Racing Meter For Torque Pro 40
Tension in the fastener depends largely upon the amount of torque, the tightening, and the size of the thread. Generally, engineers will specify a thread size large enough to handle the anticipated stresses. For example, the M5 bolt of a water bottle cage bolt would not be a good choice for holding a crank. Even if the bolt were as tight as possible, it would not provide enough force to hold the arm secure to the spindle. The crank-to-spindle interface receives quite a lot of stress, making larger threads (M8, M12, M14) a better choice. The amount of pressure applied by a thread can be substantial in order to hold the joint secure. For example, a fully tightened crank bolt can provide over 14,000 Newton force (3,000 pounds force) as it holds the arm in place.
racing meter for torque pro 40
Torque is measured as a unit of force acting on a rotating lever of some set length. In the bike industry and elsewhere, the common unit used to measure torque is the Newton meter (abbreviated Nm). One Newton meter is a force of one Newton on a one meter long lever. Another unit sometimes seen is the Kilogram-centimeter (abbreviated kgf-cm), which is a kilogram of force acting on a lever one centimeter long. It is possible to convert between the various systems.
Also sometimes used in the United States is the inch-pound (abbreviated in-lb.).This is a force of one pound acting at the end of a lever (wrench) that is one inch long. Another torque unit used in the USA is the foot-pound (abbreviated ft-lb.), which is the force in pounds along a one-foot long lever. It is possible to convert between the two units by multiplying or dividing by twelve. Because it can become confusing, it is best to stick to one designation. The units given on the torque table here will be in inch-pounds.
Torque wrenches are simply tools for measuring resistance to rotation. There is a correlation between the tension in the bolt and the effort it takes to turn it. Any tool, even a torque wrench, should be used with common sense. A cross-threaded bolt will not properly tighten even with a torque wrench. The mechanic must be aware of the purpose of torque, and what torque and fastener preload are doing to the component joint. It is also important to consider thread preparation, which is discussed in detail in this article.
All figures in the table below are in Newton meters and inch-pounds. Note that some companies do not specify torque for certain components or parts. Contact the manufacturer for the most up to date specifications.
This past summer at Eurobike, Quarq announced their latest generation of power meters, the DZero lineup. The aim of this line was to refresh the existing offerings, while also somewhat simplifying things. Most visible to consumers though was the addition of Bluetooth Smart transmission, making for dual ANT+/Bluetooth Smart capabilities. Alongside that was an updated multi-color LED for status clarity. Behind the scenes, the company tweaked the strain gauge design to increase accuracy levels. Finally, the company also added support for Boost 148 and BB386 EVO bottom bracket compatibility. Phew.
Like any power meter, getting the Quarq installed will vary depending on what your current bottom bracket setup is relative to whatever you bought from Quarq. If you were smart, you bought the same bottom bracket setup, and thus your installation is pretty quick and easy. If instead you elected to introduce unnecessary pain and confusion, then you bought some other standard and now need to also convert your bottom bracket. That, in turn, may be easy, or you could spend all day waiting for glue to dry.
As always, I set out to find that out. In power meters today one of the biggest challenges is outdoor conditions. Generally speaking, indoor conditions are pretty easy to handle, but I still start there nonetheless. It allows me to dig into areas like low and high cadence, as well as just how clean numbers are at steady-state power outputs. Whereas outdoors allows me to look into water ingest concerns, temperature and humidity variations, and the all important road surface aspects (i.e. vibrations).
In my testing, I generally use between 2-4 other power meters on the bike at once. I find this is the best way to validate power meters in real-world conditions. In the case of most of these tests I was using the following other units concurrently:
(Note: All of the charts in these accuracy sections were created using the DCR Analyzer tool. It allows you to compare power meters/trainers, heart rate, cadence, speed/pace, GPS tracks and plenty more. You can use it as well, more details here.)
With DZero we received reports and saw ourselves that cadence would sometimes bounce up and down on head units around a steady/single value. Thanks to great input (and patience) from customers and sound work by our engineers we have removed the bouncing from the display but also improved the sampling rate and further refined accelerometer readings such that DZero now matches the accuracy of magnet-based cadence. This is something we are very proud of!
