[Closed] Power meters

road or mtb ?
Depends what you want it for? racing or just training?

I use a Quarq MTB on the race bike

power tap Pro + on the road bike built onto one of their rims.

Pro's >Quarq

>can use any wheels
> no weight penalty
> BB bearings are standard

Cons

>Price
> if you change ring sizes you need to send it off for re-calibration

Power tap pro+ (good)

>less in price
>can get a g3c option which is much lighter than pro+
>great training wheel

Cons>
bearings are rubbish if UK conditions
your "supposed" to send it back to get bearings changed as you "may" damage torque tube (voids warranty changing it yourself i think)
>weight

I like both, but would always rather have a crank based system if i was planning on racing! otherwise powertaps are great.

Have you thought about renting one first to see if it is for you? Also a power meter can be a great training tool giving loads of information however you may need the advice of a coach on how to use this information for training , setting goals etc.otherwise they can be just an expensive toy.

Yes as Ed says, you need to know how to use power otherwise it's just an a expense spedo.

there are some great books to help if you plan to do it your self!

unless you're a pro, riding to a power level for sustained periods then a power meter is like a bankrupt man renting an accountant to tell him how bankrupt he is.

get a coach, far better return on investment

Stages power crank on my race bike and a PoweCal HR based monitor on my commuting bike (and mtb if I can be bothered).

I find the power meter useful as a means of preventing over exertion in races and climbing - so you can stick to a steady 300W climbing a hill, rather than sprint off and blow up. In a race, I've used it to tone down effort near the front, but usually everything is too fast to read it.

I like the PowerCal for commuting, it is a measure of my effort, and adds something to the ride. But I haven't calibrated it yet.

I suppose I just want to quantify my riding, ie see the progress and plan for the future etc.

I have a loose racing schedule (xc mtb) and no grand plans, I just want to be fitter and faster!

I don't want to spend mega money either, so I'm thinking hub-based with my current Garmin 800/7900 crank

fr0sty - Member

I suppose I just want to quantify my riding, ie see the progress and plan for the future etc.

I have a loose racing schedule (xc mtb) and no grand plans, I just want to be fitter and faster!

I don't want to spend mega money either, so I'm thinking hub-based with my current Garmin 800/7900 crank

as you won't know what to do with the information the device provides nor how to best train with it please may I suggest again the answer to the question is a decent mtb specific cycling coach

Used Powertap hub would be my first call then. Just choose your wheels carefully, because you can't change them.

The PowerCal is really cheap, and is better than HR. BUt it itsn't a REAL power meter (distribution of power is too narrow compared with a real meter). But it is very cheap (comparatively, £80).

Given your details and goals then I'd agree with the others and say get a fitness test, (VO2 max/lactate/HR Zones), done with a coach who is also qualified to create a training plan for say 12 weeks based on the results of the test and the equipment you have, (HR monitor).

Do the training, learn about your body, repeat the tests, see an improvement, then assess the need for a power meter.

I use a PowerTap, its taken my racing results up a level, however it took me a couple of seasons of proper training without one to understand my body and the numbers I was seeing.

Sounds like something along the lines of TRIMP or Strava Suffer score might be better for you.
Gives you a number to quantify your rides, although won't be as accurate as power it is usually pretty good.

Pros and cons of training by power, most people do not use power meters to the extent they are designed.

I'll def be following the trainer advice and will be making some phone calls this afternoon, as well as posing a wanted ad for a hub system.

This is my first season riding MTB and my first season riding competitively at all, with little bits of ad hoc training preparing me (intervals/hill sprints etc).

What I want to do is develop a training plan for the coming winter with a view to riding a full season of races in 2014.

I have a PowerTap, to be honest I don't really train any more, just ride my bike, but it's nice having the numbers to quantify how unfit I am!

If I was buying now I'd probably get a Power2Max - sell your 7900 cranks and you'll recoup a fair bit of the cost. The cheap PowerTap is heavy, and I certainly notice it. Like all these things it's probably psychological more than anything, but the bike does feel better when I fit a comparatively lightweight rear wheel.

I have a powertap and use it a lot for training. Really helps me as I don't have much time to train so tend to do a lot of interval work to power targets on a turbo. By using a powertap I know that the training I'm doing is at the right intensity (HR is fine when just out on a long ride, but not that good for proper interval sessions.) As I've become better at understanding the data it generates it's been a help with avoiding overtraining too.

If you do get one I'd recommend getting a good books on power based training. There's one by Allen & Coggan and another by Joe Friel (I think the latter references the former a lot and they are complimentary.)

