A thumb throttle setup is when you accelerate your bike by pushing your thumb on a spring-loaded lever. But you don’t usually find them on bikes.
Why don’t motorcycles have thumb throttles? Twist throttles are preferred over thumb throttles in motorcycles. The thumb throttle provides lower control and adjustability, thumb pain possibilities, and poor handlebar grip when compared to the twist throttle.
Thumb throttles are common in ATVs, where balancing the vehicle is not an issue. But for two-wheelers like motorcycles, twist throttles work better.
As for how and why, we have discussed in detail below.
First, what are thumb throttles?
The thumb throttle is a throttle setup with a spring-loaded lever that accelerates the bike when you push the lever using the thumb.
If you release your thumb pressure on the lever, the bike decelerates.
In short, push the thumb forward – throttle up. Pull back the thumb and release – throttle down.
The entire acceleration and deceleration of the bike or the motorcycle if installed – is dependent on your thumb movement on this throttle.
With the thumb throttle, there is no need for any wrist movement on the handlebar. You can easily grip the handlebar with your hands and not worry about rotating it to speed up or down.
Put simply, with the thumb throttle – the bike speeds up or slows down depending on your thumb movements on the throttle.
Why motorcycles don’t have thumb throttles
Here are the main reasons why don’t motorcycle has thumb throttle in them:
- Lower control and adjustability
- Loosened grip on the handlebar
- Long ride leads to a sore thumb
- Difficult to maintain throttle position
Let’s discuss each of these reasons briefly in detail.
#1. Lower control and adjustability
Motorcycles require the throttle to be finely adjustable and easy to control.
The entire motorcycle’s speed and balance are dependent on the throttle. The need for finer control gets even higher when you are turning or cornering.
And in that sense, the thumb throttle offers lower control and poor adjustability when compared to the twist throttle.
Controlling the throttle with the entire hand, especially during difficult ride maneuvers, makes more sense than using a thumb throttle and controlling with just a thumb.
#2. Loosened grip on the handlebar
Unlike ATVs, motorcycles are two-wheelers. And they need a better handlebar grip for good balancing.
Using a thumb throttle on motorcycles takes away the thumb grip on the right handlebar. While this might not sound a big issue when you are riding a smooth straight road, the grip becomes significant while riding rough terrains or cornering maneuvers.
With the thumb throttle in place, the rider’s grip on the right handlebar is loosened. In case the tire contacts a heavy stone or object, the rider may lose grip on the handlebar, and hence the balance instantly.
#3. Long ride leads to sore thumb
The thumb throttle requires the rider to push the thumb against a spring-loaded throttle lever.
This might sound fun. But do it for hours. You will for sure get thumb pain that feels like arthritis.
The thumb throttle feels fine for shorter rides. In your backyard practice ride. But the moment you go out for a good ol’ bike ride, your thumb starts to feel sore in no time.
#4. Difficult to maintain throttle position
Motorcycle rider needs to be in fine control of its speed.
And one fine way is to keep a steady throttle position. With the twist throttle on the motorcycle, you can easily have a steady throttle grip. The throttle position stays and maintains the same.
But with the thumb throttle, maintaining a steady throttle position gets difficult.
Rather than controlling the throttle with the entire hand grip, you are controlling the throttle position with just a thumb.
The steadiness in position with one thumb is of course poorer when you compare it to the hand grip on the throttle.
Thumb throttle vs Twist throttle
There are mainly 2 throttle systems in two-wheelers:
- Thumb throttle
- Twist throttle
Thumb throttle, as discussed above, throttles up or down (accelerate/decelerate) depending on your thumb movement on the throttle. The throttle here is in the form of a lever present below the right handlebar.
Twist throttle, on the other hand, throttles up or down (accelerate/decelerate) depending on your wrist movement on the throttle. The throttle here is in the form of a twister on the right handlebar itself.
Thumb throttles are used in ATVs, a few electric bikes, and a few dirt bikes. Their main presence is in ATVs. Apart from that, thumb throttles aren’t really popular.
Twist throttles are used in motorcycles, scooters, dirt bikes, and electric bikes. Twist throttles are the popular throttle type. They are used extensively in almost all two-wheelers.
So, almost all factory-installed motorcycles come with twist throttles.
Any thumb throttles you see on a motorcycle is most definitely aftermarket modification.
For an in-depth guide, here is our post on the differences between thumb throttles and twist throttles.
Can you get a thumb throttle on a motorcycle?
You can install a thumb throttle on a motorcycle.
But manually installing it on a motorcycle with a twist throttle is of course not easy. It requires technical skills. And a good set of mechanical know-how.
You can start by buying a twist throttle from Amazon.
But that’s the easiest part.
Next, you need to disengage the twist throttle from the throttle cables. Remove the twist-throttle parts that you no longer need. Install the thumb throttle on the right handlebar. Connect the throttle cable. Adjust the slack. Test the acceleration with the thumb throttle. Adjust again. Reiterate until it’s working great.
Or. Go to a service center or a mechanic specializing in thumb throttle to install it on your motorcycle.
Bottomline. If you really want a thumb throttle on your motorcycle, you can install it.
Both thumb and twist throttles have their own set of pros and cons. In fact, one can argue it is twist throttle that is better for motorcycles. Not the thumb throttle. But overall, both have their advantages.
You can convert a twist throttle to a thumb throttle. The modification requires lots of expertise and technical know-how. So it is better to go to a service center to convert a twist throttle to a thumb throttle.
Thumb throttles are NOT illegal on bikes. They are just not preferred. But recently there are a good number of thumb throttle bikes in dirt bikes and electronic bikes categories.