To power or not to be?

I’ve been debating on which power meter to get for  my bike.  I’m putting a lot of thought into it because it could be a costly mistake if I go with the wrong unit, but I worse case scenario I could turn around and sell it and lose little if any money since they sell like hot cakes on ebay, even old junky ones fetch more then they’re worth oftentimes, for a $100-200 hundred dollars more you could just buy a new unit in many cases, so you have to figure out before hand what a unit costs new, and if takign the risk on a used unit that might have issues is worth it.  You shouldn’t have to spend more then a few hundred dollars for an older wired unit, if you’re patient you should be able to find one in your price range on ebay, they last for many thousands of miles and can be serviced too so don’t worry too much about it.

I’ve trained a little bit with power in the gym on the stationary expresso bikes, and I love it, it gives me instant feedback to measure my effort, it’s very simple either you’re putting out the watts or you’re not, speed, wind, grade, none of that matters, it’s like a lie detector. Heart rate is good, but still a subjective measurement, but watts don’t like, and heart rate combined with watts is amazing and tells you so much more about what’s going on, there’s just no comparison.

So I’ve been planning on getting a powermeter this season and have been shopping around educating myself, I’ve narrowed it down pretty much to a powertap, and from there I’m just trying to figure out which model, there’s quite a bit of choices esp. since things have changed greatly in 2009 at Saris

PowerTap Options

1. Old wired SL or Pro unit
2. 1st generation wireless 2.4 unit
3. New 2009 Pro wireless units that are +ANT +Sport i.e Garmin 705 able
4. New 2009 SL+ wireless units that are +ANT +Sport i.e Garmin 705 capable

* And you can get any of these with or without a wheel, or head unit, I’d recommend to get a complete kit with the hub built onto a wheel as you’ll probably have to wait 1-2 weeks and paying $100 more to have the the wheel hub replaced. Also with an extra wheel you could get a matchign front and then have different tires on each set of rims for different weather, or if you have race wheels, unless of course you wanted to race with the powertap, then you’d want it mounted on your nice wheels.
*You can find used units on ebay etc. or buy a new unit

There are some other cheaper new 2009 models but they’re heavier, not wireless and or lack features, I don’t find them as much a value personally.

So let’s get into some details and pros and cons of each, for me it’s basically coming down to which features am I willing to pay for

Cost

1. The cheapest is to get a used wired powertap off of ebay, many of them will come on a mavic open pro rim so you don’t have to spend time or money getting a wheel built, and
   have the option of having training vs. racing wheel, but once you ride with power you’ll probably want race data too, esp. since your real threshold and max watts numbers will come out, it’s very hard in training and testing to hit the same numbers you in a race.
2. The next cheapest option is a used 2.4 wireless unit from last year or earlier.
3. After that then a 2009 Pro+
4. The most expensive option is to get either a new SL+ or SLC+ 2009 already on a wheel, or on a set of race wheels like a zipp 404 etc.

Functionality

In the end you want to be able to collect all the data you need

1. Watts
2. Heart rate
3. Cadence
4. Speed

You need to watch out because not all units work the same and many of the older units are notorious for having broken heart rate monitors, luckily thought Saris is excellent when it comes to customers support and will often just replace the defective head units no questions asked.

If you get an older wired unit, you’ll want to make sure it comes with a heart strap, and HR is working, and it comes with cadence. If it doesn’t don’t worry as some of these items can be ordered by themselves, just take it all into consideration when comparing items in auctions etc.  Some auctions will include both a front and rear wheel, some will come with or without the head unit, you have to look carefully at them when comparing.  Other good questions to ask are

1. When was the unit last calibrated
2. How many miles on the unit
3. Are the bearing in good shape, are they ceramic?
4. Does it come with a working heart strap?
5. is it a coded or uncoded heart strap and head unit?
6. Is the wheel in good shape is it round and true
7. Has the wheel been crashed at all, this is more important for expensive wheels like zipp 404 etc. that you might buy with a powertap

The used 2.4 wirless units can also be a great value, the biggest different between a new and used wirless unit is that you won’t have the +ANT +Sport ability,

Upgrade an old wireless unit to +ANT

for $100 you can order an updater kit from Saris and convert the 2.4 to +ANT so it will talk to your +ANT type units like the Garmin 705.

Which is better wired or wireless?

I’ve found out that both work equally well, there are some pros and cons to both depending on where you ride and how many bikes you have that
you’d be swapping wheels out on etc. or if you ride in inclement weather often.

GPS and power together like peanut butter and Jelly
GPS, while we’re talking about the Garmin 705, you might be asking so what? Well, having the ability to combine GPS with your ride data watts will give you the ability to see where exactly on your ride plotted on a map you where putting out which watts, so if you did a long ride with lots of climbs, or a race etc. you’d be able to see exactly where you did what effort. You can sort of figure this out by looking at your powertap files by trying to compare a major hill climb and time etc. to and guessing where you where on the course, but with the Garmin 705 you’d be able to download GPS and watts data.

Wired PowerTap GPS Bliss

I made an interesting discovery the other day I found out that if you already have a GPS unit like a Garmin extrex etc. and can download a .gpx file etc. You can merge this file with your wired powertap data with the right software and combine GPS and power data very much like a Garmin 705 does.
So if you want the same data but want to save oh say around $1000 between having to buy a wireless +pro +ANT type unit and a $500 garmin 705 and you already have another GPS unit you can download from here is the solution

1. Get a used wireless Powertap for $300-600
2. Get a copy of TopoFusion $60
3. Buy a handheld GPS unit like an extrex etc for around $200 if you don’t have one

Check out this page for more details on how to do it http://www.topofusion.com/power.php

So essentially there’s little difference in actual data collected in a used wired or wireless powertap vs. a new one with the +ANT.
So unless you have some compelling reason to need to have  the +ANT and Garmin GPS unit both I don’t see it being worth spending $1000-1500 more for it.

Reasons that might make it worth it.

1. You already have a Garmin 705
2. You Plan on getting a Garmin 705 anyway, then you might as well get the powertap that works with it.
3. You race and want to save wait by not having to carry both the powertap wired head unit and your Garmin handheld GPS unit
4. Or if you’re like me and do a lot of back country road riding and exploring then the 705 can be nice to help you  find your way around
5. Also when racing the 705 can be nice to show you whats coming up, how tight a turn, or how much further to the top the climb, this can help you plan your attacks etc.
   or know how fast you can safely go into a unfamiliar corner at.
6. Having +ANT sport is nice as you’ll be able to use with different cycling computers and head units, but don’t let it hold you back and make you feel like you’re held back
   from collecting high quality training and race data. You’ll be able to collect exactly the same data, you’ll just be doing it slightly different and viewing perhaps different on the bike etc.

Conclusion

The good news is no matter your budget you’ll be able to collect the same data regardless of the unit you go with, the down side is that if you have to have the latest and greatest features and a new unit you’re going to pay a lot more, esp. if you want to get a Garmin 705 to work with your powertap unit.

You can get a Garmin 705 for around $400 and powertap PRO+ for $1200 with wheel so altogether expect to spend around $1600 vs.  spending about $1000 less and getting by with a
used wired unit for few hundred dollars on ebay and a cheaper handheld gps unit for around $120.

If you’re racing or doing a lot of exploring or touring around the back country the Garmin 705 can be a nice option.

Either way training with power is within most people’s budgets, so I ask to “Power or not to be”?