Tuesday, November 20, 2007

ibike update worth it

OK, so I use an ibike and have whinged a bit about some niggles. Well Velocomp has seemingly fixed all of those issues - and brought the ibike up another level.

For completeness here's a long post that covers just about everything I've ever written about the ibike and briefly describes ibike 2.0. I'll say more about ibike 2.0 soon.

The ibike and me.

OK, I'm a bike rider and a data collector. I have documented every ride I've ever ridden, and the data keeps getting better as the gadgets improve. Hey, it works for obsessive old me. Simple bike computers are great and tell you a lot. But maybe you want to measure your power output as well? This post focuses on the ibike power meter - what it does, how to set it up and the problems you may encounter - but covers a bit of bike computer history as well.

But first, the latest update!

Just a quick note about the latest ibike upgrade. It's a significant change. Firstly ibike release 1.15 upgrades the ibike unit itself to accept new features, including wireless sensors and - a big one - the use of indoor trainers. Going wireless is not only neater and easier to install but the battery lasts longer as well. Currently I get a couple of weeks out of the CR2032 battery - up to 3 - riding 7-10 hours a week. You can stretch it to 4 but the readings get dodgy. Wireless looks like a good option if you have battery problems (colder climates especially seem to reduce battery life).

Secondly the ibike 2.0 software is a massive improvement. Now you can process multiple coast downs and calibrate against a 6km ride. You can adjust - tweak, if you like - the aero and friction values to your heart's content and apply these new settings - or a bunch of different profiles if you want - after the ride. So you can forget to change profiles when you change bikes and it doesn't matter. You simply apply another profile in the software and save it.

The calibration tools are much, much better. You can also adjust barometric pressure and temperature. All in all a great upgrade for the technically minded, although the casual user may be put off at first by the greater range of options.

Power overview

OK, so you want POWER? You want to train harder, or better? Or you just want to see how many Watts it takes to ride up that hill? The ibike may be just what you want - it was what I wanted, and here I will tell you all about the tips, trips and fun I've had measuring my Wattage as I ride!!

OK, so now I'm getting into it. It's addictive. I'm a data junkie and it's making me get out on the bike and ride, just to see what it looks like when I sprint, chase a car or climb a hill. Then I want to compare sprints, compare hills... drats, I wish I had one 20 years ago! (But they didn't exist at this price, of course.)

That's the good side of the ibike - real data that makes sense. You've got to set it up right and do the coast-down test properly, as per spec, and make sure the battery is delivering the goods. But once done it's great. Of course today I punctured and swapped front wheels, but because it's just a magnetic pickup there was no sweat. I could even swap bikes as I've got a spare mount and pickup already on bike number 2. So I think ibike is still looking like a pretty good thing.

Bad news? It goes a bit screwy if you watch the Wattage display too much (it seems to jump around constantly, especially on the flat, only settling down when efforts are made, in a sprint or in a climb) - but when you download to the PC the odd figures seem to have disappeared and clarity returns. And the peak figures on the LCD don't always match the data logged. The battery seems to play a part in this, as does road surface - bumps and corners definitely throw it off.

So on to the fun.. the screenshot on the left shows power in blue and bike speed in green. You can see steady state on the left, then I accelerate to catch a slow-moving Toyota 'Landbruiser' that pulled out in front of me. You see both power and speed rise as I chase, peaking at around 865W and 45kmh or so; then as I get into the draft speed stays up (for a while, I didn't stay on as there's a nasty climb around the corner and I'm not that fit!) whilst power falls off sharply. The ibike seems to handle 'sucking wheels' pretty well. You can see that power falls away rapidly to zero until I hit the climb and have to get pedalling again. Speed falls away too and you can see me approach 300W on the lower part of the 10% climb (the bump on the right).

The next sreenshot shows a zoom-in on that power peak. You can see the effort to accelerate, the speed rising and then the power clearly falls off as I get into the draft, despite speed continuing to rise. In fact the car eventually accelerated, having suddenly realised that the rider they pulled out in front off at that T-junction was still there... and I let him go, as you see the speed dropping again. Wow.

