Effetto Mariposa Giustaforza 2-16 Pro torque wrench review by Josh Ross

There are cheaper torque wrenches that can do the job just fine but this is an option that will likely last a lifetime and is an incredible joy to use

Design doesn't show grease and stays looking good
Short length promotes correct grip
Loud click and 3-degrees free-movement is hard to miss when torque is reached
Lazer-etched marking will never rub off

Doesn’t include a quality hard case
Only measures torque in one direction

Every fastener on your bike has a maximum torque value associated with it. Get those numbers wrong and you risk cracking an expensive piece of carbon fibre or stripping a bolt. The only way to ensure you hit the number you need is with a quality torque wrench.

We recently put together our list of the best torque wrenches. A buyers guide like that means the opportunity to test lots of options against each other at the same time. Some don't make it to the list at all but there are options such as the Giustaforza 2-16 Pro that really stand out. Over the last year, long before the current buyers guide, this wrench from Effetto Mariposa has been our go-to option.

It's not for everyone though so keep reading to see our thoughts on this option. We've spent a lot of time with it and now we are ready to discuss why we like it but also why you might decide to make a different choice.

Design and aesthetics

There are a few different variations of torque wrenches offered by Effetto Mariposa. They vary not only in torque ranges but also in types of heads offered and how they come packaged. Choose the 2-16 Pro Deluxe and you'll be getting a torque range that covers just about everything you'd regularly need to adjust on a bike. You'll also be getting the wrench with a tool roll and a collection of bits.

Open the box and you'll find a two-part, hard plastic case. Pull it apart and inside is a tightly rolled vinyl roll secured with a red strap and Velcro. Keep unwrapping your new wrench and you'll find that the roll has a flap at the top and space inside for a plastic holder with 2, 2.5, 3, 4, 5, and 6mm hex bits, T10, T15, T20, and T30 torx bits, as well as a slotted and a Phillips head screwdriver. Above that, there are four 100mm extensions including a 4mm and 5mm hex, a T25, and one more that will accept the bits.

The bits themselves don't look to be anything special but the specs say otherwise. The steel used is high-quality S2 tool steel. It's a harder steel - in this case specifically called out as being HRC (Hardness Rockwell C) 62, that doesn't show up on lower quality tools. Less precision bits will use Chromium Vanadium Steel and generally be a softer material. The point of all this is that a harder steel is less likely to lead to rounded bits over time.

The lower section of the aluminium body has a knurled section signifying the hand grip and a window with laser-etched markings for the torque settings. Whole numbers are on the left and half number marks are on the right. That attention to detail continues when looking at the actual wrench. To see the wrench, you'll pull it out of a unique slot to the left of the roll. There is no plastic and the main body is a single piece of red anodized aluminium. The upper section has branding and the model name is laser-etched into the aluminium. Opposite the branding is a unique number that changes for every wrench.

The moving parts of the wrench include the adjustment cylinder at the bottom. The bottom of the adjuster also has a knurled grip at the bottom and there's a hard stop that keeps the adjustment from coming out of the body. The very end of the wrench includes a 4mm hex opening that makes it possible to use a wrench in case you need it to get all the way to the max torque.

At the other side is a ratcheting head with a 1/4-inch square driver. Both versions of the wrench include an adapter to convert the driver so that it can accept standard hex bits. In the centre of the head is a silver release button and surrounding that is a knurled dial that reverses the drive direction of the ratcheting head. Keep in mind that while you can reverse drive direction, you shouldn't. Loosening a bolt with a torque wrench risks breaking the calibration and there's no reverse torque measurement.

On the subject of calibration, Effetto Mariposa checks each wrench they send out. The guarantee is that the tolerance will be +-4% for 5,000 clicks. It also offers a calibration-renewal service. The tool comes from Italy but Effetto Mariposa is a Swiss company and it's in Lugano Switzerland that you can send the wrench back for a new calibration. The price is 50 CHF and that buys you a new calibration certificate for another 5000 clicks.


