Quarq riken/s975 drift - too much ?

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ajmit3
Posts: 205
Joined: Sun Mar 27, 2011 7:36 am

by ajmit3

Hi guys

I hope this is in the correct forum but I have been having issues with my 2nd hand riken which I got in about Dec 2014. Weight weenies is a great forum btw, lots of people with great technical knowledge about all things bike related....

1. Riken / s975
Its a bit of a funny unit in that it was apparently warranty replaced in June 2013 and it says 'riken' on it and the invoice says PM ASSY SPIDER R RIKEN SRAM 110' and the spider looks like a Riken and says Riken !. However, its got the old s975 style crankarms with SRAM on them. I'm 99% sure its a riken though.

2. The problem is this, apparently more than 50 units is a bad thing...

The figures are as follows
7 Feb 375
8 Feb (morning) 427
8 Feb (midday) 398
11 Feb 492
11 Feb (3 hours later) 443
12 Feb 396
18 Feb 437

Are these variances a problem ? :noidea:

TomHelly
Posts: 72
Joined: Sun Feb 22, 2009 12:31 pm
Location: UK

by TomHelly

From Quarq 'getting started' document:

TRACKING THE HEALTH OF YOUR POWER METER USING THE ZERO OFFSET
The zero offset should be between +1000 and -1000.
Ride to ride and day-to-day variation should be less than 50 points.
Values >1000 and <1500 are okay if the variation is <50
Values >1500 require examination

It seems borderline ok to me, ~50 points variance on consecutive days but <50 points change across several days.

On a positive note, your values fall in the 'healthy' range of +1000 to -1000.

Grab a torque wrench and check all your chainrings bolts are evenly tightened, might be as simple as that.

Tom

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AlphaDogCycling
Posts: 55
Joined: Fri Feb 15, 2013 6:57 pm

by AlphaDogCycling

I would also email Quarq and see if your Riken can be upgraded with the 10K temperature calibration.

I have a new Riken (November 2014) that has the temperature calibration and I only see +/- 5 over any length ride, and the calibration has been with 12 units day to day. I've been tracking this for every ride.


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davidalone
Posts: 622
Joined: Fri Feb 10, 2012 4:27 pm

by davidalone

What you most likely have, is an old S975 unit that was returned to quarq for a warranty replacement. Quarq then REPLACES the S975 spider unit ( which is where all the electronics are located - BUT not the crankarms because they are fine. ( FYI the spider and crankarms are detatchable, if you anted to replace those crankarms with say, the new S900 or Sram Force 22 crankarms you can actually do it, although quarq won't do it for you.) The same happened for me when I returned my S975 for warranty. They gave me back a new Riken spider with the old crankarms attached. you aren't missing anything because the S975 and riken crankarms are exactly the same, just different decals.

Depending on whether the previous owner used it after the warranty period, Quarqs need a small 'bedding in' period. check the torque on your chainring bolts is set to 10Nm, and that the attaching bolts between crank and spider are tight. if all is good, do some hard sprint efforts on them for 10 odd seconds.

Monitor the health of your riken calibration for a week after that, and if it persists contact quarq.

mentok
Posts: 577
Joined: Sun Jan 01, 2012 9:58 am

by mentok

As above, i'd make sure the chainring/spider interface is clean and clear then check the chainring bolt torque. those numbers seem acceptable but could possibly be better.

TomHelly
Posts: 72
Joined: Sun Feb 22, 2009 12:31 pm
Location: UK

by TomHelly

@davidalone nailed it :thumbup:

ajmit3
Posts: 205
Joined: Sun Mar 27, 2011 7:36 am

by ajmit3

Thanks guys for all your help ! :mrgreen: :thumbup:

goodboyr
Posts: 1483
Joined: Wed Jan 10, 2007 10:56 pm
Location: Canada

by goodboyr

Make sure you have latest firmware 23. Some earlier versions had bigger zero offset drift.

by Weenie


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tinozee
Posts: 764
Joined: Wed Jun 01, 2011 7:53 am

by tinozee

Yes Goodboyr is right, get a Ant+ dongle (Sunto mini movestick for PC) http://www.amazon.com/Suunto-Movestick- ... B004YJS3LG

Check firmware and all settings in Qalvin. Let it bed in for 2+ weeks. If it's still swaying I'd call Quarq. I wouldn't accept it swaying like that, at an increment of 50 it could mean a diff of 15 or so watts showing on your device.

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