I have an odd question in comparing the Quarq Dzero and the Watteam Powerbeat. The Dzero is heavier, about 170g to 43g, and the Powerbeat has a lot of unaero edges and stuff on your crank arm. Assuming a normal course with moderate hills, which would be a bigger penalty for toting your power meter along in a race, the Quarg weight or the Powerbeat non-aeroness (to make up a word)?
We have tested the power outputs of Quarq DZero and previous generation power meters versus trainers. We have seen them match and seen discrepancies like you describe. In our testing, making outputs match was heavily dependent on the gear you used and in turn how fast the trainer was spinning. You could do a similar comparison test yourself using a fixed power output, moving from the top of the cassette to the bottom in uniform intervals, and comparing the intervals afterward.
I would recommend using one device indoors and one outdoors, and doing an FTP test on both, to ensure your training zones are correct and that overload and fatigue are properly managed. Quarq DZero has dual ANT+ and Bluetooth Low Energy, so it becomes an option for both environments when compared to our previous generation power meters.
TroyIs there an issue with the readings showing right/left leg balance? Mine seems to be getting worse. To test the accuracy, I uncliped my right leg and rode a mile with only my left leg. No change on results. Is there a way to know if the issue is with the power meter?Thanks
Thanks Troy, really appreciate that the guys at Quarq are answering at our questions. I will read the researches, but also encourage you to introduce some metrics as the ones mentioned above into your power meters.Thank you!
Hi iomk. The best Quarq power meter for your bike is Quarq DFour GXP, like you suggest. You must combine it with a PressFit GXP (BB86 Road) bottom bracket. Quarq power meters are built on SRAM crank arms, which use a tapered spindle. You must pair them with a SRAM bottom bracket. If you want more info on compatibility or help with selection, please email the Customer Service team on thinkfast@quarq.com.
Some bikes from Canyon, Cannondale, Cervelo, Felt, Focus, Fuji, Trek and others use SRAM RED and Quarq Prime Power Ready Cranksets that can be upgraded with a DZero power meter spider. Bikes with BBright or BB386EVO bottom brackets, such as those from Cervelo and Felt, have the Power Ready version of the RED crankset.
The 8-bolt interface ensures accuracy when power meter spiders are installed and uninstalled or swapped between crank arms in the field. The 8-bolt interface is designed to mimic car wheel nuts or lug nuts. The bolts secure and center the spider on the crank arms; they make for a rigid and reliable contact point.
Does anyone know whether this has an impact on the accuracy of the power data and where it comes from? The installation of the chainrings was done with a torque wrench, and I had enough rides to have it settled.
Hi Raúl. Your local Quarq distributor can recommend a shop in your region. link to quarq.com You could also order a set of colored battery covers from online retailers that stock Quarq products, such as Wiggle, Cyclepowermeters, Bike24, Bike-Components.de and, in the USA, Competitive Cyclist.
The small torque reading is torque inherent in the power meter from assembly and installation. Bluetooth low energy has no way to prevent this from showing. Qalvin Legacy, which uses ANT+, had a small buffer so the small values were not displayed.
Hi Mihai. Please contact Quarq customer service on thinkfast@quarq.com or speak to the dealer where you bought your power meter. The Quarq customer service team believe there is something wrong with your power meter. They said you could verify this using Qalvin BLE. The zero offset value will be significantly outside +/- 1000.
Totaly unusable unit, the power reading works only rondom. Calibration error 80. For the amount of money it cost i find this totally unnacceptable.Will send the unit back and buy a half of price, working, Stages power meter.
With regards to temperature compensation, German road bike mag TOUR has a powermeter test in its current issue. Lab and field tests which included temperature sensitivity tests (lab). They always take an engineering approach to testing.
Thanks for the answer, correct me if I say a wrong thing but by mounting the quar d four instead of the ultrat 6800 the total weight of the bike should remain unchanged right? What are the lowest light left power meters ever?
Hey Ray I am currently just window shopping on power meters a little bit. this new unit has my interest as the aluminum version can be had for 700$ after clever training discount. Just wondering how you think this stacks up vs say riken pm
I am considering putting this on a different bike but I am concerned that my current P2Max and Quark DZero will not report the same numbers and I want it to be consistent. Should I go with all the same powermeter on all bikes or will the P2Max and Quark D Zero parallel each other. I currently have that issue with my kickr and P2Max