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Okay so a couple questions:


Is measuring power all its cracked up to be?  Is it better than using an hrm for training?  How accurate are polar's power-measuring-attachments that measure power using your chain compared to sumthing like powerTap? 


Would i be wasting my money to buy one of garmin's bike gps?  has anyone used one of them?  Do they giv height profiles of a course, etc?  Do you hav to buy maps seperately?  Does it work like a polar hrm would work?



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I hope you find the article below of interest.

Polar Power is a little tough to set up well but does work and although inconsistent in some gear combinations or on a trainer, is reasonably repeatable  - for a little more money however a PT std is a better option



should cyclists train with a power meter?




It is no co-incidence that most of the world?s top cyclists have

achieved their results with the help of power based training. Almost every

recent top cycling performance has been aided by the use of power meter

training technology, including Tour de France wins, one hour records, track

records etc




RPE (rate of perceived exertion) and HR (heart rate)

monitoring have certainly gone a long way towards improving the quality of

cyclists? training in past years but both have major limitations that can

inhibit training and racing efficiency




RPE in most cases is too unreliable (we are too

subjective in its use) and the only way of saving data is in our own brain?s memory!




Heart rate monitors have served athletes very well

in providing an indication of the load that the body is under, however, the

only accurate information that a HR meter does give us is how hard your

heart is working


There are numerous limitations and unknowns

associated with training with heart rate alone, being subject to numerous environmental

and physiological variables (e.g., temperature, humidity, hydration status,

altitude, overtraining, lack of sleep, nervousness, and upward

"drift" as exercise progresses)



also responds too slowly to changes in effort (workload). This is not a problem

for steady state (LSD) efforts but the ?lagging? response to change in workload

is not ideal for interval training, especially short duration efforts





monitoring, in comparison to RPE and HR monitoring, in the words of power guru,

Andrew Coggan ?.. ?objective measure of exercise intensity, and as such directly

determines physiological and perceptual responses to exercise, so training by

power provides immediate and quantitative feedback on the intensity of effort. 300 Watts is 300 Watts, no matter how hot, windy, or

hilly it is, or what your heart rate is ? though it may "feel" easier

or harder depending on various conditions?





top South African cyclists are now realising the value of ?power based? training

and it is certainly going to be the next wave of technology

to revolutionise cycle training globally and in particular, here in cycle crazy

South Africa.




The best known of South African cyclists using

power meter technology is Robbie Hunter (and the Phonak team) Recently,

Powertap fans Shan Wilson and Brandon Smith were the first South African team

home in the gruelling Cape Epic 8 day MTB stage race




Power based technology has definitely given

cyclists a huge knowledge base about the unique functioning and

recovery of their own bodies when subject to the stress of hard training and










The main advantages for training with power are as





1.  Training with a power meter gives you a

complete record of your effort. 


A power meter records all data from a session or race, including

your effort from a cardiovascular viewpoint (heart rate), and from a muscular

viewpoint (watts). Most powermeters will also record cadence (leg rpm), speed





2.  Monitor changes in Fitness. 


Know with certainty whether your fitness is improving and when you

have reached a peak. Avoid over training and overreaching




3.  Analyse your Race 


A power meter can help you better analyse your race. You can easily see when

you used too much energy in parts of the race that weren't decisive. Did

you make a tactical error in a race, but didn't realize it? By

analysing your race data you can learn volumes about the way in which you can

improve your racing and training




4.  Enhance your indoor training. 


Indoor training is no longer a second rate substitute for ?rainy day? training.

Power meters fitted to your own bicycle allow you to execute identical sessions

to those on the road. In fact many quality sessions (and testing in particular)

are better executed away from variables like weather, traffic etc.




5.  Pinpoint your strengths and weaknesses. 


With a power meter, you can analyse your performances and training to find out

what your natural talents and weaknesses are. You then have the knowledge of

where to improve and the strengths that you can capitalise on




6.  Accurate feedback to your Coach! 


A power meter doesn't lie!




7.  Achieve your physical potential! 


A power meter will allow very accurate execution of intervals and training

sessions, in particular, execution of short, intense intervals. There is no

guesswork, the cyclist knows exactly what effort to put in eg 10 x 2min @

450watt. Such a session is typically impossible to execute properly with heart

rate feedback alone




8.  Improving aerodynamics. 


Most of the energy expended by a cyclist (at speed) goes into

overcoming wind resistance. Body position is the single greatest factor in

determining your speed while riding at a specific power output. Why risk the

disadvantage of a poor position when you can measure your aerodynamics and

discover your fastest position!




9.  Superior Pacing of efforts. 


A power meter allows you to calculate and pace your effort better in all of

your interval workouts, hill climbs and time trials. When you know your

threshold power, you are better equipped to race to win (rather than ?blowing?

while trying) or to avoid being dropped by the bunch.




10.  Optimisation of cadence. All

cyclists will have their own unique optimum cadence. Use a power meter to

establish this




11.  Accurate and regular testing 


A power meter allows you to test on a monthly basis, so you can quantitatively

see what areas you have improved on and what still needs work. By testing

regularly, you can better understand your potential for improvement and better

avoid overtraining.




