SRM vs. Quarq Cinco

jonmack

Hey all,

I'm wanting to buy a power meter, and it's between these two (as the pedal based systems have yet to materialise). It'll be on the SRAM S975 arms, GXP BB.

Looking through the 2011 team bikes seems like SRM is the pro choice, I've read that when CTT were testing the Quarq they had issues, but they've now been eradicated. I've also seen Alex's posts about calibration, and that's something that's on my mind, the fact that the Quarq has to go back to America to get re-calibrated currently, but then the SRM has to go back if the battery runs out, if i'm not mistaken?

I'm going to be using the power meter with a Garmin 705 if that makes any difference, can anyone give me any guidance?

The Swedish Chef

See today's cyclingtipsblog site for some good reading about this.

jibberjim

jonmack wrote:

Looking through the 2011 team bikes seems like SRM is the pro choice,

So SRM spend more money sponsoring teams? (Pros don't choose equipment!)

jonmack wrote:

the fact that the Quarq has to go back to America to get re-calibrated currently, but then the SRM has to go back if the battery runs out, if i'm not mistaken?

The SRM is correct, but the Quarq could be calibrated yourself, it depends how much effort you want to go into it, and going forward it's guaranteed to get easier to calibrate at home whereas the SRM will always have to go back for battery changes.

Alex_Simmons/RST

jibberjim wrote:

The SRM is correct, but the Quarq could be calibrated yourself, it depends how much effort you want to go into it, and going forward it's guaranteed to get easier to calibrate at home whereas the SRM will always have to go back for battery changes.

depends how much effort you want to go into it, you can change the SRM battery(ies) yourself.

jonmack

The Swedish Chef wrote:

See today's cyclingtipsblog site for some good reading about this.

I saw that article, Wade seems pretty happy with his Quarq.

So the calibration can be done at home on the Quarq, and the battery change can be done at home on the SRM if worse comes to worse...

I recall reading something about SRM taking recordings at 200hz, and the Quarq at 60? Is that difference noticeable, and does it effect accuracy that much?

jibberjim

jonmack wrote:

I recall reading something about SRM taking recordings at 200hz, and the Quarq at 60? Is that difference noticeable, and does it effect accuracy that much?

No, there is no practical difference in accuracy. Particularly as they actually integrate over 1 pedal revolution anyway so the 200 and 60 are irrelevant.

Petromyzon

I would be worried that SRM wouldn't honour the warranty if I re-soldered a battery. It's a little bit ridiculous that the market leader has to be sent back to base to change the battery, first step in any troubleshooting is usually to check relevant circuitry has power.

Ultimately I don't think you'll go far wrong with either device.

EDIT: Although I suppose battery life is longer than the 1 year warranty anyway.....ignore me.

Alex_Simmons/RST

jibberjim wrote:

jonmack wrote:

I recall reading something about SRM taking recordings at 200hz, and the Quarq at 60? Is that difference noticeable, and does it effect accuracy that much?

No, there is no practical difference in accuracy. Particularly as they actually integrate over 1 pedal revolution anyway so the 200 and 60 are irrelevant.

There are some analysis applications where there is a difference - maximal force-velocity testing for instance, where the temporal resolution is inadequate on a Quarq to perform such analysis. This would be of particular interest to sprint / track TT and BMX riders.

I forget what the torque sampling rate on a Quarq is. Powertaps are 61Hz IIRC.

sungod

quarq's faq says...

The CinQo samples at 60 Hz and averages the measurements over each crank revolution.

The CinQo will complete a power reading every crank rotation. So, if you are pedalling at 90rpm, power data will be received by the computer every two-thirds of a second.

The hardware is capable of higher sampling rates and we plan to implement this in later firmware versions. We know that track cyclists in particular are seeking higher sampling rates to analyse standing starts.

Firmware upgrades must be performed at the factory. This will be a free service, plus freight.

Team Banana Spokesman

seems pointless to me as we only record at 1hz? :? if everythings averaged it shouldnt really matter much.

if only we could record the data at 60hz and above......

jibberjim

Team Banana Spokesman wrote:

seems pointless to me as we only record at 1hz? :? if everythings averaged it shouldnt really matter much.

if only we could record the data at 60hz and above......

The SRM powercontrol can record at 0.5 seconds (standard ANT+ power can't go more than 4 times a 2nd) And sampling still matters even if you're averaging to to 1 second, since you don't push down evenly. However I don't believe the difference between 60 and 200 is relevant given the stated accuracy of the devices.

liversedge

Alex_Simmons/RST wrote:

jibberjim wrote:

The SRM is correct, but the Quarq could be calibrated yourself, it depends how much effort you want to go into it, and going forward it's guaranteed to get easier to calibrate at home whereas the SRM will always have to go back for battery changes.

depends how much effort you want to go into it, you can change the SRM battery(ies) yourself.

