# Edge 530 - Predicted Accuracy



## ejewels (Jul 16, 2009)

With the new MTB specific features of the new 530, it seems interesting. Anyone know what the accuracy will be on things like the grit, flow and jump metrics? I'm wondering how sensitive it will be. For example, if you're only doing smaller jumps with minimal air time (like me)... will the jump metric register? Or is it more for bike parks / bigger jumps and air?


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## Harold (Dec 23, 2003)

Your guess is as good as mine. AFAIK, this is the first mainstream GPS computer with these features.

There was some device a few years ago called PUSH that was marketed more heavily towards motorsports with a 10Hz recording interval, and it had some sort of jump sensor. I was just looking for it, and can't find anything about it, so I have a feeling the company didn't make it.


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## Lone Rager (Dec 13, 2013)

Shockwiz shows air time....or something like that.


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## Catmandoo (Dec 20, 2018)

ejewels said:


> With the new MTB specific features of the new 530, it seems interesting. Anyone know what the accuracy will be on things like the grit, flow and jump metrics? I'm wondering how sensitive it will be. For example, if you're only doing smaller jumps with minimal air time (like me)... will the jump metric register? Or is it more for bike parks / bigger jumps and air?


I'm skeptical that any of these functions are going to produce any kind of accurate data. GPS is on a good day, accurate to about 10 horizontal feet, not vertical, where accuracy is all over the place. Then factor in reduced accuracy in wooded areas and I'm not seeing how this device can produce such data. Sounds like they are pushing features to mt. bikers that are, in true Garmin style, never going to work as expected.


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## ejewels (Jul 16, 2009)

Catmandoo said:


> I'm skeptical that any of these functions are going to produce any kind of accurate data. GPS is on a good day, accurate to about 10 horizontal feet, not vertical, where accuracy is all over the place. Then factor in reduced accuracy in wooded areas and I'm not seeing how this device can produce such data. Sounds like they are pushing features to mt. bikers that are, in true Garmin style, never going to work as expected.


Haha agreed. If it has similar tech to the apple watch or similar sensors, then maybe it will be sensitive to the small stuff. I mean, it has to be somewhat sensitive/accurate if it's gauging your flow and how gritty you ride.. let alone airtime. But yes, might be a gimmick.


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## ejewels (Jul 16, 2009)

Lone Rager said:


> Shockwiz shows air time....or something like that.


Oh that thing that attaches to your shock?


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## alexbn921 (Mar 31, 2009)

I have the 530 and the jump calculations are a joke. I'm getting alot of GPS drift even in open areas.
It also thought I crashed when i braked from 30 to a stop as fast as possible.


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## ejewels (Jul 16, 2009)

alexbn921 said:


> I have the 530 and the jump calculations are a joke. I'm getting alot of GPS drift even in open areas.
> It also thought I crashed when i braked from 30 to a stop as fast as possible.


Joke as in doesn't work... isn't accurate? Wondering if its sensitive to pickup the small stuff or if you have to be Brandon Semenuk for it to work...


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## alexbn921 (Mar 31, 2009)

Take off and landing are a guess and it uses this time * MPH = distance. I jumped maybe 10 foot and it said 17. It also said I hit 40 jumps when I only hit around 20ish.


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## ejewels (Jul 16, 2009)

Ah ok. Wondering how it can tell if you're actually in the air. Like for a small gap jump... if you jump along the trajectory its not like your elevation goes much higher. Anyways, sounds like its either too sensitive or just not accurate. Thanks for the reply. Not that it matters as I only do small stuff, but was just curious.


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## Harold (Dec 23, 2003)

ejewels said:


> Joke as in doesn't work... isn't accurate? Wondering if its sensitive to pickup the small stuff or if you have to be Brandon Semenuk for it to work...





alexbn921 said:


> Take off and landing are a guess and it uses this time * MPH = distance. I jumped maybe 10 foot and it said 17. It also said I hit 40 jumps when I only hit around 20ish.





ejewels said:


> Ah ok. Wondering how it can tell if you're actually in the air. Like for a small gap jump... if you jump along the trajectory its not like your elevation goes much higher. Anyways, sounds like its either too sensitive or just not accurate. Thanks for the reply. Not that it matters as I only do small stuff, but was just curious.


Sounds like there's a lot going on with it. I could totally see it overestimating distance if it's using an overly simplistic calculation to determine distance. time*speed=distance is fine when you're talking about straight line travel, but jumps are definitely not straight lines. Very short distances at high speeds might be approaching straight lines, but jumping is effectively projectile motion and is described by more complex formulas.

