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124Spider 04-27-18 05:46 PM

Power meters for a tandem
 
Hi,

My wife and I just got a very nice tandem bike, feeling that two people with vastly differing strengths can more comfortably ride together this way than on two bikes.

We're interested in getting power meters, for a variety of reasons. i have a power meter on my bike, so I understand the benefits and shortcomings.

So I'm wondering what the best value in two power meters for a tandem is; we want reasonably accurate readings, and reasonably consistent readings, but we'd rather not spend a fortune. And pedal-based probably makes sense.

Thanks!

Mark

Mark W 04-28-18 07:07 AM

I have used Garmin vector pedals for several years on our tandem and was happy with them. I just replaced them (after the electronics stopped working) with power tap P1 pedals. I don’t have a lot of results from them yet, but they generally get good reviews. I’d look at dcrainmaker’s website for an in-depth review of them, as well as others. I looked at getting the new Garmin vector 3 but they appear to be off the market for now.

The P1s were easy to install and pair with my wahoo element, without dealing with a torque wrench for installation like my Garmin pedals. Since we travel with our bike that’s one less issue to deal with, too. They have some minor issues with using look cleats, but their cleats are similarly priced. FWIW my look cleats seem to work just fine for now.

if I were looking to save money I’d get the single side pedals, the power tap P1S. There don’t seem to be a lot of drawbacks, but YMMV. Good accuracy and they give you the metrics to train or ride at—I haven’t seen much in the way of training guidance based on power balance between legs.

mark W

124Spider 04-28-18 01:23 PM

Thanks! The Garmin still is many weeks away from being available. The P1S looks good, except that it seems the clips are different from other clips, which would mean I'd have to change cleats between my road bike and our tandem bike. Is that correct?

Alcanbrad 04-28-18 07:20 PM

I too have been looking for a power meter set up for the tandem and nothing seems to fit the bill. I just saw this solution this week and am seriously considering it. IQ Square

I have a Watteam Powerbeat on my single and what I like about the IQ Square solution is it can go anywhere. I am thinking of getting a L/R and placing one sensor on the captains crank and the other on the stoker.

As for ride data with the unit set up this way: Average team power would be double average power. Average power Split between captain and stoker would be based on L/R pedal balance. Copying left to right and right to left in the dataset would allow analysis of each team member (I.e. create 2 data sets of ride, one with the left power meter data copied to right side and the other with the right data copied to the left). This might require a little spreadsheet massaging, but simple macros can be created to process the data. It isn't a perfect data set, but it is pretty close and should yield consistent results and I can move the units to front or stoker only, or to another bike.

Has anyone tried this with existing power meters?

I know the IQ Square is just announced and there isn't any user reviews, but what are folks impressions so far?

Mark W 04-29-18 08:05 AM

I’m using my standard look cleats without issue, but there might be small differences as the cleats wear per dcrainmaker.

Mark W 04-29-18 08:10 AM

Haven’t seen anything on a setup like this. I’ve used power pedals on the front and our son used his pedals on the back for a separate measurement that went to his head unit. I’m not sure what use you’d get for training or in an event by combining the two outputs—what would you do with it? Could be fun I guess but beyond that I can’t think of a reason. Too much engineer in me, I guess.

Mark W 04-29-18 08:13 AM

Sorry, I posted too quick—you’re trying to save money by buying only one 2 side unit and getting two datasets by doing some post processing. I think it’d be better to use two single pedal systems to save data manipulation after each ride but possibly your way could work.

mark W

Alcanbrad 04-29-18 01:01 PM

My thinking on the L+R is that I can use it anywhere: captain, stoker, captain+stoker, single bike. The savings of the lower cost is just a happy benefit of the flexibility.

Alcanbrad 05-01-18 04:13 AM

124Spider, it appears you haven’t gotten a strong endorsement for any solution. If you haven’t already, google DC Raimaker and read his comparison and deep dive reviews on power meters. No mention of tandems but good coverage of what is on the market

zecamara 05-01-18 06:21 AM

I am happy with several Stages meters, left side only crank arm type. Very repeatable, consistent readings.

You can find old models on clearance at their site, or ebay.

Great application is to have cross readings for power, detect when your partner isn't putting their share uphill. :-)

I see a left-side system, installed left in front, right in back, giving power of both to two separate headsets. Evil...

