Why Do ATVs Have Thumb Throttles?

by Matt Powell | Last Updated:  October 22, 2019

If you have ridden dirt bikes AND ATVs then you may have noticed there is one major difference between the two. No I am not talking about ATVs having two extra wheels! ATVs have a thumb throttle instead of the normal twist style throttle that comes equipped on dirt bikes and motorcycles. Other powersports like snowmobiles and jet skis share the use of thumb throttles but today you will learn why ATVs have them.

Engineers that designed the first ATV said thumb throttles don’t require the rider’s entire hand to move and worked better for steering the heavy front end of ATVs.

I never really knew why why ATVs have thumb throttles and dirt bikes and motorcycles like my Yamaha R6 had twist throttles. I did some digging and found the answer and it was actually quite surprising to me. During my research I also found some alternative methods of controlling the throttle different than the thumb style. I scoured forums and other places on the web to try and get the most accurate information I could so I can help you learn why ATVs have thumb throttles and to help you decide if you want to keep that, or try a different style of throttle control.

Did ATVs Always Have Thumb Throttles

I have always wondered if ATVs have always come with thumb throttles and to my surprise, they HAVE NOT always come with thumb throttles. The first ATV, in fact, was not even a four wheeler, but was a 3 wheeler. It was the Sperry-Rand Tricart and it was released in 1967. Most of these didn’t steer like a normal ATV and were a very different design when we think about 3 wheeled ATVs.

As you can see from the picture above, the Sperry Rand Tricart allowed the rider to lounge back and was not very conducive to a thumb throttle anyway. It was not until later that an ATV 3 wheeler was released that happened to have a thumb throttle equipped standard.

Who Started The ATV Thumb Throttle

Also  in 1967, American Honda commissioned one of their engineers, Osamu Takeuchi, to come up with an ATV design that they could sell when their normal motorcycle sales were down. He came up with a 3 wheeled design that had big balloon looking tires and they performed better than any of the other designs at the time. These larger tires gave the new design enough ground clearance to keep the bike from getting damaged while it traversed places that other vehicles could not go.

Honda decided to bring their new 3 wheeled ATV into the market in 1970 and when their new model hit the states, the market suddenly took off until making their US90 or better known as ATC90 (which stood for All Terrain Cycle). The ATC90 sported a WHOPPING 7 horsepower and came equipped with a thumb throttle!

Why Did Honda Use A Thumb Throttle On The ATC90?

Honda engineers did a lot of testing before they decided to put a thumb throttle on their newly designed 3 wheeler and this testing eventually led them to decide that the twist throttle was not the ideal method for throttle control on ATVs. But why?

The answer took a bit of testing but the Honda engineers realized that unlike motorcycles and dirt bikes, the rider does not lean with an ATV when it turns. When a bike or motorcycle turns, because it is on 2 wheels, the rider also leans with the bike. Being that the bike always keeps the same position as the rider in turns, it is ideal to use a twist throttle because you can maintain control throughout the turn. It does not take very much effort or movement of the handlebars to to be able to steer a dirt bike or motorcycle so the engineers had to think of something different for an ATV.

An ATV sits on 3 or 4 wheels and does not lean with the rider as it navigates through turns. When you steer and ATV, you really have to crank the handlebars to the side so you can turn the entire front end in order to steer the bike. The rider then leans off the ATV in order to maintain a good center of gravity to prevent rollovers.

Imagine having to lean to the left, almost off the bike while taking a high speed turn. Your hand would have to maintain its position on the throttle and it would be unnatural and also make it very hard to keep good throttle control.

The engineers also found that it was easier to maintain throttle control with a thumb throttle when turning the very heavy front ends of ATVs. More weight means that you have to use more force to turn the handlebars and using a twist throttle, again, was hard to maintain throttle control. Ever since the Honda ATC90 came with a thumb throttle, ATVs have come standard with them ever since.

Another safety feature that is added in with a thumb throttle is to help prevent rollovers and flipping your ride. Many people put younger riders on ATVs because they have a much easier learning curve since modern ATVs have 4 wheels. Unfortunately 3 wheelers are not produced anymore because they are more prone to rollover by inexperienced riders and have caused many serious injuries and deaths in the years they were manufactured. Thumb throttles help younger or inexperienced riders release easier if they apply too much throttle and pop their wheels up.

