23
votes
Why is the speed of a motorcycle measured at the front wheel?
There are pros and cons of each, remember you can easily spin or lock up the rear wheel, and in fact the rear wheel may be far less often at the correct speed.
So the decision on this stems from ...
- 18.6k
20
votes
RPMs too high on freeway?
The specs for this vehicle show that it has a 5-speed manual and that 5th gear is OD/Overdrive. According to the performance data here:
The following table from that page lists the speed at 1000 rpm ...
- 12k
13
votes
Accepted
Why is the speed of a motorcycle measured at the front wheel?
Its not a rule of thumb that the Speedometer is connected to the front wheel.
There are many Suzukies and hondas in my country that have the speedometer connected to the rear wheel.
As Rory stated, ...
- 8,946
13
votes
RPMs too high on freeway?
That is the excellent Mazda B3 engine. It will give you 300k service if you treat it nicely. It loves to rev. It does not like to lug.
If you are at high power at low RPM (e.g. an RPM that feels ...
12
votes
Why is the speed of a motorcycle measured at the front wheel?
The front wheel is used in most cases with mechanical speedometers (though there are exceptions) because it's just easier (and probably cheaper) to couple the front wheel to the mechanism.
...
- 581
9
votes
Accepted
Calculating actual speed of vehicle based on wheel size?
The only thing your car can sense is the number of turns of some part of the drive train. In the old days it was a gear right off the transmission, and today it's an electronic sensor in the ...
- 9,316
9
votes
Accepted
How do nonlinear speedometers work?
The speedo will be a standard linear voltmeter.
Vehicle speed sensors are usually attached to either the gearbox output or the differential and produce a pulsed output at a frequency proportional to ...
- 23k
7
votes
Accepted
Why can I not set my Tempomat (cruise-control) to a speed below 30km/h?
Generally a 30 zone implies you are in town, where you are subject to children, pets, footballs, stopping traffic etc.
Cruise control is for long distances at a constant speed where you are not ...
- 18.6k
7
votes
Accepted
Meaning of dashboard "Check Engine Light" on motorbike
That's the check engine light, or CEL - if it lights up, you have a problem with the engine and should stop and investigate it.
If it's blinking, count the number of flashes, as this will indicate a ...
- 28.7k
6
votes
Why is the speed of a motorcycle measured at the front wheel?
All of my competition cars have had speedos, some of which didn't work at all. I have never once been in a race and had time to take my eyes off what was happening around me to look at the dials. ...
- 23.4k
6
votes
How does the speedometer on my dash actually work?
Most speedos in the dash for modern electronic based cars, have a sensor in the output shaft of the transmission. It is a simple reluctor wheel and Hall effect sensor, or a gear driven motor which can ...
- 148k
5
votes
Prius dash board completely off and engine does not shut down
Follow up 10/4/2017
Since the incident reported below, I had the car diagnosed by Toyota and, as expected, they recommend replacing the instrument display unit (5 weeks to get the part and ~$900 in ...
5
votes
Accepted
How does the speedometer on my dash actually work?
Manufacturers deliberately calibrate their speedos incorrectly. They make sure the speedo always reads higher than the actual road speed, and there is a very good legal reason for this.
Speedometers ...
- 18.6k
5
votes
Accepted
Volvo XC90 8V AWD car speed to piston revolution speed ratio changed after repair
Yes, I'd take it back to the shop to see if there is something they missed. While 300 rpm at 60mph is not a huge difference, to me this is about the difference of when a lock up torque converter isn't ...
- 148k
5
votes
Accepted
How is vehicle speed calculated?
If the ECU would calculate speed from RPM, how would it calculate speed when the car is in neutral or during shifting?
The speed usually is derived from the RPM of the output shaft of the ...
- 7,037
4
votes
Accepted
Speedometer on Opel Corsa sometimes not reacting
Often times the speedo cable just needs lubrication. You can do this by disconnecting the speedo cable at the back of the speedometer and dropping some oil down the cable. Happens on Miata's all the ...
- 411
4
votes
Read vehicle speed data in real time
There are two basic approaches, you can tap a speed sensor directly before it reaches the computer, or use OBD II signals (generated by the computer).
Sensors usually generate a voltage, so you have ...
- 1,171
4
votes
Accepted
Prius dash board completely off and engine does not shut down
The symptoms point to a failed Combination Meter. Besides the speedometer, it also controls the power off button and the dashboard lights (except the check engine light). Apparently it can also be ...
- 1,739
4
votes
Accepted
2012 Ford Fiesta S speedometer calibration
UK type approval states that a speedometer may read with upto a 10% error provided that the speed shown is either true or over. A speedometer may not under read when a car is new. Most manufacturers ...
- 23.4k
4
votes
How is vehicle speed calculated?
Somewhere there is a signal that measures rotating speed on the driveline, downstream of the torque converter. It is typically somewhere inside the transmission housing. Because of how a torque ...
- 6,549
3
votes
How is vehicle speed calculated?
The speedometer is generally connected somewhere after the gearbox eg the driveshaft. So in normal circumstances this is directly proportional to the angular velocity of the wheels, depending on the ...
- 1,596
3
votes
Can a speedometer be inaccurate?
Firstly you need to determine whether your speedometer is accurate or not. Ask a friend to drive and hold different speeds in a car with an accurate speedometer and then pace behind that car to see ...
- 15.5k
3
votes
RPMs too high on freeway?
I got 3,000 rpm at 120 km/h on a Hyunday Grand i10, 1.2 lts engine (~5 lts/100km)
- 31
2
votes
Calculating actual speed of vehicle based on wheel size?
To calculate the actual speed you need:
Transmission gear ratios
Final drive ratio
Tire diameter
Engine RPM
[tire diameter (in inches)] * [pi] * [1/(gear ratio * final drive ratio)] / [in/ft] / [ft/...
- 8,433
2
votes
Prius dash board completely off and engine does not shut down
There is a Service Advisory from Toyota on this. I got my combo meter replaced on the 2007 Prius at Toyota's expense. I think there is a time and mileage limit for that. If you are within the limits, ...
- 21
2
votes
Sporadic speedometer, and performance lags when speedometer not engaged
The Vehicle Speed Sensor sends signal to the Instrument Cluster.
You can check pin 2 (blue/white) on the B connector for signal from the VSS. If there is signal you need a new cluster. If not you ...
- 10.7k
2
votes
Prius dash board completely off and engine does not shut down
I took my car in to Toyota and it was a bad combo meter they had to hold my car until the new meter came in because the mileage on the car had to match the new meter. They told me it would be around ...
- 21
2
votes
06 Hyundai Tiburon 2.7l Automatic Speedometer and Odometer Inoperative
Back probed the VSS and the input signal at the instrument cluster.
Yellow = Pin 17 (signal) at the instrument cluster
Green = Pin 3 (signal) at the VSS
Red = Pin 2 (ground) at the VSS
That ...
- 10.7k
2
votes
Why is the speed of a motorcycle measured at the front wheel?
Here's a thought: Most cars have rear-wheel drive. Therefore, in most cars, measuring speed from rotation of the front wheel(s) is more reliable because the front wheels should only be able to spin ...
- 21
2
votes
Why is the speed of a motorcycle measured at the front wheel?
The speedometer is placed in the location that performs adequately well and that costs the manufacturer the least amount of money, and therefore generates the most profit. Period.
- 6,549
Only top scored, non community-wiki answers of a minimum length are eligible