Forums » Quarq Discussion » S975 with 53/39 Force chainrings? (5 posts)

S975 with 53/39 Force chainrings?
lathamjohnp
6 months, 2 weeks ago

I see in your store that for the SRAM S975 you have 53/39 with the Red chainrings, and 50/34 with the Force chainrings.

The SRAM S900 crankset is available with SRAM Force chainrings in either 53/39 or 50/34.

Is it possible to order the S975 with 53/39 Force chainrings?

Alternatively, if I was to fit aftermarket Force chainrings would it affect the calibration?

John
Mieke@Quarq
6 months, 2 weeks ago

Yes, you can request to get the SRAM S975 with 53/39 Force rings if you prefer. Just put a request in the "notes" section when you place your deposit in our webstore.

The SRAM Red and Force rings are within 1% of each other in regards to calibration so it wouldn't matter too much if you swap the Red rings with Force rings after you received the CinQo either.
Izzy
6 months, 1 week ago

Didn't realize there was a calibration issue with switching rings...... I have ordered S975 with 53/39 Red rings as well. However, I have a set of Rotor rings (53/39) that I will most likely be using. Any issue with switching red with rotor rings back and forth?
lathamjohnp
6 months, 1 week ago

Izzy, see here:

http://www.quarq.com/forum/thread/38/

"Q-Rings have a very similar calibration to SRAM rings. You can swap them out and only change the calibration by about 1%. This includes both Road and Aero Q-Rings. SRAM and FSA solid TT rings do change the cal by about 5-6%. If you want us to recalibrate with the new rings you are welcome to send it in."

Personally speaking (as a customer) I don't see 1% as a big deal, since (a) the stated accuracy of the Quarq system is +/-2% (b) 2 or 3% is within the normal variation for power tests, in my experience.

Even if you were changing the rings every day it wouldn't matter much, What matters is that you're measuring output (power) not indirect effort (HR).
Izzy
6 months, 1 week ago

great. Thanks

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