When I was first learning to ride my motorcycle I was very inexperienced. My first ride outside of my neighborhood did not go so well. I pulled out of a gas station and twisted the throttle back. Little did I know that the bike I bought had a problem with the throttle sticking open. Well as I was twisting the throttle, I went a little too far and I didn’t realize what was happening.

Before I knew it, the front wheel was in the air. As an inexperienced rider, I didn’t even think to just grab the clutch and hit the rear brake. Instead, my weight shifted back and cause me to twist the throttle even more and before I knew it, I was being drug behind my bike with the throttle wide open. When I finally let go, the bike went tumbling and so did I. Moral of the story is, had it been a thumb throttle in an ATV, my shift in weight would not have caused me to go wide open with the throttle.

Thumb Throttle Fatigue

A lot of ATV riders complain about their thumbs getting very sore when riding and this seems to happen especially during long rides. I too have experienced this sensation when I used to ride back trails in the mountains of Utah for several hours at a time. ATV enthusiasts are very good at finding alternate solutions to problems they have and there are many ways to try to alleviate this soreness and pain.

Try Using An ATV Thumb Throttle Extender

A thumb throttle extender makes your throttle about twice as long as the stock length. The extra length on these extenders allows the rider to to bypass some of the fatigue associated with normal thumb throttle by using leverage to make the throttle easier to press. This option  is great for using your ATV for farming or any other activity where you won’t be doing any aggressive turning or riding because it can cause you to accelerate in an unexpected manner and cause you to lose control.

What Is An ATV Finger Throttle?

Many people have modified their existing throttles or even bought an extra throttle and added it to their current one that allows them to use their index fingers to control their rides. Finger throttle have an advantage of not causing as much fatigue in the finger but it takes some getting used to and really is not ideal. Stunt riders use them a lot to better control their bikes when performing.

You can install a second throttle in position near the index finger and still have your thumb throttle so you can get the best of both worlds. I have not personally tried this but I have seen people that had theirs set up this way. A little soreness in my thumb has never stopped me from having a blast when I ride.

Try A Handy Throttle

A handy throttle is a device that turns your handgrip into a twist style throttle but all it does is slip over your current handlebar. It has a small tab that, when you twist the grip presses the thumb throttle and then you accelerate. It is still a twist style throttle, just without the heavy modification required. I don’t recommend this type because it is still a twist style and I don’t think they are as effective.

Does Anyone Make An Adjustable Thumb Throttle?

A company called Urmosi makes an adjustable thumb throttle that has 6 different settings to accommodate almost any throttle positioning need. I have seen people claim that they get less thumb fatigue using these style throttles because they can customize where the throttle is compared to the ideal position for their thumbs. It has a very innovative design.

This innovative design also comes with a very hefty price of over $200. I myself don’t think that a little thumb soreness is worth spending more than $200 but if you have the extra cash to spare and want to try a high quality product to lessen thumb fatigue, this seems to be the one. Check them out at https://urmosi.com ( this is not an affiliate link but it is a great product if you can afford it).

Convert ATV Thumb Throttle To Twist Throttle

Can you convert an ATV thumb throttle to a twist style throttle? Yes you can, but I don’t recommend that you undertake this modification. Twist style throttle were intentionally NOT put on ATVs and for good reason. Twist throttles on ATVs can be very dangerous if you don’t know what you are doing when riding. They can still be dangerous even if you have all the experience in the world.

Also, don’t expect to find any modern ATVs that come standard with a twist throttle because you probably won’t find one. Manufacturers design these ATVs with safety in mind and don’t want to put any of their customers at unnecessary risk.

Another caveat is that you can only install twist throttle mods on ATVs if they are an older style that does not have fuel injection. If you have extensive ATV or engine/mechanic knowledge, then you probably can but it is totally not worth if you weigh out the pros and cons. I would rather stay safer then to be one of those guys that just HAD to have a twist throttle and got himself hurt.

At the end of the day, using a thumb throttle or thumb throttle modification comes down to rider preference. I have seen people comment that they have tried a twist style throttle on an ATV and had to change it two days later because they just couldn’t make it work. On the other hand, some people claim they have absolutely NO problems with twist style throttles and it is actually what they are used to and prefer. I like to say “to each their own” in this case and will stick to my thumb throttle because I feel it is safer and more comfortable.

As you can see there are many different ways to approach using  a thumb throttle on an ATV. I will let you decide what you want to do since I provided you with all the information you need.

My name is Matt and I am the owner of DirtWheelRider.com. I want to do my best to give you all the information needed in your offroading endeavors.