Even better, the power breakdown (the colored box centre-screen) shows what was happening at the point where the cursor sits... all of that green in the pie chart is acceleration. The cursor itself is the black vertical line right on the power peak. So it all makes sense. When I move the cursor into the 'draft zone' the proportions all change... as you'd hope.

Bottom line? It works! What about the software?

First up, read the update above - things have improved. For teh record, here's how I found ibike 1.0 - and ibike 2.0 has installed over the top faultlessly.

Well the v1.0 software looked good enough sitting on the CD-ROM, and it seemed to install on my PC OK - and I followed the instructions - but it failed to find the USB driver first up. I followed the instructions again, went through the whole install and once again it failed to find the driver. So I went manual in control panel and found the driver had indeed installed correctly on my hard drive, it's just that the "automatic, preferred" search doesn't look there... of course. Wonder if this happens to everyone? Anyway, it really does extract and copy it to your ibike program folder, so a bit of searching will find it. It's just a manual approach is needed when 'auto' fails. Once loaded it all worked.

The software is simple. Connect, download all or some files... ooops, it crashed. And the ibike itself froze. OK, this has only happened once, but again I followed instructions, restarted the software and took the battery out of the ibike. I popped the battery back in and it fired up again and has worked flawlessly since. In fact it works better now than before. The battery started life reading 2.80V and fell to 2.70V during the 2nd ride, before recovering to 2.78V. However after refitting (and perhaps putting the cover back on a bit tighter?) it reads 2.82V pre-ride and hasn't fallen below 2.77V. The instructions say to get a new battery if it falls below 2.75V before a ride. Perhaps my first-day glitches were battery related?

Anyway, back to the software. It's good enough. It loads up the whole ride as a .CSV file and you can 'play' with power, wind speed, elevation, slope and bike speed for starters. You basically can graph it as you like it, including looking at neat breakdowns of acceleration, hill and friction readings at any point in the ride. And you can probably read and modify it in any spreadsheet, too, given that it's saved as a .CSV (but I haven't tried - yet). It's simple, but does the job for a data junkie like me. It's strange though that the ibike itself displays slightly different maximum values than that logged in the data file. That aside, overall it's what I expected. Check this out...

The setup...

Right, so it's mounted and ready to go. We have total weight, it's leveled (so it can tell if it's climbing or descending) and it seems to be sensing wind speed OK. Now we need to calculate the aerodynamic drag and the friction between road and tyre. Now we can estimate this pretty well, but the "coast" test will actually time your deceleration run - ie measure the drag induced by you and your bike on the road. So out we went, ibike and I, on our Look KG76 for test number 1.

It's harder to find a flat, smooth quarter-mile of road than you'd think. Slightly uphill is good, downhill is bad, bad, bad as it distorts the results. So naturally I chose a road that looked flat-to-uphill but actually wasn't, so I got some fantastic results. Fantastic as in no way could it be real.

Look at this: 1459W, man! Beat that!

Oh well, back to the "coast" test. In fact I kept finding roads with dips, declines, potholes, corners and really smooth fast bits. Which raised a question or 2 in my mind. Like how accurate is it when road conditions vary? And how is it calculating wind speed, let alone direction? I guess it's a straight subtraction of total airflow "in" minus forward velocity, and angle isn't relevant, but the final figures look odd... anyway, wind aside, if I calibrate on a smooth fast road presumably I'll get errors unless I only ride on that exact same smooth fast road... so are the errors small enough that it won't matter? Or when I get to new territory should I re-calibrate?

So I chose to retest a few times (OK, about 5 times) and compare. Firstly the ibike captured the whole thing, despite my many, many retests - which is good - and secondly I never again got the sort of fantastic result I got with the first coast test. Instead of 1459W I was now in the region of 600-1000W tops (I was getting tired, too, after countless sprints!!). So which 'coastdown' is correct? Hmmm.

