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3T Eye Cycle Computer



Has some good points, but let down by some of the fundamentals

At every product is thoroughly tested for as long as it takes to get a proper insight into how well it works. Our reviewers are experienced cyclists that we trust to be objective. While we strive to ensure that opinions expressed are backed up by facts, reviews are by their nature an informed opinion, not a definitive verdict. We don't intentionally try to break anything (except locks) but we do try to look for weak points in any design. The overall score is not just an average of the other scores: it reflects both a product's function and value – with value determined by how a product compares with items of similar spec, quality, and price.

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Cycle computers can be an expensive element of cycling but they have become increasingly necessary for those looking to improve or even just upload their rides to Strava. 3T, better known for its pro-level stems and bars, has released the Eye to try to create an affordable option with much of the power of far more expensive units. It succeeds in some ways, but falls short on others.

It does this through connecting to your smartphone to use the powerful elements that it possesses. It's similar to the Wahoo Rflkt+ which we reviewed in 2014, now discontinued. 

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Installing the computer on the bike is relatively simple and there are a couple of options. Firstly it comes with a 3T stem mount, although this is only available for use with the 3T ARX II stem. It also connects to standard Garmin mounts, which is how I was using it. This is a little confusing as it doesn't come with a mount for this, so unless you have an ARX II, you will need to go out and buy a separate mount.

3T EYE Cycle Computer - from front

There are three ways the the computer can work. First it can operate as a basic computer by itself. It allows you to connect ANT+ devices to it, so you can see your speed, power, cadence and so on, if you have the necessary sensors. This mode does not record the data, though, instead just displaying it in real-time.

Secondly it can be connected to the phone and can work through a number of apps, according to 3T. However, I found it difficult to find how to use it without the official 3T app, although this can be set up to transfer the data directly to a number of third party apps including Strava, MapMyRide and Training peaks. Here it can use the phone's GPS to work out things like speed and courses and it also tracks your ride on maps.

Finally it can be used as a smart-bridge, allowing the data created through ANT+ devices to be transferred to your smartphone, making the data you can collect on the phone much more powerful. For instance, it allows you to track your power and cadence through apps, rather than predicting them or simply ignoring them altogether.

All three modes seem to work well, and despite the unit having a relatively small 25x33mm screen it is still big enough to see the necessary data clearly. It also comes in at 27g on the scales of truth, which is only slightly more than the 25g weight given by the company, but still very lightweight.

3T EYE Cycle Computer - underside

The 3T app works well and provides some very useful performance information. This includes power outputs, timings, training zones and a number of different elements. This data is clear to view and transfer to other apps, meaning you can see if you've got decent Strava segment times or track it against previous performances.

There are a few things that unfortunately let the computer down, though.

The device is used through three buttons on the front: left, right and centre. Left and right scroll through the regular stats, including time, heart rate, speed and so on. The centre button performs actions like turning it on and lap when connected to the smartphone. This is a very limited use, especially when you compare it to the Rflkt+, which allowed you to do almost anything with the four buttons on the unit. You can't change what does what on the computer, meaning that its use as anything except a display is limited.

In terms of using it, I like to acquaint myself with how computers work before I start any kind of testing. The documentation you receive with the computer is limited to discussing basic elements and there appear to be no clear instructions online or within the 3T app, which makes it difficult to use and would be very simple to remedy. Simple things like trying to work out how to get navigation on the device is almost impossible to find because the documentation either doesn't exist or is very difficult to find.

> Check out our guide to the best cheap GPS cycling computers here

It would also not work as a substitute for a regular computer for long rides simply because it drains the battery significantly when using GPS on the phone – one of the most important elements. It meant that my phone ran out of power after three hours of use, so I had no data saved for the last 20km and no way of contacting somebody if I got into trouble.

The RRP of the device is £94.99, cheaper than the Wahoo Rflkt+ but lacking many of the Wahoo's capabilities. Basic elements like the backlit display, mappable keys and displays and providing mounts with the computer are missing. 

Overall, the computer has some good elements, especially the app, but is let down by some elements, the most pressing being the lack of documentation, which makes using it a struggle even for somebody who has reviewed bike computers for years. It is small and easy to pair with the 3T app and the ability to use it as a basic data display is a nice touch, but bearing in mind it came out over a year after the Rflkt+ it has significantly fewer features.


Has some good points, but let down by some of the fundamentals

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Make and model: 3T Eye Cycle Computer

Size tested: N/A

Tell us what the product is for, and who it's aimed at. What do the manufacturers say about it? How does that compare to your own feelings about it?

3T says: "3T Eye is a robust, handlebar-mounted digital display that supports navigation and training."

It may have navigation, but given that the instructions give no mention of how to do get it and the app doesn't either, I can't claim it definitely does. It displays training numbers well though and through connection to the app records everything accurately.

Tell us some more about the technical aspects of the product?

It monitors the outputs both of training aids communicating via ANT+, and smartphones communicating via Bluetooth.

Paired with a suitable input device, it's capable of displaying key data such as speed, cadence, heart-rate, altitude, and power, in real time.

In Bike Mode, 3T Eye automatically pairs with any ANT+ sensor, such as a heart-rate monitor or power meter, and displays the data on its screen.

In Smart Bridge Mode, it captures data from an ANT+ sensor and transmits it via Bluetooth 4.0 to a compatible sports app running on a smartphone, as well as displaying the data.

Rate the product for quality of construction:

The construction of the hardware itself seems fine, but it lacks the intuitiveness needed in the software. With the buttons available and the Bluetooth connection, it has so much more potential.

Rate the product for performance:

Training numbers, display and ease of use are good, uploading to the app and sharing to others is also good. However, don't expect to be able to effectively use it on long rides without being able to charge your phone midway through.

Rate the product for durability:

Seems well made and waterproof, used it in some torrential downpours without anything bad happening.

Rate the product for weight (if applicable)

Tiny and light, one of the lightest computers I have used.

Rate the product for value:

Tell us how the product performed overall when used for its designed purpose

From the basic numbers perspective it worked fine, but the lack of documentation made it frustrating to use and battery life drain on the phone made it impossible for long rides. Aside from these it worked fine for what I used it for.

Tell us what you particularly liked about the product

The 3T app is really simple to use and connect the computer to, data shown is impressive and ability to simply upload to other apps is a strong feature.

Tell us what you particularly disliked about the product

The lack of documentation was by far the most frustrating element.

Did you enjoy using the product? No

Would you consider buying the product? No

Would you recommend the product to a friend? No

Use this box to explain your score

What could be a great computer is let down by a lack of instructions and poor UX design. When it has another very similar competitor product released before this, it is a real shame that 3T didn't try to include the same kind of intuitive elements.

Overall rating: 4/10

About the tester

Age: 27  Height: 6 ft  Weight:

I usually ride: Cannondale Supersix Evo 6  My best bike is:

I've been riding for: 5-10 years  I ride: Every day  I would class myself as: Experienced

I regularly do the following types of riding: commuting, club rides, sportives, general fitness riding, fixed/singlespeed, mountain biking

George is the host of the podcast and has been writing for since 2014. He has reviewed everything from a saddle with a shark fin through to a set of glasses with a HUD and everything in between. 

Although, ironically, spending more time writing and talking about cycling than on the bike nowadays, he still manages to do a couple of decent rides every week on his ever changing number of bikes.

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