124Spider 05-01-18 11:13 AM

Thanks so much for the replies!

I was intrigued by the IQ Square idea, but I'm not willing to wait an indeterminate amount of time for the meters, and I doubt those will be ready before next year.

Because my wife's bike doesn't have a power meter (I have a Power2max on mine), a "solution" that transfers easily from the tandem to the road bike was attractive, which pretty much leaves pedals (or IQ Square) as the solution.

I did read the DCRainmaker 2017 rundown on power meters. My take was that the Garmin Vector 3/3S was the best of the lot. But Garmin was out, and won't have more for six weeks, at least. And our local bike shop only had the Vector 2, which isn't attractive. So I was thinking about the Powertap P1S, when I decided to see any online site had the Vector 3S. And they did. So I've ordered them, supposed to arrive tomorrow.

After we've had a good chance to use them, I'll report back.

Mayonnaise 05-09-18 10:39 AM

Send 'em back

I've been a bike rider/racer since the early days of Greg Lemond. I've been through all kinds of systems, components, books....on and on. Many of them turned out not nearly as important as I thought they would be.

Hitting middle age my wife and I decided to get a tandem. It was a decision that took 3 years to fully answer.

It was one of the best decisions we ever made. We love it.

It took some growth on my part to be able to enjoy the actual ride. All that male centric Agenda, Dissection, Analysis, Expectation had to be tossed out. Had to be let go. Oh, I could've kept it, but that leads to Argument and I didn't want any of that, not on the bike.

The best rule for happy tandeming is KISS. Keep it simple. A decent GPS is all you need. Start focusing on mutual perceived effort. Get a feel for how the two of you are riding the bike together. Don't bury your face in a screen after a ride to see your watts versus her watts on the climb up Mt Burlap. It can only lead to a fight.

Instead say, "we rode good today, honey, now lets go get that sandwich"

124Spider 05-09-18 12:42 PM

I'll pass, but I appreciate your input. For us, it's providing objective guidance for how we can better work together.

stewclark 05-14-18 04:35 AM

Good comment....after 30 to 40 thousand miles...you can Feel the power for each rider on the team....

OneIsAllYouNeed 05-14-18 12:13 PM

I'm curious if you can split a pair of Vector 3 pedals (and a regular set of Keo pedals) such that the stoker has one and the captain has the other. I think it would allow you to display both riders' power on the same screen (as right and left). It might make it more difficult to do rider-based analytics, however.

Our team appreciates having power and/or heart rate data on the tandem. When we're on spirited group rides, I'll often tell my current training zone to my stoker such that she can match it. For those sort of rides, it would be even easier if she could see my power data on her screen, as well as her data. There have been times when I'm soft-pedaling to not hit the brakes, while she's motoring along; similarly, there are times that I'll be surging well above threshold to hang with the group while she's blissfully unaware of the effort.

Another good excuse for independent power meters on the tandem: we'll go for rides during which one person needs to do intervals, but the other is on a rest day. Having independent feedback is critical for those sort of rides.

124Spider 05-14-18 02:10 PM

No, you cannot split a set of Vector 3 pedals. Garmin has them set up so that the left pedal looks for a right pedal; if it finds one, they'll talk. But the right pedal is always the slave, the left pedal is always the master.

We bought two sets of Garmin Vector 3S, both of which are left only.

And we are enjoying having them.

Mark

124Spider 09-06-18 11:48 AM

OP here with an update.

The Garmin Vector 3S pedals are working great, and we love them. My wife uses hers on her single bike, and likes having the data. And it really helps her figure out how much she needs to work on the hills.

All in all, a very fine addition to our tandem.

Mark

Mr IGH 09-07-18 03:28 PM


Originally Posted by Mayonnaise (Post 20330900)
Send 'em back...It took some growth on my part to be able to enjoy the actual ride. All that male centric Agenda, Dissection, Analysis, Expectation had to be tossed out. Had to be let go. Oh, I could've kept it, but that leads to Argument and I didn't want any of that, not on the bike...Instead say, "we rode good today, honey, now lets go get that sandwich"

LOL, WTF is your problem? If the stroker isn't pulling her fair share it's time to find another stroker!

At the last tandem club after-ride-meal I was listening to some wives discussing their husbands' Strava/PM/HR obsession. It seems the wives don't like all that crap. Nope, what they really want is a nice, challenging ride without the expectation that they have to put out a certain level of power or face the wrath of the hubby....

