Mtb with power meter

[Imtb]

Thanks string bean, the ergomo is way out of my price range at the moment. I will just have to be careful about riding in the rain - I have two bikes and so will use the one to train with the power meter and one for racing and riding in the wet. I have read alot of good things about the Powertap as well - so guess I am abit confused now

[Imtb]

Bottom line is, I want to train with a power meter but at the end of the day it is what one can afford. Upgrading my bike won't make me a stronger rider, but I think I am right in saying that training with power is the way to go - and if a PowerTap is an option for a mountain bike and is the cheapest option, I guess I will just have to pick and choose the weather I ride it in - if thats possible. What do you think string bean - its either no power meter or the PowerTap.

[BikeMax]

 

Don't do it imtb' date='you are just wasting your money.If you realy have made up your mind i would defenately go with the ergomo and NOT the powertap.Have ridden both and the ergomo is far more waterproof than the powertap.In fact on my road bike the powertap stops working if i ride in the mist let alone riding in the rain.The first little puddle you ride in on your mtb you might as well throw the powertap away,even if you got one for cheap it's still money that will be wasted.Rather take the money and upgrade your mtb.

[/quote']

 

Although this is only an "opinion" I feel that it is misleading and factually incorrect.

 

The PT has been very waterproof since the design was reviewed about 2 years ago and all the interbals dipped in a wax coating. I have had various models for 4 years and have never had a water ingress issue.

 

If you have an issue with your PT then please give Adrian a call and discuss it as you clearly have a problem if what you say is happening

 

The Ergomo may be pretty weatherproof but it has some serious issues regarding accuracy and consistency - this I found through personal trials but has also been backed up by a recent study in the IJSPP that showed that the Ergomoappears "less valid and reliable then SRM or PT systems"

 

 

[Imtb]

Having read a large number of comments on cyclingforums.com I would have to agree with you Peter.

[1kTT]

Hi Peter,

 

Could you please post a link to the study that shows that the Ergomo is "less valid and reliable then SRM or PT systems".

 

Thanks,

 

[BikeMax]

 

 

Hi Peter' date='

 

Could you please post a link to the study that shows that the Ergomo is "less valid and reliable then SRM or PT systems".

 

Thanks,

 

[/quote']

 

Here is the abstract as posted on wattage forums;

 

IJSPP, 2(3), September 2007, Copyright © 2007

 

Validity and Reproducibility of the Ergomo®Pro Power Meter Compared With the SRM and Powertap Power Meters

 

S?bastien Duc ; Vincent Villerius; William Bertucci ; Fr?d?ric Grappe

Full Article         Table of Contents for Vol. 2, Iss. 3

 

Abstract

Purpose: The Ergomo?Pro (EP) is a power meter that measures power output (PO) during outdoor and indoor cycling via 2 optoelectronic sensors located in the bottom bracket axis. The aim of this study was to determine the validity and the reproducibility of the EP compared with the SRM crank set and Powertap hub (PT). Method: The validity of the EP was tested in the laboratory during 8 submaximal incremental tests (PO: 100 to 400 W), eight 30-min submaximal constant-power tests (PO = 180 W), and 8 sprint tests (PO > 750 W) and in the field during

8 training sessions (time: 181 ? 73 min; PO: ~140 to 150 W). The reproducibility was assessed by calculating the coefficient of PO variation (CV) during the submaximal incremental and constant tests.

Results: The EP provided a significantly higher PO than the SRM and PT during the submaximal incremental test: The mean PO differences were

+6.3% ? 2.5% and +11.1% ? 2.1%, respectively. The difference was

greater during field training sessions (+12.0% ? 5.7% and +16.5% ?

5.9%) but lower during sprint tests (+1.6% ? 2.5% and +3.2% ? 2.7%).

The reproducibility of the EP is lower than those of the SRM and PT (CV = 4.1% ? 1.8%, 1.9% ? 0.4%, and 2.1% ? 0.8%, respectively).

Conclusions: The EP power meter appears less valid and reliable than the SRM and PT systems.

 

BikeMax2007-08-19 11:34:20

[Craven]

Hey Peter

Have you seen this yet?

http://quarq.us/index.php?option=com_frontpage&Itemid=1

Not out yet but it certainly looks interesting and has some very nice features.

 

[BikeMax]

 

Hey Peter

Have you seen this yet?

http://quarq.us/index.php?option=com_frontpage&Itemid=1

Not out yet but it certainly looks interesting and has some very nice features.

 

 

Hey Dan - hope all good.

 

We were introduced to these guys by Hunter Allen when he was over - it looks like a very interesting product indeed - cant wait to see more.

 

Hope that SRM is still in good use..

 

[Imtb]

Anyone out there have an idea on what averaged priced wheel to get to build the PowerTap pro onto - for a mountain bike. What should I be looking for bearing in mind that I won't be using the bike for racing, (will do a few races to get an idea of my power during a race) just for training.

[1kTT]

 

 

Hi Peter' date='

 

Could you please post a link to the study that shows that the Ergomo is "less valid and reliable then SRM or PT systems".

 

Thanks,

 

[/quote']

 

Here is the abstract as posted on wattage forums;

 

 

Thanks, I am surprised at the results because I have seen a number of other tests where the SRM & Ergomo's outputs were for all practical (not laboratory) purposes identical.  A quick google search will bring up lots of results but here is one:

 

http://www.thebikeage.com/ergotest.htm

 

You have got me a bit worried, are you saying that an Ergomo is not accurate enough to use for power training ?

 

 

 

 

 

[BikeMax]

 

 

Hi Peter' date='

 

Could you please post a link to the study that shows that the Ergomo is "less valid and reliable then SRM or PT systems".

 

Thanks,

 

[/quote']

 

Here is the abstract as posted on wattage forums;

 

 

Thanks, I am surprised at the results because I have seen a number of other tests where the SRM & Ergomo's outputs were for all practical (not laboratory) purposes identical.  A quick google search will bring up lots of results but here is one:

 

http://www.thebikeage.com/ergotest.htm

 

You have got me a bit worried, are you saying that an Ergomo is not accurate enough to use for power training ?

 

 

 

 

 

No - I don't think that.. but I do think it has some issues that affect it's consistency of reading.

 

I found exactly the same as the study when I tested my unit - it consistently over read at lower powers but got closer and closer towards and over threshold. I think the unit is so ultra sensitive to installation and maybe even BB material, that it is just so dificult to isolate any issues.

 

In a race I did on the road, with lots of variability (lots of high power and lots of very low) it was 30w higher than my PT for the duration of 2.45.

 

It odes appear to be pretty consistent though so really only an issue if comparing with other non Ergomo data.

 

I believ they have recalled a number (if not all) units sold in SA back to Germany - so the issue may have been solved.

 

[1kTT]

thanks Peter.

 

I know that some of the early Ergomo installations has issues with the bb not being faced 100% so gave some inacurate readings.  Also I just did a firmware upgrade that seems to have cut out the one or two high power spikes I used to get.

 

[Photo Fairy]

 

Any other mountain bikers that train with a power meter?

 

Speak to Cruxpearl, he has SRM on his MTB