Why are car steering wheels not 1:1 with their wheels? Like bikes
In: Engineering
Are you referring to the way that a bike’s front wheel is directly locked to the steering bar so that it turns on the same axle, while the steering wheels on a car turn very slightly as you turn a steering wheel in the same way?
If you’ve ever driven a car without power steering – you’ll understand that the wheels are pretty hard to turn. So historically the steering rack was geared to make it physically possible to steer.
With modern power steering systems you could have a more direct ratio, however the steering would become twitchy and it would be more difficult to keep your lane. The gear ratio is a compromise between how much you need to spin the wheel during low speed maneuvers and how smooth and steady the car is at high speeds on relatively straight roads.
Racing cars often have much more direct steering so that the full range of steering is available without having to cross/slide your hands. However this demands a lot of skill and focus.
Edit: It’s probably also a safety requirement that the car is reasonably drivable if the power steering fails.
They have systems in cars as well which also change your steering ratio depending on your speed. So BMW’s active steering will make it quick and closer to 1:1 in parking lots and and loosen up on the highway.
I would not want a 1:1 while doing 80 on the freeway.
The steering in a car is tailored for the comfort and safety of the passengers, and the intended use of the vehicle.
If the wheels turn a lot compared to the movement of the steering wheel, your car will be very twitchy – a small input when driving at speed could cause the car to swerve quite wildly.
If the wheels only turn a small amount compared to the steering wheel then it will be very hard to maneuver your car around tight corners.
So they choose the steering rack to provide a suitable response – a small city car is intended for slower speeds and lots of maneuverability so will get a twitchy steering setup that isn’t as nice on the motorway, while the highway cruising saloon will get something a bit slower and more suitable, and a sports car designed for very high speeds will get something even slower still that means they are terrible to park in a carpark.
This might explain why I’m a bad driver, amongst other reasons.
They’re not?
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