[Wynn]

Has someone driven a MINI over road humps? I'm curious to know how the car handles going over these-- with its very long wheel base and short overhangs, it seems possible that you might be able to race over them in speeds that would grind the front end off other cars, but I'm uncertain.

For those of you not in the U.S. who might have different vocabulary for such things, I do not mean a "speed bump," which is a short, high bump used to slow traffic in a parking lot; a "road hump" is instead a long (eight feet), shallow hump, like a wide hill in the road, used to keep traffic at slower speeds in a residential neighborhood. If you go over them too quickly, the front end of your car nose dives into the pavement on the other side... but, a bicycle can rip right over them at 25mph and literally almost not notice them, because the bicycle's wheel base is short relative to the length of the hump, and long relative to the length of the bike, which has no overhanging body to dip forward.

Makes me think you might be able to zip over these things in a MINI. Has someone tried?

[carnellm]

They installed a bunch of speed humps in my neighborhood a few months ago. In my MGB I would have to slow down to about 5 MPH to go over them. When they first put them in I went to fast and actually knocked the battery loose!

As for the MINI, I go over at about 20MPH and it has no problems at all. It just kind of goes up and over. I do have the 17" wheels, so that may make some difference too.

Michael

[Dom]

In theory it could go over them quite quickly. But that's never good for the car, and, with sports suspension plus, your back

Dom

[Wynn]

Wow, that's just as I suspected-- how cool! Houston is suffering a plague of road humps, so I'm going to have a blast racing away from police in my MINI over our infested neighborhood streets.

Wheel size should matter very little in this regard, since the outside diameter of the tires is the same regardless of the diameter of the wheels. I'm always amazed that people don't get this, and post concerns about bouncing the wheels into the body of the car because there's less room for the 17s, or wondering about mileage with different sized rims. Silly.

If the outside diameters were different sizes, you'd have to recallibrate the speedometer and odometer when you swapped the wheels.

Speeding over road humps has got me all excited again. Now, if only MINI gets its act together to offer the red interior or beige leather on the S, I'll be ready to buy. I'm currently waiting for such things to be worked out.

[smiffy]

Speed bumps, sleeping polcemen etc etc, no problem at all just dont take them to fast Just be careful you dont catch the front of the car when parking close to low kerbs

[AidenL]

I find they are no problem at all......love flying over them.......mini-roundabouts too !

[carnellm]

Speed humps are fine, roundabouts are extreme fun, but low curbs and such are a pain. I actually have a pretty good sized curb into my driveway, so I have to go in and out perfectly straight and at about 2 mph. Any different and the nose scrapes slightly.

As for the 17" wheels, they don't really change how high your are riding, but they do change the way the car reacts to bumps and such. Primarily because the wheel doesn't give where the tire does. Less tire to give means a slightly stiffer ride - which I love. But, there is a difference. This is also contributed to by the stiffness of the run-flat tires. So, instead of looking for a good bit of shock absorbing in the tires, it must mostly come from the suspension. In my case stiffened sports suspension. So, if anyone should have problems with speed humps it should be me. And I don't!!

Michael

[HarryHBMCC]

Quote:

Originally posted by Wynn
Wheel size should matter very little in this regard, since the outside diameter of the tires is the same regardless of the diameter of the wheels. I'm always amazed that people don't get this, and post concerns about bouncing the wheels into the body of the car because there's less room for the 17s, or wondering about mileage with different sized rims. Silly.

If the outside diameters were different sizes, you'd have to recallibrate the speedometer and odometer when you swapped the wheels.

Actually, they are different! 175/65R15 (495mm) is smaller than 195/55R16 (514mm) for sure; 215/45R17 is even a bit bigger (524mm). I don't know why they did this but it's true...

Harry

[LuckyRVA]

Quote:

Originally posted by Wynn
I'm always amazed that people don't get this, and post concerns about bouncing the wheels into the body of the car because there's less room for the 17s, or wondering about mileage with different sized rims. Silly.

