Effetto Mariposa Giustaforza 2 Pro Review

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Effetto Mariposa Giustaforza II Pro Torque Wrench
Photo Credit : Effetto Mariposa

Effetto Mariposa was established by Alberto De Gioannini in Italy in 2007 when he couldn’t find a quality bicycle-specific torque wrench for his personal needs as a cyclist. In 2014, the brand moved to Switzerland where it is still today.

The company set out to solve the problem of the lack of high-end, precision, mechanical torque wrenches dedicated to working on today’s premium bicycles and components.

The Giustaforza 2- 16 Nm torque wrench exists in three versions. Because they are premium precision tools, they are on the swanky end of anyone’s budget.

Technical Specifications

  • Torque range : 2 to 16 Nm.
  • Tolerance : +/-4%
  • Age range : 5,000 clicks / calibration – a lifetime for most users

Who is it For?

Effetto Mariposa Giustaforza 2
Photo Credit : Effetto Mariposa

The Effetto Mariposa Giustaforza 2-16 Pro is for the discriminating cyclist or any home or professional shop mechanic who is an avid fan of bicycle tech and appreciates quality tools presented as a unique piece of art. 

This torque wrench is exceptional and built to last.

Our Opinion

The Giustaforza is the height of luxury for making torque adjustments. It’s simple, effective, and carries a ton of style points!


  • High-quality construction. It would be difficult to find anything superior in its class.
  • Accurate. Tolerant to +/- 4% and an audible click is heard when the set torque is achieved.
  • A piece of art. Who wouldn’t want to have a precision tool that doubles as a masterpiece in their workshop?


  • Spendy. Not everyone is willing to pay so much for an occasional tool.
  • Less clearance. Its ¼” ratchet head can make negotiating tighter spots more of a challenge.

Superior Construction Quality

Every Effetto Mariposa Giustaforza torque wrench is made in Italy from a hard-anodized aluminum body. And each one is treated as a collectible, identifiable by its own laser-etched number and Effetto Mariposa logo.

Because the wrench is all-metal, it’s extremely forgiving against brutal shocks or falls. To facilitate grip when adjusting the newton-meters (Nm), the lower body of the wrench and the adjustment dial for the calibrated spring is knurled.

The Giustaforza 2-16 Pro has the appropriate length for its range of torque. A wrench that is too long creates an excess of leverage which may lead to breaking or stripping your bicycle’s screws and bolts.

The simplicity of the 2-16 pro and its mechanical, click-type action means it works flawlessly without the need for any batteries. This tool is well balanced, and its construction just feels good in the hand.

Professional Grade Accuracy

Effetto Mariposa Giustaforza 2 Pro 6
Photo Credit : Effetto Mariposa

Guesstimating when adjusting a bolt or screw is out-of-date for today’s lighter, sensitive components. Using a proper tool is safer for your expensive equipment and more reliable than force alone.

An accurate torque wrench is vital to any home or professional bicycle workshop. The tolerance level of the Giustaforza 2-16 Pro is +/- 4% which classifies it as one of the most accurate.

The 2-16 Pro’s precision is guaranteed by Effetto Mariposa for 5,000 clicks (the audible noise heard when the set torque is achieved). This should be a lifetime of adjustments for most, but if you’re a heavy user, the brand can recalibrate it for a small fee. Recalibrated tools are returned with certification.

Using the Giustaforza 2-16 Pro will maintain your state-of-the-art bicycle’s nuts and bolts, increasing their lifetime. Adopting the practice of using one saves you money and is an insurance policy of sorts regarding your personal safety and those you ride with.

Amazing User Experience

Effetto Mariposa Giustaforza 2 Pro 9
Photo Credit : Effetto Mariposa

If you haven’t used a premium tool like the Giustaforza 2-16 Pro before, it’s hard to describe the user experience. Using the best makes any job easier, more enjoyable, and guarantees a positive outcome.

On the other hand, the 2-16 Pro is well-balanced and perfectly sized. Its textured surface tells me when I have the right grip and position. The Nm window is laser etched and its markings clearly legible.

The ¼ “ head of the 2-16 Pro is larger than the brand’s smaller model, so certain angles present more of a challenge. I resolved any issues I had with the included extender (Deluxe set). The ratcheting action speeds up any task and is reversible.