Now if you look at the screenshot on the left (of the ibike software) you will see a few strange things. Firstly it shows maximum Watts on this same ride as 1495, yet the LCD display showed a maximum of 1459! Oddly similar but dyslexically different. On the right of the pic you will see the figures for a precise moment in my ride. Using those figures (28kmh wind speed, 8.9% slope etc) you could indeed calculate that a 72 kg rider at 47.5kmh on that slope is indeed putting out about 2100W, not the 'fantastic' figure of 1459/95. But to me, fallible old me, I could have sworn the road was (a) almost flat and (b) that there was little if any wind.

If you take me at my word, that it was a flat road with nil wind then Kreuzotter calculates it as 715W. I'm happy with that. So - assuming a multiply-by-2 glitch occurred - there's an error of more than a percent or 2, isn't there? Hence my scepticism and need to rerun this "coastdown" test until it checks out against 'expectations'. Or am I too harsh? Did the mostly flat road dip and climb suddenly for an instant, or did I pull up on the bars, lifting the front wheel a tad (I was sprinting, after all)... and maybe the wind suddenly gusted? No, I reckon it was a glitch.

So, I think I've got the "coast" test figured out and I'll keep it "as is" for now until I see questionable figures. Certainly my max power figures have come back to earth. Some doubt remains over what happens if you ride very different terrain, but it's easy enough to re-do the coast setup if on super-smooth or super-rough road. Perhaps do the coast test just before a race on a new circuit? Certainly do it if you swap bikes, but that's a test I'm going to do later, just to see what the diffence may be... I suspect it'll be neglible, though, unless my race wheels really are that much better! Did you check this out...?

Mounting ibike on the bike

No real problems here. The ibike is just like many other bike computers and comes with a bayonet-style mount that sits on your handlebars. I chose the standard size but there is also the larger vesrion if needed. Follow the instructions though, as you need to keep the ibike absolutely 'rock-solid' on the bars. I tried using old tyre as padding at first, just to make removal easier, but settled on the double sided tape provided instead. It's easy to fit, just plan where the wire goes first. It has to get down to the forks, where the magnetic pickup gets strapped on. I kept my old speedo in place and mounted the new gear on the opposite side of the bars and forks.

Mounted it looks like this...

And the mounting itself looks like this....

All in all - dead easy. Lots of twist ties to play with but no harder than a regular 'wired' bike computer. The screws that affix the ibike mount to the bars are a bit fiddly, but it's easier on a stand, or turn the bike upside down.

Once connected I powered it up and went into setup mode. All the expected stuff: time, date, total bike and rider weight, plus the 'turn 180' exercise which levels the unit. Again, good clear instructions and I used them (for once in my life). I also zeroed out the wind (I was in a garage) and took a guess as to altitude (later riding down to sea level to make that accurate - hey I was only out by 10m!).

All up - simple and quick. Hmmm, this again...

The purchase experience

OK, so I chose to buy the ibike.

The first hassle was the ibike shop on the web. They revamped it a bit since but you can't login to the shop without first clicking on a product and pretending to buy it (then the 'log-in' option finally appears). And when you try to log-in the login ID box is unclickable without 14 'tabs' to get you there. I tried 3 different browsers and 2 PCs... they all had the same trouble. Not everytime, just 9 times out of 10. Anyway, the tab-tab-tab until you get to the correct input box works. (Must admit I just logged in fine, so who knows?)

Enough whinging. I bought it online and found that the 'tracking' option didn't work for International US Post. Not to worry, I guess. 10 working days later it turned up fine, but opened by Australian Quarantine Services. Must have looked suss with 'Velocomp' written on the box... hmmm. Go figure.

The box looks like this:

Which is fine, although for around $Aussie 600/ $US450 it's a trifle underwhelming. Still, it's the technology we are buying, isn't it?

