Why do manufacturers use that blasted thumb throttle lever on an ATV? Why not a grip throttle control like a motorcycle?

Lawyers & Lawsuits!

I've always wondered why they use a grip throttle on motorcycles instead of a (superior ) thumb lever like they use on ATVs and snow machines.

Control. If you ride/work in steep/rough enough country, at some point you'll be using your grip on the handle to keep your seat. That little thumb lever keeps you from giving it more umph when all you're trying to do is hang on...that unintended umph might be the difference between being on the trail and a couple 100 feet down the side of the mountain.

This ^^^^^ from my own personal prospective as well.A grip throttle would = an elevated cast most assuredly.

Makes sense but we don't use them where we elk hunt. You would have to pack it in and they are frowned upon. Mine gets used more to plow snow than anything.

I've ridden race bikes (3 wheelers) with the twist throttle and I hated it. Almost killed myself riding a whooped out trail and lost control of it after hitting some major bumpage. Never again!

Snowmachines have the same throttle as atv's and the big thing these days is to turn them around so your squeezing the throttle with your fingers instead of thumb. Haven't tried it yet but might next week.

That might help. Been using an ATV with a GPS mounted to do long survey lines collecting data at work to create digital terrain models. After a few days the old thumb gets pretty tired.

No speed involved at 5 MPH.

I agree ... back in my ATV days I installed Motion Pro twist throttles on all my quads. They just seemed effortless and with some experience they aren't any more dangerous than the thumb throttle. I have moved on to side x sides and the foot controls are even better. He11, I'm to the point now where I almost always have my 8yr old son with me and I let him take the wheel while I kick back, relax, and enjoy a cold one! We are both happy in the end.

Throttles need to be put on the left side. Leaves the right hand free, to pistol up the coyotes you're chousin'......

Or for sidehilling a sled. Its as easy as: Gold Finger

There is nothing quite as funny as someone not used to dual throttles grabbing the lefty throttle when they are going for the brake.

A friend has an old Yamaha atv with a terrible thumb lever. It's located too far out from the bar and you have to stretch way out to reach it. The thumb gets really sore in a short time.

There is an aftermarket throttle extender so you can use more of your hand instead of just your thumb.

A fired 12 gauge shell works good for a temp throttle extender.

Thumb levers? About 15 years ago, I needed to cross a swampy area to recover an elk. My ATV is only 2wd. I was in about a foot of water when the front tires came up against a submerged log and stopped me dead. I was standing on the pedals rocking it to get some traction to back up. The rears were turning nicely when one of them caught and I shot backwards. Since I was standing, it threw me forward over the bars and my waist was pressing down on my hand so I couldn't release the throttle. I probably accelerated for 10 yds and was getting up a good head of steam before I could get my hand out from under me to stop. My partner who watched it all thought it was a lot funnier than I did.

I've got one of those throttle extenders on my Foreman and you can bend it to where it feels comfortable, I like it and my thumb never gets sore.

I plow with my ATV and my glove got fouled on the throttle extension lever extension. I got to the end of a neighbor's driveway and the more I squeezed the front brake the faster I went. I yanked my right hand off of the grip and help it up like a bronc rider in a rodeo! The extension levers are great for long rides or if you have carpal tunnel in your right hand.
The reason for levers VS twist grips is on a bike your lean to turn and on ATVs and snowmobiles you steer with the Handle bar.
A friend of mine that has been riding bikes for over 45 years had a time getting used to riding an ATV.