12.  Record your training data every few



It's the true diary of all information for every ride. You will

know what you were doing almost every second of all races and training





13.  Coordinate your sports nutrition for best



Knowing how much work (in kJ) you do in training allows you to plan your meals

with accuracy! You will recover faster and be able to train harder sooner. You

will also be able to plan to reach your ideal physique by eating enough to

supplement or maintain your muscle mass.




14.  Highly efficient planning, control and

execution of training.


Train efficiently so that you peak at your goal events. Every top

cycling performance has been aided in some way by the use of power meter







--- oOo ---

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Chris, I've got the Legend CX , colorscreen and 64k memory chip. Not the 301's with a hrm.




You get the first map with the gps. Lets say the SA streetmaps4. Its only the streets. You have to buy the "topo" one, were you will see the landscape "topografies".




The gps can't take the whole map, so you choose sections of the map to download. Than you track were you ride, transfer it back to the map and start gathering different trail rides etc.




The gps is spot on with speed / altitude etc. Its a "nice to have".

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Thanks for the power article - very helpful.


As for gps, are the maps expensive and do they allow you to download a big enough area of the map so that you can do a long distance ride (ie. up to 200km odd) without running out of map?

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I'll give a big vote for the value of power training. There's more demonstrable value in my Powertap than any wheel or frame upgrade that I've ever bought.

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Power training is great for cycling.

But, if you also run/swim/paddle/ski, etc, etc then you need to think about something that can support those modes.


I have used a Garmin 301 for 2 years for monitoring of heart rate, speed, pace, elevation, climbing, route....the 301 has flaws but they are masked by its staggering abilities. Take a look at


I believe newer models ship with the high-detail Streets software now.

You can't actually upload maps to the sports GPS - only to the higher-spec models. However, you can upload Routes and waypoints so it can be used as a "real" GPS. The newer models (305, etc) also support cadence.


P.S. Garmin's Training Centre software is mediocre. Try SportTracks (Zonefivesoftware.com). It's free. You'll never look back.

P.P.S. Check out the GarminF forum on Yahoo.

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Yes, they are. I think the topographic cost about R1700.




You can upload pieces. See the pic , those grey lines is a block, as long as you don't "pick" more blocks adding to more that your memorycard , its OK.




You can work on a province @ about 10mb. so more than enough map detail.





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Thanks again to all replies


The colour maps etc look great but i think a bit out of my budget (as too are the powertaps and similar):(    With the edge 305 / 301 can you upload an "altitude course" so you can see eg how much more of a hill to climb as you climb it?  Do you find the 100 waypoint limits you?


Am i gonna hav any problems if i buy a gps in america?
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Last time I spoke to Garmin SA they said they were considering bundling the new Forerunner units with the street maps as standard. If you buy in the US, you won't have this option. I would also check beforehand about how this would affect a warranty claim.


You can't upload maps to a Forerunner, but you can view them in Garmin's Mapsource software (free download from the Garmin site.)


When I got my 301 in March 2005 it came with just the base map. This is a world map that goes down to about trunk road level. That equates to about the M5/M3/Main Rd/R102 in Cape Town or say the Champs Elysees in Paris. Resolution is OK.


With the Streets software you can plot routes, and set and manipulate waypoints, with accuracy to within a few metres. I obtained the Streets software separately, by the way.


You can't do an altitude course per se. What I do is set a waypoint at the top of the climb. I then tell the GPS to "Goto" the waypoint and it will point the way and count down the distance remaining (and time, based on your average speed; and elevation, if you have put in the elevation when setting the waypoint). Of course this is all "as the crow flies", so if you want more accuracy you simply create a route with as many waypoints as you like up to 100, and upload the route to your Forerunner.


Does the 100 waypoints limit one? Er... no. You can save your waypoints to Mapsource anyway and upload specific ones when you need them.


PM me if you'd like some screenshots of my SportTracks tracks.






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Ask yourself what you want the gadget to do for you, and what you want to get out of cycling.


If you want it 'cause it's a cool gadget and it will motivate you to ride more, well then it's prolly worth buying the sucker already.


If you want to use it as a training tool, you will need to learn how to interpret the data that it presents and use that data as an input into the structure of your training programme.  The word "structure" is a biggie.  If your training currently consists of going out training with your buds and trying to make one another hurt, all that a power meter will do is add some numbers to what you are doing.  To really get training benefit (which is not the same as enjoyment, and may even be the opposite) you will prolly be riding alone a lot more 'cause your buds will not be doing the exact same workout as you are doing.

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legend. no its only on CD.




Anyone can download that ce to the PC "Mapsource", but only the original buyer have a key (code) to enter in a GPS. You can only unlock one cd to a spesific GPS and serial number




So, when you buy the gps you get one standard cd (say: sa maps 4), Now you track your routes on the gps, you can plot that to any of the "illegal" maps on the PC, but you cannot load a "illegal" map back to the GPS.




Remember, you have to download a map on your GPS as well (or oiece of it). You will only be able to load streetmap 4.




A lot of guys working with me are 4x4 freaks, Every year about 10+ of them goes of to Moz, botswana, Suid Wes etc. They got every dam map available, even the new concep were you buy the maps for R30 (i think) but you upgrade every year the map for R250 +-.




so, I'e got those on my PC, and show my routes on different ones.




Also note, that different maps got different points of interest.




Even the cafe in the nabourhood. Its amazing the detail on these maps.

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