The 2-16 Pro is easy to use. A thick line clearly illustrates torque values on the scale. The whole Nm is on the left and .5 increments on the right. An audible click tells you when the job is done, even at the lowest torques. As with any precision tool, reset it to zero after use.

Ideal Accompanying Accessories

Effetto Mariposa Giustaforza 2 Pro 3
Photo Credit : Effetto Mariposa

While you can purchase the Giustaforza 2-16 Pro as a wrench alone, I recommend you get the Deluxe set. If you’re going for it, you might as well go big, right?

The Deluxe version includes bicycle-specific bits that come in a convenient roll-up, the wrap-type soft case held closed by a velcro strap. The case fabric is agreeable to the touch and has defined pockets to hold each component.

The 2-16 Pro includes the following made from S2 shock-resistant steel for maximum durability, a 100 mm-long extension, three 100 mm-long bits (Hex 4, Hex 5, T25), and 10x25mm bits (HEX2, HEX2.5, HEX3, HEX6, T10, T15, T20, T30, -3/16, +PH1).

The bits enclosed in the Deluxe set to cover all the needs of the latest high-end Shimano, Sram, and Campagnolo groupsets, and aftermarket flippable stems. A handy illustrated user’s guide with clear instructions is included.

Available in 3 Variants

Effetto Mariposa Giustaforza 2 Pro 10
Photo Credit : Effetto Mariposa

The Effetto Mariposa Giustaforza 2-16 Nm comes in the following three variants. Any of these models are destined for a tech-savvy and discerning home or professional mechanic.

  • 2 – 16. It has a small head to work in tight spaces, is black anodized, and available as a wrench alone or in a Deluxe set.
  • 2 – 16 Pro. Identical to the 2-16, but in red anodized with a reversible ratcheting head (¼”) targeted for professional users. Available as a wrench alone, or in a Deluxe set.
  • 2 – 16 Pro Anniversary. Created to mark the company’s 10th Anniversary. Identical to the Pro, but in gun-metal grey, hard anodized. Only available in the Anniversary Pack, which includes a set of cycling-specific bits in a hard case.
Effetto Mariposa Giustaforza 2 Pro
  • Construction Quality
  • Accuracy
  • Ease of Use

Buy This If...

You want the ultimate bicycle-specific ratchet torque wrench that doubles as a piece of art to work on your high-end bicycle and components. It’s ideal for tech-crazy home and professional mechanics, or anyone who can appreciate fine craftsmanship and wants the best of the best.

How Much Does it Cost?

The Giustaforza 2 Pro retails for (Deluxe version) :

Effetto Mariposa Giustaforza 2 Pro Alternatives

Park Tool TW - 5.2

Park Tool Ratcheting Torque Wrench
Photo Credit : Park Tool

When separating with so much money for a once-in-awhile tool makes you flinch, yet you want a high-quality precision instrument for your bike or workshop, then the Park Tool TW-5.2 Torque Wrench is a premium alternative.

It’s a solid, highly accurate, click-type 2 to 14 Nm torque wrench that handles most tolerance requirements on today’s lightweight bicycles and components. Watch for a head pivot on lower torques as the click may not be audible.

It comes with a ⅜” drive compatible with left and right-hand threading. The dial is precise and if needed, a clever Nms to In lb conversion table is supplied. The Park Tool TW-5.2 comes in its own protective case.

Birzman Torque Wrench 3-15 Nm

Birzman Torque Wrench
Photo Credit : Birzman

The Birzman Torque Wrench 3-15 Nm is an economical option when you’re learning to wrench on your own bicycle and or want to adjust its sensitive components properly. While it isn’t as responsive as a higher-priced model, it provides enough feedback to let you know.

It’s ¼ “ drive torque action handles tolerances between 3 to 15 Nm, sufficient for most mechanics’ needs. The dial values are laser etched in .1 Nm increments, and adjustments are easy to make thanks to the wrench’s knurled texture.

Constructed from Chrome Vanadium, the wrench is durable and gets the job done. The set includes seven-bit sockets 3/4/5/6/8 mm, a T25 (star-shaped), and a 90 mm extender in its own storage case.

Dan Matthews

Dan used to race competitively in the amateur ranks until his mid-30s. He's married with 3 kids aged 5, 7, and 10. When not riding or writing, you can find him obsessing himself in his latest hobby, scuba diving.