a vibration measuring device to the headrest and concluded that, over the bump they had set up, that 15mph was the most comfortable speed. But it is the angle of the hump that I guess is critical for the suspension. The sharper the angle, the more chance of suspension damage I guess and the more you have to slow down. Of course round where I live, it only stopped the guys who had spent 1000's on their modded cars ( 2 or 3), but not the uninsured, untaxed death brigade who cars are one step away from the scrap heap anyway ( several more!).
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On Traffic Cops you see them pursuing people over one hump after another at high speed. Don't the officers end up sick from all that? And what about the damage to the cars? There are quite a few officers in the BR, maybe they can answer
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Well if the officers suffer then there's always sick leave ;-)
As for the damage to the car, well it's not theirs so I don't think they will be particularly concerned...
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Of course you should slow down. Hitting a bump fast will cause excess wear and damage to the suspension. My wife had her last car for 8 years and went over 7 humps, 4 times a day (28 times) and there was no suspension problems - she slowed down (on my advice) to about 15mph. That' why they are there - to slow you down.
If hitting a wide hump square-on then the anti-roll bar is not loaded - therefore no load or wear on the drop links and very little on the bushes. Pot holes damage drop-links - sudden torsion on the ARB and nasty shock load on the drop-link. Drop links seem to be getting cheaper and nastier - they rarely used to wear out, but the latest VAG ones seem to have very flimsy ball joints.
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My car has quite firm suspension and it seems quite resistant to gross wear from speed bumps. It is rare not to encounter any on the journeys it does in London, often 20 or 30 in a few miles.
I agree with Aprilia that a correct rhythm is required that varies quite a lot with the bumps themselves, which come in all shapes and sizes. The steep trapezoidal wide humps are the worst. The speed required varies from an undiminished speedometer 35 down to about 10mph. You learn the bumps on frequent routes.
Of course the council will sneak in occasionally when you aren't there and change them.
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Of course you should slow down. Hitting a bump fast will cause excess wear and damage to the suspension.
Yeah, I thought it sounded like a bit of a daft question when I posed it, but I distinctly remember a mechanic a few years back saying that speed humps would knacker suspension no matter what, and it didn't make much difference how fast you drove over them. Sounds like he was wrong.
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A local, very large school for the gentry, has an excellent sports club to which I subscribe, although not being one of the aforesaid. There are many speed humps, some v. sharp, to deter the local rally drivers/employees from mincing the pupils. Certain drivers, usually of a blonde disposition, drive at speed and then tailgate those ahead of them. Mechanical sympathy: nil. Intelligence: limited. How they do this without hitting the roof is beyond me: we're talking Fiestas and other small cars, and not generally the usual suspects. On reflection perhaps the larger cars have offspring there, and faculties intact......
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Is it me, or is it a question of common sense?
I drive a small van, and have to deal with a series of humps within a short distance. Three of them can be taken comfortably at 20 MPH, the other at 5 MPH. Obviously, the devious sod that designed them probably knew what he was doing.
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Cushions - Southport - my 2000 Accord slides over them with a barely-appreciable lift if I don't get it perfectly symmetrical.
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I like WillDeBeest's idea of referring to it as your humping technique ;-)
I've also slowed down to around 15mph and haven't had any suspension problems in my car or the work van
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Aprilia says "Of course you should slow down". While accepting that 30 is a limit and not a target, why should one not be able to drive over a bump at the posted limit for the road without destroying one's car? If a lower limit is needed, post it and enforce it with approprate bumps or the famous and ever-popular scameras.
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I don't slow down for the humps, as if you do they will be deemed a success and will continue to be installed.
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i do slow down.. because .. despite what the above post says... i value my car more than i care about what the powers that be think of what i think..
i pay for my car so i look after it ...also if u can feel the bump so can the car..only more
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I don't slow down for the humps as if you do they will be deemed a success and will continue to be installed.
Or alternatively, the Council burghers will think 'Ashok and his like aren't slowing down. Clearly we need even more speed humps.'!
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I knew someone once who led the Argungu Rally in Nigeria for a day or so one year. In the sahelian wastes of northern Nigeria, spectators would gather at places where the rally route crossed more well-travelled roads. They would gather along the rally route cheering, laughing and vigorously signalling the competitors at undiminished speed towards, spotted too late, the horribly high crown of the main road... My friend broke the front axle of his Range Rover as a result of this audience enthusiasm... :o)
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