On a related note, you might have noticed that one of your dashboard gauges has this red area or a “redline,” if you will.
But why does this redline even exist? And what happens if your gauge reaches this area?
In this blog post, you’ll discover:
- What “RPMs” actually mean
- Why the “redline” is – and why it’s an absolute no-go area
- What a “rev limiter” is – and how it works
Prefer to get this information in podcast form? Listen to the 30 Minute Motorcycling Podcast episode about RPMs and the redline:
What are RPMs?
Essentially, RPMs refer to how fast your engine is running. The more you turn the throttle, the faster the engine runs (especially if you’re in low gear).
But even if you’re standing completely still, the engine still runs a little bit.
For this reason, your motorcycle or scooter has a gauge called a “tachometer” to monitor your RPMs.
The tachometer is sometimes a separate gauge from the speedometer, like the bike below (the tachometer is the one on the right):
Instead, power is delivered through a metal cable that tensions as you squeeze the brake lever - similar to how many motorcycle clutches work.
Although not so much on modern motorcycles, these brakes are highly common on bicycles and e-bikes.
Go Easy on Those RPMs – The Redline Explained
If the engine starts to reach the RPMs at or even near the redline, the engine will run too fast – so fast that you might damage it severely.
The redline depends on the bike – but the same rule of thumb applies – don’t go enter this area.
For a more in-depth explanation about the redline check out this video from the RevZilla YouTube channel:
The best way is to be in the highest possible gear – but to give you an extra safety margin against overrevving the engine, most modern motorcycles have what’s known as a “rev limiter.”
What is a Rev Limiter, and How Does It Work?
But how does it all work?
At a very simple level, if you overrev the engine (either accidentally or deliberately), the rev limiter shuts off one of the parks that control the combustion process, such as:
- Ignition timing
- Spark plugs
- Fuel injectors (for fuel injected motorcycles)