The first thing you'll notice when you touch the Effetto Mariposa Giustaforza 2-16 Pro torque wrench is its heft. The company proudly claims that the aluminium body keeps the weight down below 200g and they are correct. My scale puts it at 188g without the adapter for hex bits and that's similar to other wrenches I have on hand but this one is smaller. The effect is that there's a solidity to it that feels better in the hand than those other wrenches.

The length is purposeful, too. The details on the product page list the length as 170mm but that includes the length of the adjustment as well. The actual tool, from the tip to the end of the main body, is about 150mm and is noticeably shorter than other options out there. The most obvious result is a reduction of leverage that better matches what's necessary for the torque ranges this covers. The other advantage is that it reduces the space for your hand.

Torque wrenches are only accurate if you hold them in the right place. It's common for people to move their hand around on a torque wrench depending on how nervous they might be about a particular bolt. With such a short shaft, there's really only one comfortable place to hold it. Grab the knurled grip in the aluminium and you've got your hand set just right for perfect measurement.

Start using the wrench, and the first thing you'll need to do is set your desired torque. There's a line that's visible through the window in the body. Rotate the unfinished metal adjuster and that line moves up as the spring compresses inside. The more common system requires pulling back on the adjuster and rotating against the spring weight. This is a more convenient system that's faster and you can see it move from line to line, representing .5Nm per line, without needing to count turns or look at the back of the tool. The system also keeps the spring protected from dust and grime and even after a year of use, the built-up grease is hard to see on the finish. For those that care about such things, this is a tool that will continue to look good for a long time.

Once you start actually wrenching, you'll notice the next big advantage. Click-type torque wrenches get their name because of the distinctive click they make when they hit the desired torque. The thing is that some of them have a click that's easy to miss with a small amount of dead area that is easy to blow past. The Giustaforza 2-16 Pro has a loud click and a solid dead zone that feels very positive and rewarding to hit. You'd have to try really hard to overshoot this one.


There's no doubt you can get a cheaper, equally capable, torque wrench. Marketing hype aside, the number of clicks and accuracy aren't super unique. Even the high-quality hardened steel bits will either come with the competition or you can buy them. Put all this together and it shouldn't make sense to spend the money on a tool like this but it's worth it on so many levels, not to mention the fact that it will last you a lifetime.

The biggest reason you might decide to make a different choice is that the price puts it into the company of electronic torque wrenches. An electronic torque wrench allows for measurement of torque in either direction of rotation and in whatever torque scale your part uses. On the other hand, they don't click and there is no dead zone. They flash and/or beep and you need to stop when you reach the desired setting. It feels better to use a mechanical wrench of this level even if it does lack some of the features that a digital option brings.

The only bugbear in terms of this particular wrench is the lack of a quality hard case to store it.

Testing scorecard and notes

  • Build Quality Every piece is absolutely top of the line and well considered. 10/10
  • Accuracy We don’t have a laboratory but values aligned with other wrenches and there is a guarantee. 10/10
  • Included Accessories The bits use quality materials but aren’t colour coded and there’s no hard case included. 5/10
  • Hand Feel This is a tool that feels incredible to use and when you reach the torque value it’s obvious and satisfying. 10/10
  • Overall rating 88%

Tech Specs: Effetto Mariposa Giustaforza 2-16 Pro torque wrench

  • Price: $290.99 / €276.99
  • Included bits: 2/2.5/3/4/5/6mm hex, T10/T15/T20/T30 torx, slotted and phillips screwdriver, 100mm x 4mm hex/5mm hex/T25 torx extension, and 10mm extension with hex socket
  • Guaranteed Tolerance: +-4% tolerance for 5000 cycles with recertification available
  • Drive Size: 1/4-Inch Hex Shank with included adapter
  • Weight: 188g
  • Length: 150mm
  • Resolution: .5 Nm