In this article I’m going to compare grip shifters vs thumb shifters to explain under which circumstances one outperforms the other.
The birth of index shifting
Both grip shifters and thumb shifters are index shifters. Well configured index shifters make shifting much easier and more accurate than the friction shifters they replaced.

Friction shifters are always single levers. Shifting basically meant guessing how much forward or backward you needed to push the lever to change gears.
With enough practice you could get this dialed in pretty close, but slight tuning after shifting gears to get them to run smoothly was still commonplace.

Shimano introduced the first index shifter in 1986 with the Deore XT SL-M730 thumb shifter. Only the right shifter was indexed. The left one was still a friction shifter.
The right shifter contained a small knob with which to toggle index shifting on or off.
SRAM Grip Shifts
Grip shifters were all the rage back in the 90s. They were originally developed by SRAM and introduced in 1988.

At first grip shifts would be adopted by triathletes on aerobars. But they would soon be featured on mountain bikes as well. And things really took off when they hit the pro MTB circuit, starting in 1990.

In the early nineties, popular names like Greg Herbold and John Tomac would feature the Grip Shifts on their bikes, which meant the rest would follow soon. Including future champions like Tinker Juarez and Missy Giova.
Considering the fact that Shimano dominated the bicycle parts industry it would take a couple of years before SRAM, which was only founded in 1987, could take hold of the market. But it would do so with verve.
In 1995 the entire Cannondale MTB lineup would feature the grip shifters, with the SRAM SRT 800 X-Ray being the top-end model. But in a span of just a couple years they completely disappeared from the top roster of mountain bikes at the turn of the millennium.
This makes them a very vintage option for your periodic-correct 90s mountain bike, but also beg the question why they disappeared in the first place. In the comparison between grip shifters and thumb shifters, were grip shifters really just a fad? Let’s find out.
Grip Shifters vs Thumb Shifters: quality, shifting
Both grip shifters and thumb shifters try to achieve the same, but in a different manner. We can compare the two across a number of key shifting metrics: longevity, shifting performance, aesthetics, and price.
Shifting Performance
There are a number of notable differences between grip shifters vs thumb shifters. The biggest one is that grip shifters enable you to shift to any gear in one continuous motion, whereas thumb shifters will let you shift upwards for a maximum of one gear and downwards of three.
This shifting behavior doesn’t really translate to any benefit in reality. Shifting 4 gears or more is not often used and when performed isn’t any smoother or quicker with a grip shifter than multiple pushes with a thumb shifter.

What can have an impact on especially rougher trails is accidental shifting and mis-shifting with grip shifts.
Operating grip shifts involves resting with your hands on the parts that are also involved in the actual shifting. This means that hard bumps will travel through the bars into your hands, which may cause them to inadvertently rotate and operate the shifter.
Technically with grip shifts you can shift between chainrings. Shifting from one chainring to another is multiple clicks. In my experience you also need to over-shift with grip shifts to move to a bigger chainring.
Also with grip shifts the grips need to stay in their place and not move outwards. If they do and a gap starts to appear between the shifter and the grip, the rubber part that rotates can come off the shifting mechanism. A pair of bar ends on either side will prevent this from happening.
Longevity
Since thumb shifters have protruding levers, some people say that they damage more easily to the point of needing to be replaced. If that’s the case it would be a pretty heavy crash indeed. The clear plastic of X-Ray Grip Shifts are known to crack as well.

All in all the grip shift mechanism are really sturdy. But it’s the rubber twisters and dedicated grips that wear out in the long run. Especially since they need to deal with active rotating movements.
It’s not uncommon to see the tiny knobs of twisters completely gone, as well as worn grips. That means that a good-looking set of vintage grip shifters are more rare.
Also grip shifters usually have the numbers of the gears printed on the shifter itself. Continuous hand movement along the printed area causes it to fade and disappear in the long run as well.
At the end of the day, barring heavy crashes, I would say that thumb shifters are longer lasting than grip shifters.
Price
Obviously price is a key factor, but not nearly as important for vintage mountain bikes that you acquire on the second-hand market.
I feel that comparing the best SRAM Grip Shifts to the best Shimano thumb shifters, in general, you’ll pay far more for the latter. Simply looking at sold listings on Ebay will reveal that a set of XTR shifters will at least cost you two to three times as much. If not more.
Shimano XTR, especially the first generation M900, are highly sought after. This upward trend in price will only increase the price gap between grip shifters and standard thumb shifters.
Rarity

I do have to stress that finding a complete set of grip shifters, which includes the washer that sits between the shifter and shorter grip, and the grips themselves, is a lot harder. Usually a listing only includes the shifter, not these washers and/or grips.

Loose original grips are impossible to find. So if you want to use grip shifts with smaller grip, you can do so by cutting foam grips to the correct size. I’ve done so with ESI Racer’s Edge grips.
Aesthetics
When it comes down to aesthetics between grip shifters and thumb shifters it probably comes down to which one you prefer in terms of shifting performance.
Sachs Power Grip Extreme covers Sram Mud Paw covers
Grip shifters are more unobtrusive than thumb shifters, with less stuff sticking out. That being said, you could get the covers in a variety of colors to further deck out your retro build.
Concluding remarks for grip shifters vs thumb shifters
I can understand why the tenure of grip shifters in the competitive MTB arena was relatively short-lived. They simply are more unreliable than traditional thumb shifters, with more frequent accidental shifting and mis-shifts.

Still, it’s interesting to learn that SRAM reintroduced grip shifters in 2010. With today’s top-end model enabling you to operate an 11-speed rear derailleur. And that can only be because of popular demand.
Either way, grip shifters are very much a fitting companion for a 90s mountain bike. And that unmistakable clicking sound will transport you back to the good ol’ days of early mountain biking.