GPS cycle computers are not cheap, the ‘usual suspects’ such as the Garmin Edge 130 or the Wahoo Bolt are usually priced north of AUD 250. Miles is a new GPS cycle computer from Shanren, a Chinese brand who have released a few bike tech products including lights, a bike camera, heart rate monitor and the existing Discovery Pro GPS Cycle Computer. Breaking away from clunky designs, the Miles cycle computer could be the cheapest way to get a GPS cycle computer onto your bike.
The Hammerhead Karoo, Trimm.bike computer and the XOSS Sprint all ran successful kickstarter campaigns and crowdfunded projects to finance the tech before committing to production. The new Miles follows suit has just launched on Kickstarter and with the ca. AUD 6,500 funding goal has only taken a few days to quadruple their target. However, for the last few years, the Kickstarter crowdfunding platform is more of a marketing platform and Shanren previously used it to fund and promote heart rate monitor and Raz-pro bike light.
The early bird price is approximately AUD 85 and the eventual retail price will be about AUD 115 which makes it a very cheap GPS cycle computer that has a few interesting features… most notably, “World’s First Power Estimation”. You don’t need to get a power meter any more as the Miles cycle computer. Let’s come back to Power Estimation later and look at some of the other details. The Shanren Miles is the latest evolution of 8 years of Bike Computer with Integrated bike lights.
The Miles is the first model without the integrated bike-light so sports a more modern and compact design weighing 65 grams. It follows the Discovery Pro and is the second product to include GPS functionality. In this day and age where bike riders rely more on navigation and recording and tracking their tours, GPS capability is a must-have for many bike riders.
The Miles uses the familiar Garmin style mount and there are speed and cadence sensors along with a heart rate monitor and an optional ‘out-front’ mount accessories. The unit is fairly compact measuring 73 x 52 x 20 mm and the LCD screen (2.1″) is set in the unit with a generous black border which eats into some of the ‘visual real-estate’. The product photography shows fairly unusual curved digits… whether this impacts legibility is unknown. There is a backlight and suggested total run-time of 20+ hours (following 2.5 hours charging) which would suit the needs of most riders.
The Miles unit appears to have only three buttons (on the bottom) to interact. While there is an app, it remains to be seen whether interaction can be as fluid and intuitive as riders need considering that most other GPS cycle computers have more buttons or a touchscreen.
The GPS is pitched to be ‘highly accurate’ and there is cross-over with the GPS satellites used by other brands. The Miles computer uses GPS (US), GPS BDS (Chinese), GPS+GLONASS (Russian) which they suggest it provides the following accuracy:
Speed accuracy: 0.05m/s
Heading accuracy: 0.3°
Horizontal accuracy: 2.5m
Noted, the positional accuracy is not documented however as a guide, US GPS satellites typically provide accuracy of 7.8 meters (95%) and for bike riders this is usually more than sufficient for route planning and recording trips. Without going into more depth on GPS, I don’t feel that the GPS accuracy of the Miles needs to be questioned.
However, the scope of the GPS functionality supported by the Miles computer is unknown. Recording a ride is usually fairly straight forward but the real magic is route-planning and turn-by-turn navigation which is where there are significant differences between brands. Currently Shanren have a 4-year old Sports app (Apple iOS) though this doesn’t yet appear to cover the new navigation functionality so perhaps the app will get an upgrade and more details will follow.
There is an optional taillight (Raz-Pro) which can sync with the cycle computer and can be set to control the light-mode and for example, trigger brake warning lights. As expected from modern cycle computers, the BLE and ANT+ capabilities allow connections with other sensors and devices.
Power Estimation without a Power meter. Can it be done?
The serious cyclists and data nerds will not be satisfied at all with the estimate as it won’t provide data that can be used for live training, racing or analysis. These metrics will remain more of a curiosity for the rest of the riders who don’t see the value of investing in a power meter… but will be happy with a rough idea of their average power output.
The graphed ‘estimated power’ hardly shows any peaks in power output and appears to show an average. I enquired about the maths and received the following overview to describe how the Estimated Power is calculated.
(1) Friction
(2) Acceleration
(3) Climbing power
Here are some of the factors:
• speed
• the coefficient of friction
• The total mass of the bicycle and the human body
• acceleration of gravity
• horizontal acceleration
• horizontal speed
The first variable “Friction” could mean deceleration and “Climbing Power” would not be actual power, more likely a calculation of time, speed and accounting for the gradient. Perhaps they meant to say ‘vertical acceleration and speed’ but generally, all of these metrics can be captured from GPS data except for coefficient of friction. So that is probably another calculation from the rider movement against a static environment.
I would compare the calculation of Power Estimation with the Strava calculation of calories. It is an estimate that loosely correlates to the rider effort. Dr Howard Hurst, a senior lecturer in sport, exercise and nutrition sciences at the University of Central Lancashire suggests, “Strava has a margin of error somewhere between 25 and 50%”. (source: YellowJersey UK). Serious athletes will take the data with a grain of salt but even the Power Estimation averages will give a rider a rough idea whether they are a world-class climber… or just out on the bike for the joy of riding.
Just the facts please
If you already own a GPS Cycle Computer, the Miles is not an upgrade, even with the novel Power Estimation feature. However, if you don’t have a cycle computer, this is a fairly cheap way of getting started. The Chinese brand Shanren now have a few years market experience and it appears that the Miles cycle computer can start to mingle with the other brands.
Other newer entries such as the Hammerhead Karoo and Trimm.bike prove it takes time and experience to deliver more well-round products of the likes of Wahoo and Garmin. In this respect, the Shanren Miles will probably come with a collection teething troubles.
If you are interested in getting started, consider opting for the second package (USD79 / AUD 102) which includes an ‘out-front’ mount. The cheapest option comes with a basic O-ring mount which are fine, but an out-front mount puts the computer in a better viewing position and clears the space around the handlebars. The size of the out-front mount is not specified (bike handlebars tend to come in two diameters, so this is a detail to check), but you could probably use any Garmin compatible mount.
It is no secret that the Kickstarter Crowdfunding Campaign for the Shanren Miles GPS Cycle Computer is primarily a marketing tool, mass production is already earmarked for March 2021 and delivery set for April 2021. For ‘backers’ the chances are good that this product will indeed be shipped-out but also consider any extra shipping costs and taxes. A risk for new products remains the reliability and customer support so also weigh this up if you are considering that this can match.
In summary, this is a low priced GPS cycle computer that should deliver all of the basics although may not have the finesse or functionality available in more expensive computers.
More details: Shanren Miles GPS Cycle Computer
Photos © Sharen and sed with Permission
