Sim racing shift lights with SimHub
Last updated · SimHub 9.11.22
Shift lights are a row of LEDs that fill as engine revs rise and flash at the point you should change gear. SimHub can drive them on an Arduino strip, on a supported wheel with built-in LEDs, or on screen as part of a dashboard. The setting that decides whether they work is the RPM range: a bar spanning 0–100% of the rev range is lit constantly and tells you nothing, while one spanning roughly the top 60% is dark when you are cruising and informative when you are not. Calibration is per car, because redlines differ.
Shift lights are the most useful piece of sim racing hardware relative to their cost, because they let you change gear without looking away from the corner. They are also the easiest to configure badly.
What they are actually for
Not to tell you the revs — a tachometer does that, and you have one. Shift lights exist to tell you when to change gear without looking.
That distinction drives every configuration decision. A display you have to read and interpret has failed at the job; one you perceive in peripheral vision while looking at the braking point has succeeded. Everything below follows from that.
- Peripheral vision is colour-blind and motion-sensitive. That is why the redline signal is a flash rather than a colour change — you will notice movement at the edge of vision long before you notice red.
- Position is read faster than quantity. You know how full the bar is without counting.
- Consistency matters more than precision. A bar that means the same thing in every car is more useful than one calibrated perfectly for one car and wrongly for the rest.
Where shift lights can live
| Option | What it takes | Trade-off |
|---|---|---|
| On a wheel with built-in LEDs | Nothing — SimHub drives many wheels natively | Free if you own one. Fixed LED count and position. |
| A DIY Arduino strip | An Arduino, LEDs, a supply, an afternoon | Cheapest and most flexible. You choose count, spacing and mounting. |
| A made unit | Money | No soldering, and it is mounted properly. Less flexible about where it goes. |
| On screen, in a dashboard | Nothing | Free, but it is on a screen — which is the thing you were trying to look away from. |
Check the device list before buying anything: many wheels already have LEDs SimHub can drive, and people regularly buy a separate bar for a wheel that already had one.
This is worth doing before you spend anything. A natively supported wheel appears under Devices with its own LEDs tab — brightness, static button lighting presets, and separate profiles for button lighting and for telemetry LEDs, which is what shift lights are:
Note the Import profile and Profiles manager links beside each one: LED profiles are shareable files, so a good configuration for a given wheel can be handed round rather than rebuilt. The LED editor covers what is inside them.
The setting that decides everything: the RPM range
This is where most shift light setups go wrong, and it is one number at each end.
The instinct is to have the bar span the whole rev range — nothing at idle, full at the limiter. That produces a bar which is partly lit almost all the time, and a display that is always on carries no information.
Instead, start the bar where shift decisions begin. Something like 38% to 98% of the rev range works well across a wide variety of cars:
- Below the floor, the bar is dark. Cruising, part throttle, low gear pull-away — nothing. The bar being lit at all now means something.
- Across the range, it fills. The whole physical length is spent on the part of the rev range you actually make decisions in, which is what gives you resolution where it counts.
- Just short of the ceiling, it flashes. Ending slightly before the true limiter leaves room for the redline signal to be a distinct event rather than the end of a gradual fill.
Percent or absolute RPM? Percent, almost always. A percentage adapts to whatever car you are in, so one configuration works everywhere. Absolute RPM is right only if you drive one car exclusively, or if you want a bar calibrated to a specific engine's power band rather than to its rev limit.
Per-car calibration
Percent-based configuration handles most of the variation, but not all of it. Two cars with the same rev limit can want different shift points, because the useful shift point is where power falls off, not where the limiter is.
- A turbo engine may make nothing above a point well short of the limiter — shifting at the redline is slower than shifting early.
- A naturally aspirated race engine often pulls right to the limiter, and shifting early costs time.
- An electric car has no meaningful redline at all, and shift lights are close to meaningless.
SimHub remembers configuration per car, so you can calibrate the cars you drive most and leave a sensible default for the rest. The practical method: drive one car, note where power stops arriving, and set the flash point there rather than at the limiter.
