Power Meter Brands

thekooman

BB's baffle me... ive some knowledge.
So ive 2 Canyons with Shimano cranksets Pressfit and a Caadx with bb30 (ive 2 shims installed to take a Shimano crankset).

will this crankset work on Pressfit? what adapters would you need?

the BB30 on the Caadx is too noisy (constantly squeaky when FSA crankset was installed) but with the shims it isnt and the Shimano crankset.

bbolger

Crocked wrote: »

Kinda funny as you'd think most bikes ship with Shimano cranks so there'd be a bigger market there, but maybe not.

I think 4iiii could take advantage of this. They've started with their dual sided Shimano PM's, albeit at Dura Ace level, but maybe that's a marketing play to say their tech has tricked down to Ultegra and 105 level when available. Agree though, I would have thought Shimano gear is by far the majority.

Shimano themselves could obviously go the same way too.

https://4iiii-innovations.myshopify.com/collections/power-meters

dahat

€370 for a 105 crank arm with 4iiii, do the finest for the trainer.

Really tempted...

thekooman

dahat wrote: »

€370 for a 105 crank arm with 4iiii, do the finest for the trainer.

Really tempted...

that is great value

dahat

thekooman wrote: »

that is great value

Indeed and that's what I'm.going to upgrade my trainer power meter to before the Autumn. I smell a 40th birthday present of this in June!

Crocked

You'll have to add VAT and duty to that price though as it's shipping from the USA

bbolger

You can get the 105 from PBK or Evans for €400

Crocked

Ah, I thought they were a direct only seller.

Cond0r

Crocked wrote: »

It looks like the newer NG model with where the usb cover is positioned but in the tech it says 2% margin of error which would suggest rebranded type S

Needs FSA 386evo bottom bracket which would mean messing with bottom brackets which is always fun, especially if more than one bike.

Looks like p2m & a rotor 3D are still the simplest way getting a spider/crank PM that you can just directly replace your existing shimano cranks with at a "reasonable" price. Kinda funny as you'd think most bikes ship with Shimano cranks so there'd be a bigger market there, but maybe not.

I presume you mean including changing the bottom bracket to BB/PF30, if your frame allows it?

tunney

dahat wrote: »

€370 for a 105 crank arm with 4iiii, do the finest for the trainer.

Really tempted...

thekooman wrote: »

that is great value

a low price does not mean good value

dahat

tunney wrote: »

a low price does not mean good value

DC Rainmaker gave it a pretty good review from what i read, for indoor training it looks to be suitable for use.

Sarz91

dahat wrote: »

DC Rainmaker gave it a pretty good review from what i read, for indoor training it looks to be suitable for use.

I think what Tunney is getting at is the issue surrounding all single leg power meters in that they aren't consistent through different power zones or rider fatigue.

Chips Lovell

dahat wrote: »

DC Rainmaker gave it a pretty good review from what i read, for indoor training it looks to be suitable for use.

It's a left-leg only system. As DC Rainmaker says in his review:

But what does that mean from a technical standpoint? Well, at its most basic premise they simply double your left leg power. Of course, most of us have two legs, both of which output power. So for single left leg systems, they aren’t accounting for your right leg power individually. Rather, that gets ignored.

This means if your legs have an imbalance (very much normal), your total accuracy might be more variable. Further, it’s very normal for people to be variably balanced depending on intensity or fatigue. For example, I tend to be generally balanced up to about 315w (my FTP), but then beyond that, I become rather imbalanced. In the event that my left leg is weaker, that means my total power is being undercut on a Precision system. Whereas if left leg was stronger, my total power would be overstated. I’ll talk more about this later in the accuracy section – but I think it’s important to understand from the get-go.

dahat

Sarz91 wrote: »

I think what Tunney is getting at is the issue surrounding all single leg power meters in that they aren't consistent through different power zones or rider fatigue.

Yes, this i agree with but as a dual system would be out of budget a single leg system is what i will be getting if i do.

Sarz91

dahat wrote: »

Yes, this i agree with but as a dual system would be out of budget a single leg system is what i will be getting if i do.

If it's just for the turbo why not look at getting a used Powertap wheel?

dahat

Sarz91 wrote: »

If it's just for the turbo why not look at getting a used Powertap wheel?

Another possible option and these do pop up second hand pretty regular.

tunney

dahat wrote: »

Yes, this i agree with but as a dual system would be out of budget a single leg system is what i will be getting if i do.

Then why bother - you're not getting a device that measures your power output.

dahat

tunney wrote: »

Then why bother - you're not getting a device that measures your power output.

It will give a reasonable guide to power output which at a starting point i'm happy with. I have a Stages on my race bike and am finding it a useful tool while well aware of its limitations.

godtabh

Seems legit

https://m.aliexpress.com/s/item/32798182129.html?trace=wwwdetail2mobilesitedetail&productId=32798182129&productSubject=32798182129&shortkey=buENnaEj&addresstype=600

thekooman

godtabh wrote: »

Seems legit

https://m.aliexpress.com/s/item/32798182129.html?trace=wwwdetail2mobilesitedetail&productId=32798182129&productSubject=32798182129&shortkey=buENnaEj&addresstype=600

jaysus... would ya risk it!

godtabh

thekooman wrote: »

jaysus... would ya risk it!

Nope

dragratchet

thekooman wrote: »

jaysus... would ya risk it!

"The above picture is the product of the finished product picture, you can see the sticky parts of the laser after the fire"

... id have reservations about their manufacturing process :eek:

Chips Lovell

The issue with single-sided power meters is that there's two many unknown variables for them to be useful.

