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  1. #1
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    Decent GPS with wheel speed sensor?

    I'm currently running a Cateye Enduro on my mountain bike, along with a Garmin Edge 200 GPS for ride logging.

    I've measured out the wheel circumference several times to make sure the Cateye is as accurate as possible. Every ride, the Garmin is substantially off on distance. It averages about a mile short on a 12 mile ride. I know this is from signal loss in the heavily treed areas I ride, but it drives me nuts to know that it's that inaccurate.

    Are there any decent, not outrageously expensive, GPS units that have a wheel sensor like the Cateye (or any bike computer) does that will keep the distance and speed accurate when the GPS signal is spotty?

    As it is now, even when I have a GPS signal, it reads very low when climbing at low speed. I'll be going up a fireroad at 4-5 mph, and the GPS will consistently show 2-3mph. If I was moving that slow, I'd barely be able to maintain steerage. I've noticed that my Edge 200 is consistently showing slower speed than the Cateye until I get up to around 18mph, then it shows faster.

    I'm just looking for accuracy if possible. When it's that far off, I can't really trust the distance or speed logged on my rides.

    Any suggestions?

  2. #2
    Fat-tired Roadie
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    Edge 500?

    A couple of the ForeRunners are also compatible with bike sensors. Polar makes a couple cycling computers; I think some of those do both. Some of the smart phone apps are getting bigger and bigger constellations of accessories. I think you could build up a system with some of the Wahoo Fitness accessories if you use an iPhone.

    Or you could just not worry about it. I know that's a little bit of an ass thing to say, but elapsed distance isn't a terribly useful way to log anything else, and it's annoying to use to navigate if you also have GPS data about your trails or just ride them by knowing them anyway.
    "Don't buy upgrades; ride up grades." -Eddy Merckx

  3. #3
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    Decent GPS with wheel speed sensor?

    The edge 200 is no good for twisty trails. I can almost guarantee, however, that it is not inaccurate due to signal loss unless you are seeing this happen frequently. The sampling algorithm is going to be the primary culprit.

    Garmin is the old standby but just about every bike computer mfr is introducing models with gps nowadays. A little late to the party, I say, because Garmin has been honing their products for better than a decade.

  4. #4
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    So what is good for tight, twisty, very rough single track? What will track my ride while keeping accurate with a wheel sensor?

  5. #5
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    Decent GPS with wheel speed sensor?

    Anything with 1sec sampling intervals

  6. #6
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    So which ones have 1 second or configurable sampling intervals? Ideally I'd like 1second intervals with a wheel sensor. Cheapest one I can find is the Edge 500 at $350 or so with the sensor.

  7. #7
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    sampling intervals are often not spoken about in product lit. Models I KNOW lack 1sec sampling include the Edge 200 (also no speed/cad sensor). I think all of the other Forerunners and Edges will do it. So will all of the handhelds. Any handheld with ANT+ capability will receive a speed/cad sensor. Some of the Forerunners will. I got a refurb FR310XT today that cost me $170 that does 1sec sampling (even without the sensor) but it is also compatible with the sensor. I also got a 1/4 turn adapter for it so I can snap it off of the watchband and snap it onto my stem.

  8. #8
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    While the Ant+ Garmin handheld units will pair with the speed/cadence sensor, they only read & record the cadence.

    Obviously a marketing decison on Garmin's part. No technical reason why the handhelds couldn't do wheel speed. But Garmin wouldn't want the less expensive handheld units to canabolize their higher priced bike specific market.

    I got the Oregon 450 for $199 for the maps and flexability. The specs said it paired with the s/c sensor. I found out is didn't do wheel speed a couple of days after I plunked down my money.

    A couple of months later, I wanted an easier to access readout for the heart rate (easier than pulling the GPS out of my pocket while sking). I got an FR60 watch for $69 (no GPS - just Ant+). It has the fitness features like heart rate zones, High/Low HR allerts, time allerts, etc. It also does wheel speed and cadence. The two units combined give me the functionality of an 800 for about half the price.

    One thing to remember on the 1 sec record is the 10,000 point limit. That equates to about 2:45 ride time. I understand that after it reaches that limit, it spews the oldest 2,000 points into an archive file. It's all still there, just split into chunks.

    By playing with the record frequency you can manage how long an activity fits in that 10,000 point limit. I set my 450 to 2 secs to let me record 5.5 hr cross country ski trips. Every 4 seconds gives you 11 hrs.

  9. #9
    Fat-tired Roadie
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    I have the Forerunner 610. Data recording can be either "smart," which lets the device choose the frequency, usually every 2-3 seconds, or it can be "every second." It's smaller than the two triathlon watches and supports all bike functions except a power meter.

    I figure if I can afford a power meter in future and want one enough to pay for it, it won't kill me to buy an Edge or the 910. For now, I really like this watch. Just using the old rubber adapter to put it on my road bike, I wear it on my wrist on the MTB or to go for a run, and I'm not supposed to even be able to see it on a track day.
    "Don't buy upgrades; ride up grades." -Eddy Merckx

  10. #10
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    I ended up getting an Edge 510. Setting it up now. First ride with it Sunday. We'll see how accurate it is compared to my wired wheel sensor (CatEye Enduro 8), and how much Strava chops off the ride when I'm done.

  11. #11
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    I have an older edge 705, set for 1s intervals, and have recorded gigantic tracks ... think 12 hr events.

    MapSource completely blew up on the track, although TopoFusion was fine with it.

    Of course, now I have a much faster PC and that helps too.

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