If you only ever adjust one thing per car, adjust the top of the range. The bottom rarely needs moving.
Blink patterns
The redline signal has one job: to be impossible to miss while you are looking somewhere else.
- Flash rather than colour-change. Motion is what peripheral vision detects. A bar going solid red is far less noticeable than the same bar blinking.
- Fast enough to read as urgent. A slow blink reads as a warning light; a fast one reads as now.
- All LEDs, not some. A partial flash competes with the fill you were already reading.
- One pattern, everywhere. Consistency is the entire value — a signal that means different things in different cars is worse than no signal.
Some setups use a distinct colour for the flash — blue and white are both common, because neither appears in the green-to-red gradient below it and so cannot be confused with the bar filling.
The mistakes that make shift lights useless
| Mistake | Why it ruins them | Fix |
|---|---|---|
| Range set to 0–100% | The bar is always partly lit, so it carries no information | Raise the floor to around 38% |
| Fill direction reversed | You read it backwards under pressure, which is worse than not having it | Tick right-to-left mirroring — it depends on which way you mounted the strip |
| Flash at the limiter, not the shift point | You are already too late when it fires | Set the flash where power falls off |
| Too bright | It is distracting at night and washes out your night vision | Set brightness for your usual conditions |
| Mounted out of peripheral vision | You have to look at it, which defeats the purpose | Put it in line with the top of the wheel, in your sightline to the track |
| Different behaviour in every car | You cannot build the reflex | Use percent, and keep one blink pattern everywhere |
Reversed fill is the most common single complaint. It is one setting — the right-to-left mirroring option — and it exists precisely because there is no correct default. Which way the bar fills depends on which end of the strip you wired, and you cannot know that until you look at it running.
Building or buying
A DIY shift light bar is a good first electronics project. A Nano, a strip of WS2812b LEDs, a 5V supply and a bracket — the configuration is the recipe in this page and none of it is secret. The RGB LED guide has the wiring.
Made units exist from several manufacturers, and a number of wheels have LEDs built in already — check the device list first, because you may already own the hardware.
We make one too: our Rev Gauge is a 16-LED bar for Fanatec bases and desk mounting. It is one option among several, and the reason to mention it here at all is that the worked configuration in the RGB LED guide is its actual setup, which makes it a useful reference point whether you buy it or copy it.
Common questions
What RPM range should shift lights cover?
Not the full range. Something like 38% to 98% works well — below the floor the bar stays dark so that it being lit at all means something, and stopping short of the limiter leaves room for the redline flash to be a distinct event rather than the end of a gradual fill.
Should shift lights use RPM percent or absolute RPM?
Percent, almost always, because it adapts to whatever car you are in and one configuration works everywhere. Absolute RPM only makes sense if you drive one car exclusively or want the bar calibrated to a specific engine's power band.
My shift lights fill from the wrong side.
Tick the right-to-left mirroring option. There is no correct default — which way the bar fills depends on which end of the LED strip you wired, so it is a setting rather than a bug.
Where should the shift light flash?
At the point power falls off, not at the limiter. In a turbo engine those can be a long way apart, and flashing at the limiter means the signal arrives after the moment you should have shifted. SimHub remembers configuration per car, so calibrate the cars you drive most.
Do I need shift lights if my dashboard already has a rev bar?
It depends where you look. An on-screen rev bar requires you to look at the screen showing it, which is the thing shift lights exist to avoid. A physical bar in your sightline to the track can be read in peripheral vision while you are looking at the braking point.
Does my wheel already have shift lights?
Quite possibly — many wheels have built-in LEDs SimHub can drive natively. Check the device picker before buying anything separate; people regularly buy a bar for a wheel that already had one.
Why flash rather than turn red?
Peripheral vision detects motion far better than colour. A bar going solid red is much less noticeable at the edge of your vision than the same bar blinking, and being noticed without being looked at is the entire job.
Sources
Related guides
SimHub is developed independently by Wotever and is not affiliated with oesimracing. This page was checked against SimHub 9.11.22 on 4 August 2026; where the interface has moved on since, the version stamp tells you how far. More on what SimHub is and what it costs.