Here's a file from a race I did last year.



As you can see, the L/R shifts around a fair bit, moving between 50/50 and 60/40, with a few spikes even larger than that. If I'd been using a single sided power meter it would have largely moved between accuracy and lowballing my numbers, with odd overstatement.

Now, here's a better illustration, a file where I did three 5 minute hill intervals.



What does it tell you (aside from the fact that I did the first one harder than the other two)? That for sustained Z5 type efforts my left leg was dominant, but for anything below that I seemed to favour my right.

What does this mean then for using a single-sided power meter? Well take a hypothetical rider who, like DC Rainmaker, has a largely 50/50 balance up to and including FTP. So they get a single sided power meter, do a proper test and find out they've an FTP of 350w. They then go set their zones based on this number.

The problem then is if their balance varies based on intensity or fatigue. Say our rider decides to do 4x 5 minute Z5 intervals. According to the zones he's worked out, that's something like 370w to 420w.

Our rider decides to attempt to average 400w for each interval. But, what he doesn't know is that above FTP, his L/R balance is more like 55:45. Because the left side power meter just doubles left sided power, he's doing 200w with his left leg to display an average of 400w. But he's doing 245w his right leg, meaning is real power output is more like 445w, which is well into Z6. What happens? He goes too hard and can't complete the set.

Or it could be the case that his L/R balance is 50/50 when he's fresh, but as he fatigues it drifts in one direction, meaning he starts actually doing 400w but then has to up his effort beyond 400w as he tires in order to keep the display reading 400w. After a few failed attempts at a set, he's going to start lowballing the initial intervals in order to sustain (what he thinks) is the same level of effort at the finish.

€400 is serious cash and I don't think you'd be getting much in return. With that amount of uncertainty, i can't see it providing any advantage over perceived effort or HR based training.

joker77

How'd you set up the graph in Golden Cheetah?

Chips Lovell

joker77 wrote: »

How'd you set up the graph in Golden Cheetah?

Go into the activity, and click on the Ride tab. Then open "All Chart Settings" at the top. There go into the Curve tab and only tick Power and L/R balance. Then back into the chart and at the top, uncheck "Stacked" and that'll put overlay the L/R balance onto the Power.

Beasty

I've been focussing on L:R balance quite a lot recently as I'm suffering from sciatica which can affect either leg (although usually just one at a time). This is on a Wattbike which provides very accurate measurement.

If I look at my historical records I can see I'm at 50:50 or 49:51 (either way) very consistently. However I'm currently finding (when I don't focus on this particular issue), that when I'm warming up it will typically be something like 47:53 - meaning my right leg is putting out over 10% more than my right leg. During efforts it's 50:50, but during a cool down it's around 42:58 - a difference of around 40% :eek:

That helps highlight the importance of having something that measures output in each leg rather than just one, and also in my case is very useful to help me understand the potential impact of this injury, and equally how I can need to focus on one leg to try and improve my all-round performance. It can also give a pretty good insight as to how my back injury (that's the source of the sciatica) is progressing. Hence I would certainly be very sceptical of data from just the one leg

mossym

Beasty wrote: »

I've been focussing on L:R balance quite a lot recently as I'm suffering from sciatica which can affect either leg (although usually just one at a time). This is on a Wattbike which provides very accurate measurement.

If I look at my historical records I can see I'm at 50:50 or 49:51 (either way) very consistently. However I'm currently finding (when I don't focus on this particular issue), that when I'm warming up it will typically be something like 47:53 - meaning my right leg is putting out over 10% more than my right leg. During efforts it's 50:50, but during a cool down it's around 42:58 - a difference of around 40% :eek:

That helps highlight the importance of having something that measures output in each leg rather than just one, and also in my case is very useful to help me understand the potential impact of this injury, and equally how I can need to focus on one leg to try and improve my all-round performance. It can also give a pretty good insight as to how my back injury (that's the source of the sciatica) is progressing. Hence I would certainly be very sceptical of data from just the one leg

a lot of the discussion, in most of the power threads has revolved around whether one sided were accurate or not based on variances on the LR balance across different effort levels, the presence of variances would make one sided systems unreliable. think it's fair to say it was a heated discussion.

much like you, if i look back over my rides i see significant variation in the balance depending on the session, and my experience has been that anyone with a dual sided system has seen the same.

some refuse to believe all that as they can't justify the higher cost of a dual sided system and need to believe the cheaper system is accurate. however, spending 400 euros on a non accurate/(and so non working) system is a bigger cost than 800 on one that works.

it's one of those neverending arguements though, i don;t ever see it being resolved.

thekooman

new Garmin Vector 3 / 3s looks good
http://www.bikeradar.com/road/news/article/garmin-edge-1030-garmin-vector-3-features-and-prices-50658/

no pods and no need to torque which is great. just sold my first Gen Vectors which have been great for 2.5 years of work (hard work as well! ).

harringtonp

thekooman wrote: »

new Garmin Vector 3 / 3s looks good
http://www.bikeradar.com/road/news/article/garmin-edge-1030-garmin-vector-3-features-and-prices-50658/

no pods and no need to torque which is great. just sold my first Gen Vectors which have been great for 2.5 years of work (hard work as well! ).

https://www.dcrainmaker.com/2017/08/hands-on-garmin-vector-3-power-meter.html

seanin4711

Power 2max ng eco for me
489 for arms and rings.
Crank based
FSA power box similar spec and price.