It's handy to have the powertap for the turbo as I can easily swap it between my turbo bike and mrs blobby's turbo bike. Ideally though I'd have a crank based one on all my road bikes 🙂

Slightly OT but i was watching a stage recently with Wiggins where they stated he'd changed bike and didn't have a power meter making it a lot harder to ride.

I assume that means from a percieved effort, actual effort context. But you'd have thought by this stage in his/pro-riders careers they'd know when they're on the pace, off the pace, maxed out etc etc ?

He changed bikes, (using the excellent self parking system in all Pinarello's), and his new bike had different gearing meaning he was over geared for the very steep climb to the finish.

Not sure I saw/read anything about a power meter. Seems a little too reliant on them if that's a real excuse.

I assume that means from a percieved effort, actual effort context. But you'd have thought by this stage in his/pro-riders careers they'd know when they're on the pace, off the pace, maxed out etc etc ?

I'd have said that until getting a power meter. He'd probably have a very specific power target that he knows he can sustain on a specific climb. You don't have to be many watts over that to get into trouble. Perceived effort is fine, and I'm sure he can judge it much better than most, but if you want to ride to your limit then I think if you're judging it by PE it'd be very easy to be a few watts under or over.

Edit...

He changed bikes, (using the excellent self parking system in all Pinarello's), and his new bike had different gearing meaning he was over geared for the very steep climb to the finish.

I don't doubt that. I am surprised a pro team like sky didn't have an exact copy of whatever bike Wiggins was currently riding for him to swap to.

if you're training on a turbo - you certainly don't need one to train with power.
look at something like trainerroad.

I am surprised a pro team like sky would have an exact copy of whatever bike Wiggins was currently riding for him to swap to.

You'd be surprised if they did, or you're surprised they don't? I'd half expect them to. Cancellara has 3 completely identical Trek Domanes.

Agree it's a little odd if that's a genuine excuse!

I am surprised a pro team like sky didn't have an exact copy of whatever bike Wiggins was currently riding for him to swap to

I was too, however that was what was generally reported, inner ring was an standard 38 and not what was on his race bike.

if you're training on a turbo - you certainly don't need one to train with power.
look at something like trainerroad.

Trainerroad is good, I use it a lot, but if you don't use a power meter you just get an approximation of power based on wheel speed and speed/power curves for your specific turbo. I tried using the virtual power on my turbo and I get quite a lot of variation between the power it calculates and what the power meter reports. The virtual power reading can vary considerably for instance on the amount of pressure in the tyre and how firmly the turbo is pressing against it. Can be a few tens of watts over or under.

Edit: Sorry njee20, ninja edit on my last post 🙂

if you're training on a turbo - you certainly don't need one to train with power. look at something like trainerroad.

A turbo or rollers is the perfect place to train with power! Consistant, no hills, expect when you want them, no traffic, nothings better

Apparently Sky are short on SRM's, so much so that they swap them between bikes rather than every bike having one.

Training with power on the turbo is (IMO) superior to using just a HRM. On the road its a lot harder to maintain constant power, it takes quite a bit of training to be able to do so. You need to have your zones worked out for you, lactate threshold and so on. Otherwise it just becomes a posh 'speedo' and therefore doesn't have much use

Trainerroad is good, I use it a lot, but if you don't use a power meter you just get an approximation of power based on wheel speed and speed/power curves for your specific turbo. I tried using the virtual power on my turbo and I get quite a lot of variation between the power it calculates and what the power meter reports. The virtual power reading can vary considerably for instance on the amount of pressure in the tyre and how firmly the turbo is pressing against it. Can be a few tens of watts over or under.

But the point is - the consistency and not the difference between real world and turbo world measurements.

I was too, however that was what was generally reported, inner ring was an standard 38 and not what was on his race bike.

Any reports on what happened to his bike? Heard it was some sort of failure of the Di2. Someone forgot to charge the battery? 🙂

But the point is - the consistency and not the difference between real world and turbo world measurements.

Yes. My point is with trainerroad virtual power it can be difficult to get consistency as it's based on quite a few setup variables. Still a great bit of software though.

His replacement bike didn't have the mount for the SRM on it so he bunged the head unit in his pocket, not sure whether it actually had SRM cranks on (it's those that Sky don't have a vast surplus of rather than the head units...). I think he'd have struggled to pair them up anyway whilst trying to chase down a race-winning break on a steep climb. As has been said, he'll be able to judge his perceived effort much better than most but the whole marginal gains thing means with a power meter he can ride to very specific watts not just perceived which will be less accurate (and more prone to psychological effects).

Using a power meter allows you to measure you attempt through, which results in better quality services, enhanced fitness, as well as a better moving competition attempt come competition day.