Actually I believe the 17" wheels/tires are wider so there is a possiblity of rubbing the tires along the inside of the wheel well especially if you want to lower your car, I ran into this with one of my past cars. It came stock with 14" wheels/tires but I "upgraded" to 16" wheels and tires. The actual rolling diameter wasn;t much different(actually I believe the 16's were smaller) but they did rub when I hit big bumps b/c the outside of the tire scraped the inside of the fender.

Also, in refernce to your gas mileage and tire size statement, the larger your wheels/tires the worst your gas mileage is going to be. For one they are heavier so it takes more power to get them going from a stop and the result in getting a larger diameter wheel you will have a wider wheel also which creates more wind and road resistance pushing against the tire which hurts your gas mileage too.

[Wynn]

The inertial difference associated with getting larger wheels rolling should have a negligible difference in mileage; once spinning, the larger wheels are at no disadvantage in efficiency. They're just more difficult to spin and stop, so in a lot of stop and go traffic, the differences you're likely to suffer with larger wheels are increased brake wear, and perhaps a measurable deficit in accelleration. But the difference in fuel efficiency is infinitesimal.

[noahe]

Our MCS can go over sleeping policemen, speed bumps, roah humps, or whatever you call them at tremendous speeds, however, due to the taught suspension and the size of the vehicle, they feel particularily harsh, even if they are not accompanied by the horrible grinding sound soggier cars get.

I suspect it's all OK, but I find I take things easier in our MCS when the road is harsh, not because it's fragile, but because you actually notice in this car, when it's takeing a beating.

[LuckyRVA]

Quote:

Originally posted by Wynn
The inertial difference associated with getting larger wheels rolling should have a negligible difference in mileage; once spinning, the larger wheels are at no disadvantage in efficiency.

You forget about wind resistance and friction.Larger hence wider tires will have more of both, especially at higher speeds, it's called rolling resistance. Rolling resistance can have a huge affect on gas mileage at high speeds. Thats why all of the economy cars come with tall gears and skinny tires. ie Toyota Prius and Honda Hybrid.
Rolling resistance actually takes away on average of 4.2% of the power the engine makes, pushing the car against this force results in higher gas mileage and the bigger the surface area; the more resistance.

[Wynn]

I'm fairly certain you're just kidding... but I'll assert anyway that although rolling resistance is not negligible, the difference between the MINI's 16" and 17" wheels' resistance IS negligible, with regard to fuel efficiency.

[Mike Clarke]

Never tried at more than 40 kilometres per hour - at that speed the MINI is fine
If you take them too fast then you had better know where to find the crash detector reset switch

[minky]

had a coutesy car from BMW a MINI ONE....... boy was it fun ripping it through all the sleeping policemans, road bump, humps etc etc. Absolutly no problems wahstsoever, taking 6x8's at 50mph with ease hee hee

then when I get my MINI I drive carefully over them!

[LuckyRVA]

Quote:

Originally posted by Wynn
I'm fairly certain you're just kidding...

Just playing devil's advocate

[KlausR]

I don´t know if the types of bumps are comparable, but in Germany the use bumps of about 10 feet length and approximately 1/2-1 feet height to slow down the traffic when entering a village or small town. I am used to take these at speeds around 35-40 mph with my BMW which is no problem. In the MINIs I have driven (Cooper, Cooper SSP, Cooper S) I could keep up with that speed very well. While other cars don´t stop bouncing and rocking behind the bump the MINI keeps glued to the pavement and continues as if nothing had happened. I believe what´s most important is the right combination of spring and shock absorber setups. Both, the M-tech suspension of my BMW and the SSP in the MINI are programmed for maximized grip on bumpy roads.

Klaus

[erazo]

I would worry about the plastic air dam contacting the pavement upon hitting one of these humps too fast, as well as plowing the other side. Here we are plagued with storm channels on our city streets, creating nasty dips at intersections. My MINI handles them with aplomb, even though that air dam has kissed the pavement a couple of times.