Carbonfiberboy 09-09-18 11:26 AM


Originally Posted by Mr IGH (Post 20553110)
LOL, WTF is your problem? If the stroker isn't pulling her fair share it's time to find another stroker!

At the last tandem club after-ride-meal I was listening to some wives discussing their husbands' Strava/PM/HR obsession. It seems the wives don't like all that crap. Nope, what they really want is a nice, challenging ride without the expectation that they have to put out a certain level of power or face the wrath of the hubby....

My wife and I have run a small business together for 45 years. We're used to working together. My wife loves that we both have HR monitors and that she can see my HR, so she knows she's doing her fair share. That's what we both want. We've been together a long time and that works for us. We both like knowing we're carrying our share of the load. She loves the tandem.

But you're also right. That's why tandems are known as relationship accelerators. Whatever problems you might have, the tandem will find them. Your relationship will get where it's going much faster, which is a good thing, sometimes to the peaks of satisfaction, sometimes the other way. Who needs to spend their life in an unsatisfactory relationship? Life is short. Find your soul mate. Who knows, maybe it's your current partner?

Interestingly, the tandem teams in our group are all deeply in love and had that worked out long ago. Most of them both post to Strava, which is a bit funny but the QOMs do accrue. Can't get Strava to add a tandem category to stop that. Also the whole world can see how they're doing together. Mostly they're right together on the suffer score.

Dean V 09-09-18 01:44 PM


Originally Posted by Carbonfiberboy (Post 20555744)
Most of them both post to Strava, which is a bit funny but the QOMs do accrue. Can't get Strava to add a tandem category to stop that. Also the whole world can see how they're doing together. Mostly they're right together on the suffer score.

I think it is a bit low to post results on Strava from a mixed team in the female category and get QOM's.
We have a seperate account for our tandem rides, have "tandem" in our name and post in the male category. To me that seems to be the fairest way to do it.

Carbonfiberboy 09-09-18 05:46 PM


Originally Posted by Dean V (Post 20555933)
I think it is a bit low to post results on Strava from a mixed team in the female category and get QOM's.
We have a seperate account for our tandem rides, have "tandem" in our name and post in the male category. To me that seems to be the fairest way to do it.

I totally agree. That practice should be discouraged.. We do the same as you. I have a premium Strava for my single and a freebie for the tandem. Can't see paying twice, but that's probably why couples do that. Don't want to pay for more than one. Nonetheless, I'm not going to call out my close friends over it . . .

danspano 11-11-18 08:22 AM

double trouble
 

Originally Posted by OneIsAllYouNeed (Post 20339648)
I'm curious if you can split a pair of Vector 3 pedals (and a regular set of Keo pedals) such that the stoker has one and the captain has the other. I think it would allow you to display both riders' power on the same screen (as right and left). It might make it more difficult to do rider-based analytics, however.

Our team appreciates having power and/or heart rate data on the tandem. When we're on spirited group rides, I'll often tell my current training zone to my stoker such that she can match it. For those sort of rides, it would be even easier if she could see my power data on her screen, as well as her data. There have been times when I'm soft-pedaling to not hit the brakes, while she's motoring along; similarly, there are times that I'll be surging well above threshold to hang with the group while she's blissfully unaware of the effort.

Another good excuse for independent power meters on the tandem: we'll go for rides during which one person needs to do intervals, but the other is on a rest day. Having independent feedback is critical for those sort of rides.

Your post got my attention because we ride our tandem with spirited single bike groups at least 3 days per week......My stoker is not my wife and is just a female friend who is very competitive. I would only use the power meter on my pedals because she is already pushing as hard as she can but there are times she does not realize how many watts I'm having to push in order to stay with the fast pack and visa a versa there are times I'm barley putting any pressure on the pedals and she is pushing hard.......If she could see my watts displayed on her Garmin it would let her know when I need help without me asking.

alias5000 11-11-18 02:14 PM

Sounds like post #19 would be a cheaper solution to your problem, unless you want really fast responses.

Darth Lefty 11-17-18 02:31 PM

Iím curious how a power meter anywhere in the drivetrain could possibly differentiate two pedalers. Even in the pedals

alias5000 11-17-18 02:40 PM

Individual pedal power meters for each rider would do it, but post stoker crankset, you cannot differentiate anymore.


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