I thought that invalidated the warranty ? Also, you need to use a soldering iron?

Alex_Simmons/RST

liversedge wrote:

Alex_Simmons/RST wrote:

jibberjim wrote:

The SRM is correct, but the Quarq could be calibrated yourself, it depends how much effort you want to go into it, and going forward it's guaranteed to get easier to calibrate at home whereas the SRM will always have to go back for battery changes.

depends how much effort you want to go into it, you can change the SRM battery(ies) yourself.

I thought that invalidated the warranty ? Also, you need to use a soldering iron?

By the time your battery goes dead, it would be out of warranty.

I'm not advocating it, just saying it's possible.

Keep in mind that some people are far handier with a soldering iron than they are with programming computer equipment/devices.

Some threads:
http://groups.google.com/group/wattage/ ... ef0a9ea2a#
http://groups.google.com/group/wattage/ ... 88d5b8d48#
http://weightweenies.starbike.com/forum ... =3&t=24359

jibberjim

Alex_Simmons/RST wrote:

I thought that invalidated the warranty ? Also, you need to use a soldering iron?

By the time your battery goes dead, it would be out of warranty.[/quote]

Indeed another deficiency of the more expensive SRM - they only give it 1 years warranty against Quarq's 2. Of course in the EU SRM will actually have to provide a 2 year warranty in reality although it may take more effort to enforce it.

Alex_Simmons/RST

jibberjim wrote:

Indeed another deficiency of the more expensive SRM - they only give it 1 years warranty against Quarq's 2. Of course in the EU SRM will actually have to provide a 2 year warranty in reality although it may take more effort to enforce it.

?
All SRMs I sell come with a 2 year warranty.

And I sell 2 models of SRM for less $ than you can buy a Quarq.

jibberjim

Alex_Simmons/RST wrote:

All SRMs I sell come with a 2 year warranty.

Yes, but that's in Aus, in other countries the warranty rules are different.

Alex_Simmons/RST

jibberjim wrote:

Alex_Simmons/RST wrote:

All SRMs I sell come with a 2 year warranty.

Yes, but that's in Aus, in other countries the warranty rules are different.

Sure, but don't make out that Quarq is always cheaper or has a better warranty. 2 year warranty when purchased from SRM Germany and Oceania. I'm not sure about UK.

Not only is Quarq more expensive here, any issues and you have to send it to the US. Which is a PITA and expensive. SRM has local service here. And in NZ.

jonmack

I'm prepared to drop the coin this week, who want's to decide for me?

richa

SRAM SRM = £1,840
SRAM Quarq = £1,440

I think they are pretty comparable, price difference is £400...

jonmack

Are Winstanleys reliable yet? Everything I've heard about them in the past hasn't been very positive.

hopper1

jonmack wrote:

Are Winstanleys reliable yet? Everything I've heard about them in the past hasn't been very positive.

Bought my Quarq from Fudge Cycles, not sure what their current price is, but you wont beat Fudges for service...

TarmacExpert

jonmack wrote:

Are Winstanleys reliable yet? Everything I've heard about them in the past hasn't been very positive.

I got my Wingspan helmet from them. It was out of stock when I ordered, and they were quite good at emailing me regular updates on when it was expected to arrive in stock.

I would also seriously consider Power2max, personally, and also Rotor rather than SRAM, as I'm not a huge fan of the GXP BB system. I use Hope BBs with the GXP adapter and I've found that over time, the two halves of the adapter can become compressed together, applying excessive force on the bearing and making it rather stiff. I'd say the Hollowtech system, which is basically what the Rotor uses, is probably better, though a little more time consuming to swap between bikes than GXP. GXP becomes particularly problematic when used with pressfit bearings such as Trek, I'm really not keen on how it works on my Speed Concept, and am seriously considering a Rotor Power2max to put on it instead of my SRAM Quarq.

jonmack

Thanks for that, I bought mine from Cycle Power Meters, they were out of stock of 172.5 unfortunately but should be getting them in tomorrow and said it will be with me for early next week.

EDIT: I did consider the Rotor, but ended up going with the S975 instead as it matches the rest of my groupset, sad I know! If you do end up selling your SRAM Quarq, give me a shout, depending on finances I could take it off you for my winter bike, save switching cranks out.