# Quarq power meter



## Eyorerox (Feb 19, 2008)

Thinking of a crank based power meter, the Quarq Elsa 10R, would this be compatible with Chorus 11, I have an English Bottom Bracket. would I need to change the front Derailleur. Does any one have any real life experience.
Thanks for any help


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## tom_h (May 6, 2008)

*Done that*

I just finished installing a Quarq Riken on my Chorus 11 bike (Specialized Sworks Tarmac SL2)

You don't have to change front derailler,but you will have to re-setup the FD from scratch.

Here are 2 threads I made on the subject, 
http://forums.roadbikereview.com/campagnolo/11sp-chainline-301935.html
and
http://forums.roadbikereview.com/components-wrenching/chainline-campy-11-speed-vs-sram-303151.html

I'm still recovering from a cracked rib, and haven't done any actual road testing yet, just some easy trainer cycling.

The front shifting speed & quality on the SRAM chainrings is not nearly as good as Campy, but I'll need to do road testing to verify. I am pretty demanding of front shifting, as I road race. 

If the SRAM chainrings don't meet my needs, I'll switch to Stronglight. My previous experience is Stronglight 11sp chainrings work as well as Campy.

The chain angle the Quarq creates, could be a little more severe in the big-big combination, depending on your frame. I'd strongly recommend a chain catcher, if you don't already have one.


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## Eyorerox (Feb 19, 2008)

Thanks
Is the Quarq Q factor bigger than the Chorus?
Can you use any chainrings with the Quarq, how easy is that?


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## tom_h (May 6, 2008)

Both cranks' Q-factor is spec'ed the same: 145mm, IIRC.

I measured Chorus at 145-146mm, and the Quarq/SRAM was maybe 0.5-1mm wider. Probably within manufacturing tolerance and surely Unnoticeable.

Chainrings have to be common standard 110mm or 130mm BCD. This rules out Campy 53/39 (135mm) or Campy compact, which has 1 bolt offset to a 112mm BCD position. 

Previous generation Quarqs were very sensitive to chainring flex, and Quarq maintained a list of "supported" rings at their website.

New generation Elsa & Riken are supposedly much more tolerant ("Omnical" feature) of chainrings. Officially Quarq supports only SRAM rings, but other sources indicate most other chainrings will work fine, although a recalibration is probably a good idea.

Additionally, an experienced usear at Wattage forum (Tom Anhalt, i think) states for best results after changing or replacing rings,

- apply friction paste to the interface between rings & spider.
- only use _steel _chainring bolts (came standard on my Quarq Riken).
- torque to 10-12 N-m in a criss-cross sequence.
- do several hard, all-out starts, in both small and big rings.
- re-torque, as above.


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