Sorry to bring the power topic up again

A light bike doesn't replace good fitness.

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fat tire
Posts: 354
Joined: Wed Mar 19, 2008 6:54 pm

by fat tire

I did a lot of research last night on the power meter topic last night.
I would like a final consensus. I have determined SRM is the best but I do not want to drop that much on a powermeter. I feel there are way cooler bike parts to spend money on than a powermeter.
So in my situation that leaves the Quarq vs Powertap. I live in an area where temps change a lot and the Quarq seems very tempermental to that. I do not feel like calibrating the thing every 1 hr on a ride, but I do like the fact that it is crank based. Another plus is that I do get a great deal on Quarqs. For $300 dollars less I can get a powertap slc+ with hed belgium rim with cx ray spokes for $300 less. I have been using a powertap for the last 5 years with no problems. I will not be racing this bike and if I do I do not care if I have power. So the rear wheel weight is really a non factor. Sorry Weight weenies. I worry about the weight of my other bikes.

Is the calibration a pain to worry about all the time? When I ride I just want to ride, and I do not want to worry has the temp changed too much. Is a crank based meter really worth $300 more especially with a new quarq coming out next year?

Like I said before sorry to bring this topic up again.

Privateer
Posts: 383
Joined: Thu Feb 03, 2011 2:28 pm

by Privateer

I've got both Quarq and Power2Max. I prefer the Power2Max because it re-zeros itself whenever you stop pedalling. The Quarq requires you to back pedal half a dozen times, which is fine when descending but is actually a bit of a pain when you're riding on the flat.

With re-zeroing feature temperature changes aren't a problem, even when going from 20 degrees in the house to sub-zero outside, or from low temperatures on the top of cols to moderately high ones in the valleys.

Frankly I can't see how the cost of an SRM can be justified. For the vast majority of us there's no functional difference between it and power2Max or Quarq.

by Weenie


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devinci
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Joined: Sat Jan 03, 2009 9:43 pm
Location: Canada

by devinci

well a used wired SRM is very affordable if you keep looking a bit.

IMO the cost of an SRM is easily justified, here's what mine has gone through:

-freezing temperture (below 0 deg C)
-rain, water, salt
-Race with soil road where it was raining, there was sand all over the place
-Crash

It is wtill working perfectly, every time I need it, it just works. It doesnt have any revolutionary feature, but it works flawlessly and gives you reliable and constant data.

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Rick
Posts: 2004
Joined: Sat Aug 29, 2009 4:30 pm

by Rick

Every time I calibrate my Powertap SL+ the number is within 2 of 515. So I assume that means it is always within 0.4% of nominal. that seems very accurate.

The calibration takes a few seconds. Just stop the bike; take feet off the pedals and hold everything still. Navigate to the computer's navigation page (I'm using a garmin 500) and hit "calibrate". The calibration number goes blank for a few seconds and then a new number appears.
I have deliberately pulled over an calibrated at the summit of cold climbs and then again at lower altitutudes in much warmer conditions just to convince myself that the numbers are pretty constant. Now, I only do it once a week or so just for peace of mind. It is ridiculously easy.

It also has an "Auto zero" option that I have selected, but I don't really know how it works. I presume it resets "zero" when it detects that I am not pedaling.

phourgenres
Posts: 223
Joined: Wed Sep 21, 2011 7:19 pm

by phourgenres

Is the only advantage to the integrated crankset power meters a faster relay of power readings?

I was thinking if you have a wired unit (even though it is messy) you would have a faster readback time compared to a wireless. Anyone found this or the opposite to be true)?

chase196126
Posts: 219
Joined: Sun Oct 12, 2008 11:11 pm

by chase196126

phourgenres wrote:Is the only advantage to the integrated crankset power meters a faster relay of power readings?

I was thinking if you have a wired unit (even though it is messy) you would have a faster readback time compared to a wireless. Anyone found this or the opposite to be true)?


I have had both wired and wireless SRMs. Both report power at the same rate, no delay for either one (at least that I have noticed)

In all honesty you cant really go wrong with Powertap, SRM, or Quarq. I personally prefer the SRM because it is absolutely bomb proof, easy to check calibration with weights (no need for an Iphone app) and the zero offset system allows you to check after an interval and determine if your power was accurate (and adjust in the software or in your head if it is not).

