Rotor’s Q Rings give the smoothest pedalling experience imaginable and with the ability to tailor the orientation to match your bike set-up, they offer a highly customisable performance upgrade.
While experimenting with different positions over time can help you hone your Optimum Chainring Position (OCP), INpower users can let Rotor’s User Software do the hard work for you by using advanced pedalling analysis to prescribe your ideal position.
A few months ago, riders from Team WNT joined us to find their OCPs – here’s the test protocol we used. All you need to do is to download the INpower User Software and perform the simple interval test outlined below. If you’ve not yet tried Q Rings, check out our reasons to love Q Rings article and Q Rings review.
Getting ready for the INpower test
You’ll need to get your bike on a turbo trainer or direct drive trainer for the test, making sure that the bike is level as it would be on the road. Once you’ve loaded-up the INpower Software and connected via ANT+, switch to the ‘Advanced Training’ tab. Here you’ll be able to keep an eye on the test duration, your power and your cadence; the three data points you’re interested in.
The test protocol
The INpower test is simple – three 90-second intervals at 80, 90 and 100rpm with one minute easy recovery between each. The tough bit is the interval intensity. Rotor’s protocol for pro teams is to work at 4.5 watts per kilogram of body weight. However, depending on the type of riding you’re doing, it may be better to have the wattage figure more accurately represent your chosen event. For example if you’re planning to hold 175 watts throughout an Ironman bike leg, it makes sense to use this intensity for your OCA test.
- 90 seconds at 80rpm (0:00-1:30)
- 60 seconds easy recovery (1:30-2:30)
- 90 seconds at 90rpm (2:30-4:00)
- 60 seconds easy recovery (4:00-5:00)
- 90 seconds at 100rpm (5:00-6:30)
Performing the test
Make sure you’re properly warmed up before beginning the intervals. You’ll need to remove the data for your warm up and recovery minutes following the test, so once you’ve pressed the ‘Begin Test’ button, be sure to note down exactly when your first interval begins. We’d recommend warming up first, then hitting ‘Begin Test’ and riding easy for the first 60 seconds leading into the interval.
Tips for test accuracy
- If you’re doing the test with Q Rings already installed on your cranks, start with them in position three.
- If you normally ride on the drops, ride on the drops. If your elbows are usually kinked, don’t let them straighten. Stay as close to your true position as possible, keeping your head facing forward, not craning at your laptop screen!
- Having a timekeeper with you, shouting interval start and stop periods, makes the test a whole lot easier and leaves you to just focus on power and cadence.
- It’s a good idea to find the gears you’ll need to hold your selected power and cadence in advance of the intervals so you know which ratios to change to at the start of the each 90-second effort.
Analysing test data
You’ll need to use Excel or a similar application to edit the resulting .CSV file created by the INpower Software.
Remove any data preceding the start of the first interval, then delete the two 60-second easy spins between the intervals. Finally, clear any data after the end of the final interval. You should be left with 4.5 minutes of data.
Use an average formula to calculate the average value of the final column – ‘OCA (deg)’ – to give you your overall chainring angle for the test.
Refer to the below OCP guidelines to see which OCP you should choose.
- OCP 1 = 73-81°
- OCP 2 = 79.5-87.5°
- OCP 3 = 86-94°
- OCP 4 = 92.5-100.5°
- OCP 5 = 99-107°
If you have a MAS crankset, you may be able to get an even closer position using the half-OCP increments below.
- OCP 1.5 = 76-78°
- OCP 2.5 = 82.5-84.5°
- OCP 3.5 = 89-91°
- OCP 4.5 = 95.5-97.5°
Extending the test
If you’ve got different bikes, such as road and time trial, you’ll need to perform separate tests for each.
INpower User Software – ANT+ troubleshooting.
If you receive an error message while trying to connect your power meter to the software via ANT+, it may be that Garmin Express is blocking use of the ANT+ signal while running in the background.
The error message: “ANTLibrary Exception: Failed to connect to any ANT devices” could indicate Garmin Express is conflicting with Rotor’s INpower User Software. Here’s how to remedy this:
- Open Garmin Express
- Go to Preferences
- Uncheck the box “Always keep Garmin Express running in the background”
- Close Garmin Express and try to reconnect in the INpower User Software