And opening it up we find the device itself, which is tiny and very light (which is good, right?):

It's showing average Watts here in this pic but it will also show maximum values.

And then I mounted it on the bike... well 2 bikes, actually. I had bought an extra mount, so I could swap from bike to bike with ease, something I saw as a killer feature of the ibike over almost all its competition.

More soon!Don't forget to check this out...

Power to the people - power meters for serious cycling

When I started this riding gig I was 16 and it was 1973. The bike was an Aussie-made Alcon, circa late 1930s and well looked after, if hand-painted. 28inch tyres, 40spoke wheels, diamond outrigger with sliding adjustment for handlebar reach and just 2 cogs on the back. On one side of the wheel was a freewheel and the other a fixie. Cool way to get started, eh? Even cooler was the mechanical odometer that clicked over incrementally with every turn of the front wheel. Ahhh, data! I started writing it down. Curiously it made me ride a bit more, just to get a scrap more data.

In the 1980s I found myself with electronic assistance in my data habit: a cycle 'computer', although all it really did was count wheel revs using a magnet and show elapsed time. It did allow me to see my current and average velocity, rather than doing the usual sums at home after the ride. And it was more accurate than some of the guesstimates I had to make. Now that sort of technology got a bit better over the last 25 years or so, but essentially remains as it was: a bunch of data based on wheel rotation over time, displayed on an LCD. (Although some of these new options are very sophisticated: check out BikeBrain for example)

Now this did make me ride for longer distances, and do more miles each week, as I could actually and accurately see when I had slacked off. And being data-obsessed I just wanted to push teh totals ever higher. Funnily enough I still had to chase down attacks, stick with the peleton over varying terrain and avoid being dropped, irrespective of what the displayed velocity was. But now I could also go 'ah, look at that average' after a hard crit.

The next leap forward in this history lesson was to the heart rate monitor. In my case it was the mid 90s and a Polar HRM. So now I could match perceived exertion against both time and distance, as well as estimate my caloric budget. It again made me ride, just to get data. Bizarre, I know. I wanted to exceed 200bpm on my local tough climb and set ever higher averages, so again I could go 'wow, that was a tough ride'.

Which brings me to my newest desire: power measurement. Up to now I've calculated it after the ride, inexactly, and longed to know how many Watts it really took to ride that hard crit. SRMs, offering measurement at the crank seemed a great option. But SRMs were (and remain) waaay too expensive, especially now I had kids to feed. The hub-based CycleOps option was still a bit rich (and what if I swapped wheels?) and Ergomo Pro was again a tad exxy and suffered (like the SRM) from being integrated into the bike. The Polar option was both expensive and tricky to set up. So I looked at the next-best options - the German HAC4 and other options from Germany and Italy, which calculated power from time, speed and altitude gain using accelerometers or barometric changes. Of course this only works on hills, but it was an option. Some of these options don't offer download, so it would be a 'write down later' sort of thing - like back to the 80s.

The HAC4 looks great options-wise but is a bit expensive compared with low-end 'real' power meters. I also looked at GPS units like Garmin's and wondered why no-one had integrated the coolest features into one unit. Maybe one day, I guess.

Anyway, I flipped a coin and went with the simplest, cheapest real-time data logging power meter I could find. The ibike. It back-calculates power by measuring the opposing forces - wind, friction and inclination - and comparing it to real speed (using a magnetic pickup). Easy to fit, easy to use. It looks the goods but does rely upon (a) your calibration accuracy and (b) unimpeded airflow. Which is to say that it misreads power if you aren't good at entering data (weight, aerodynamic and friction data, basically, although the latter is derived by the "coasting" test) or have impeded airflow (in a bunch, maybe, and certainly in a sharp corner).

I ummed and ahhed about this for weeks (whilst watching the Aussie to $US exchange rate fluctuate, too) and wondered if I really needed to spend $A580 on a gadget. I decided it was now or never and pressed the "buy" button in the ibike website. I'll tell you more later...