To calculate that, you need to know the departure angle of the jump, and there's no way your the Edge 530 is able to do that. Even with an accelerometer, determining the departure or landing of a jump can still be guesswork (and I can't even tell how Garmin calculates jumps - none of the reviews I've found say anything about the "how"). Especially the takeoff point. The aforementioned Shockwiz is better able to determine these points, but still isn't perfect.

If the Edge 530 IS using an accelerometer, I could see it being so sensitive that it is able to tell any time one of your wheels leaves the ground, so it's throwing in a whole lot of little things like manuals and wheel lifts, too, and maybe even confusing some high speed rollers with jumps. Garmin's support website says there are sensors embedded into the device (though they don't say what kind) that are used for incident detection but that the head unit will also use data from other sensors, as well (if present) to determine if an incident occurred. It's all rather vague, but I wonder if Garmin is using those incident detection sensors for the jump metrics.

I've definitely heard that Garmin's incident detection doesn't work that well, either. It gets triggered very easily if you're riding a bike with no suspension, like a road bike or a rigid mtb, on an especially rough surface. Say you ride off a curb or hit a pothole. And mtb's ridden aggressively in really nasty terrain landing drops and whatnot can trigger it.

IMO, a better location for a crash detector is in the helmet. Like how the old ICEdot system worked. You could stick a little sensor to your helmet and pair it with your phone. But that service didn't last. I know I never bothered with it because I ride so much in places with no cell reception. The spots I get reception are up on ridgetops, and that's not where I'm gonna crash. I'm gonna crash down in the valley somewhere, where I probably won't have reception, and no automatic incident detection system is going to work to get an emergency alert out to anyone.

I treat Live Tracking through a phone the same way. IMO, if you want legit live tracking that works independently of cell reception, get a SPOT or InReach.


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## ejewels (Jul 16, 2009)

Yeah, hopefully some more mtb - specific reviews will come out soon where they actually test the jumping... with all sizes, trajectories, etc.


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## Lone Rager (Dec 13, 2013)

When you're not touching the ground, the CG of you and your bike has essentially zero acceleration, i.e. freefall. That's easy to detect. If you do some tricks in the air, the bike (and attached Garmin) will experience small accelerations as you move the bike with respect to you. These will tend to sum to zero while in the air. That's the physics. I have no idea what the the Garmin algorithm does.


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## ejewels (Jul 16, 2009)

This guy did a review:





If you look at the jump data later in the video and the footage of him jumping in the beginning, it seems a bit inaccurate. No way those are 30 foot jumps. Maybe the last one is close. Hard to tell though as he doesn't show all of his testing sessions. But 30 foot jumps for a guy who isn't really a "jumper" seems big. But who knows, IDK the guy and he seems to be a good rider. The review is great... he seems to like it.


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## Le Duke (Mar 23, 2009)

As others have alluded, vertical precision is the least accurate component of GPS coordinates. 

The entire concept seems flawed, to me. I’m guessing Garmin realizes that most people have no idea how GPS works and thought this would be an easy selling point. 


Sent from my iPhone using Tapatalk


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## alexbn921 (Mar 31, 2009)

I jumped 10 times on the road ride back from the trails and never left the ground once.


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## ejewels (Jul 16, 2009)

alexbn921 said:


> I jumped 10 times on the road ride back from the trails and never left the ground once.


haha oh man...


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## Harold (Dec 23, 2003)

alexbn921 said:


> I jumped 10 times on the road ride back from the trails and never left the ground once.


Any idea what the computer was picking up? Curbs? Cracks/seams in the pavement? Changes between surfaces?

Are you sure you weren't bunny hopping kids?


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## alexbn921 (Mar 31, 2009)

Harold said:


> Any idea what the computer was picking up? Curbs? Cracks/seams in the pavement? Changes between surfaces?
> 
> Are you sure you weren't bunny hopping kids?


Maybe when I put my seat down or up but most are just random. One jump at the bottom of the hill said 17 feet. LOL. Shock wiz jump count and time is much better.


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## Harold (Dec 23, 2003)

alexbn921 said:


> Maybe when I put my seat down or up but most are just random. One jump at the bottom of the hill said 17 feet. LOL. Shock wiz jump count and time is much better.


Awesome.

Yeah, I hear ya on the Shockwiz...except that it gets confused by the MRP Ramp Control cartridge.

I've thought about buying a Shockwiz to help with bike setup between all my wife's and my bikes, though.


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## alexbn921 (Mar 31, 2009)

Update. Did a ride today and had GPS on the screen as it seemed to drift all over and it never changed from 9 feet, but showed me over a mile off course. It would snap back and then drift off into never never land. not happy with the 530.


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