You can find used wired SRMs for $1000 or less on ebay and not too much more for a wired system, especially if you already have a Garmin or some other ANT+ unit

me
Posts: 529
Joined: Mon Feb 18, 2008 7:44 am
Location: Australia

by me

To the OP, you say you have used a powertap for 5 years with no troubles, does that mean you still have your powertap?

If so and you're not racing why not stick with it?

fat tire
Posts: 354
Joined: Wed Mar 19, 2008 6:54 pm

by fat tire

The powertap I have been using is actually the 1st generation powertap. My buddy owned it before me. The wheel weights 4.5lbs with tire and cassette!!! The braking surface is buttery soft from using it so long. It has seen better days but it does still work.

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Spanielsson
Posts: 58
Joined: Mon Dec 15, 2008 7:30 pm

by Spanielsson

I switched to an SRM in June this year (Older wired Pro with PCV), I've found it to be fantastic with new batteries fitted. Zero the offset and away you go.... Change between training and race wheels without any problems and still have power measurement.

Powertap however is another story. If you are using a turbo trainer I would personally avoid a PT. I don't believe there are robust enough to withstand the extra loading through the axle. Between my good friend and I, we have had 4 PT repairs in a 12 month period. All under warranty luckily, but still unnecessary trouble we could have done without.

If I were buying again I'd go for a used SRM, there are super robust.

Geoff
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Location: Canada

by Geoff

davinci and Spanielsson have about covered it...

cookiemonster
Posts: 83
Joined: Thu Dec 25, 2008 9:00 pm

by cookiemonster

> I do not feel like calibrating the thing every 1 hr on a ride

Its no real effort with the Quarq; 4-5 back pedals every so often - a dip in the road, slowing down, whatever, it (for me at least) becomes almost unconscious. I (again personally) would discount it as a deciding factor between the units. I do a manual calibration before the ride, which takes about the same amount of time as it does to get the coffee covers off my pedals!

Its seems though when it comes to support that if you're US based then Quarq is the way to go as in the UK you're just a step away and can find yourself waiting on stock arriving from abroad. Whereas the reverse is true with the p2m - quicker support in Europe, and finding their way in the US.

jon

mattyb
Posts: 119
Joined: Tue Oct 07, 2008 9:21 am

by mattyb

You can replace the battery in the Quark in about 5 seconds
The SRM needs to be sent in.

How much downtime do you want for the sake of a battery?

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devinci
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Location: Canada

by devinci

mattyb wrote:You can replace the battery in the Quark in about 5 seconds
The SRM needs to be sent in.

How much downtime do you want for the sake of a battery?


sure but the SRM's battery lasts 3 times longer then the Quarq one. I sent mine not long ago and it took 2 weeks before I got it back. You get an accurate calibration along with the battery change too.

For me, the battery thing is worth it because the SRM is proven good, STRONG, and I know it wont let me down whenever I need it.

OJ
Posts: 860
Joined: Wed Aug 02, 2006 5:25 pm
Location: Winterpeg

by OJ

I switched to SRM as well. Just got it installed on my trainer bike this weekend so I don't have too much to say yet. I've been using PT for the past 4 years and while PT works really well too, crank based powermeter made more sense, as I was downsizing my cycling gear collection and got rid of my TT bike.

SRM is my #1 choice, PT #2 while P2M and Quark share the last podium spot. My PT's have been very reliable so that helps the hub system.
http://demarere.blogspot.com/" onclick="window.open(this.href);return false;

mattyb
Posts: 119
Joined: Tue Oct 07, 2008 9:21 am

by mattyb

devinci wrote:
mattyb wrote:You can replace the battery in the Quark in about 5 seconds
The SRM needs to be sent in.

How much downtime do you want for the sake of a battery?


sure but the SRM's battery lasts 3 times longer then the Quarq one. I sent mine not long ago and it took 2 weeks before I got it back. You get an accurate calibration along with the battery change too.

For me, the battery thing is worth it because the SRM is proven good, STRONG, and I know it wont let me down whenever I need it.


Sure but they are waaay more expensive and it's still two weeks to get it replaced.
My Quarq has never ever failed in ranges on 0 - 40 degrees C , indoors, outdoors, dirt raods blah blah blah. Same with my partners Quarq and others I know that have them.
Not saying you shouldn't be happy with SRM quality but there's nothing that convinces me that it's better than the Quarqs.

by Weenie


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