Saturday, March 04, 2006

Day 4: Garmin Forerunner 205 Solo Run Over Forested Trail

Good news today. First, hats off to Garmin's customer support for sending me the replacement Garmin Forerunner 205. They ended up sending it Next Day Air for delivery on Saturday and it arrived this morning. Service doesn't get better than that. The unit is all charged up and ready to use for my run tomorrow.

Second, if you run often on tree-covered/forested routes and/or through challenging GPS reception conditions, and have qualms whether the 205's GPS accuracy is improved enough over the Garmin Forerunner 201 to make it worth the extra money, well, this post might help you make up your mind. Disclaimer: your mileage may vary.

There was a lull in the rain that has afflicted the San Francisco Bay Area this week and I woke up to a crisp, sunny morning with temps in the upper 30s and some lingering fog. I only used my broken-buttoned 205 for my run and took a chance on some dirt trails nearby that usually caused my 201 tons of GPS reception problems.

I ran an out-and-back route with the first 2.2 miles over local streets and a paved walking trail. This put me at the trailhead staging area/parking lot. The trail is part of the East Bay Municipal Utility District (EBMUD) and goes along the East side of the Upper San Leandro Reservoir. Due to the recent rain, the trail was very muddy in spots, but luckily I was able to navigate them without losing a shoe.

The photo above is of the 1.1 mile segment that goes from the staging area through a wooded section to a dirt fire road that comes to a cattle gate. After the gate the trail starts to climb in the the hills and woods. On my 201, I would usually lose the GPS signal in both the wooded section, and as the trail climbed into woods to the 1.1 mark.

The photo above and below were both generated by SportTracks and Google Earth. The yellow line is the path generated by the 205 and the red line is from a run last week over the same trail in similar conditions (clear and sunny) using the 201. While the 205 stayed pretty close to the trail in the above segment there was a lot of wandering by the 201.

The photo above is of the next section of the trail that I've never been able to accurately measure due to my 201 always losing the GPS signal. This part of the fire trail rolls up and down, following the contours of the steep, forested hills as they rise above the reservoir.

There are parts that are heavily shaded and I would usually just run for a prescribed amount of time before turning around and heading back. Most times the 201 measured the out segment at least 15-20% shorter than the return so I would end up guesstimating the distance by dividing the total time by my perceived pace (i.e. 10 minutes at around 8:30 min/mile equals approximately 1.15 miles.

The 205 did a very good job tracking along the actual trail. There was some wandering but it was nowhere near the amount the 201 did on this section from last week's run. Plus, I never had a weak GPS signal warning on the 205 today and the GPS accuracy data field always stayed within 20-30 feet.

I was duly impressed with the 205 today. The overall distance of the run was 9.68 miles on the unit. SportTracks calculated the distance by crunching the GPS waypoints at 9.67 while MotionBased used their algorithmn to clock it at 9.76 miles.

The 205 really nailed the splits of each segment. Going out it recorded 2.23 miles to the trailhead, 1.09 miles to the start of the rolling/winding/shady section of the trail and then 1.51 miles to my turnaround point. The way back it recorded me at 1.5, 1.11 and 2.23 respectively. Very consistent. Here are the run details at MotionBased if you're interested.

I like buying the newest gadgets so I could easily justify the 205 purchase, because of its better form factor (e.g. shape, more comfortable strap, lap and start/stop buttons, etc). Plus it has more advanced features than the 201. However, until today I wasn't sure if its increased accuracy was really worth the extra money.

On my other runs the accuracy differences between the 205 and 201 were minor. Only until the waypoints were mapped by SportTracks or MotionBased could you really notice a difference. However today's run definitely highlighted the 205's improved GPS accuracy and reception.

So like I say for other mobile devices, it really comes down to the individual usage model. If you're not an anal data geek, don't want to spend two fitty and/or run on wide open routes with great GPS reception then the 201 should be fine.

However, if you regularly run routes that go under heavy tree coverage and/or challenging GPS reception conditions then the 205 or Forerunner 305 might be your better bet, especially if you want the most accurate measure of how far you ran.

Again, your mileage may vary and this was only one run under cover....

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