Garmin "thinks" they've figured out the 910xt pace problem and they have a suggestion...

I'm positive I've been on the bike the night before a long run and turned it on in bike mode and switched to run.  Still I experience the pace problems.  I need to get to a track to calibrate the foot pod.  I used the algo suggested on DCRainmakers site but it still seems a little off.  I'm thinking if I calibrate it at my race pace before a race, that should smooth out my real time pacing and be pretty accurate at that pace if I switch the watch to read the foot pod rather than gps.

You put your right foot in, you take your right foot out . . . .

That makes about as much sense as re-booting your computer or un-installing and then re-installing software that worked just fine yesterday. 

So...this will probably fix the issue then. 

Sorry, I disagree with that statement.  If I had the option to wait another couple of months for the bugs to be worked out or got it when I did I would still want it early.  I like the watch and the minor bugs I have encountered haven't been that major to me compared to what it has given me.  Just my opinion, YMMV

I 100% agree. I get so much out of it on everything else but the instant pace that if I had to do it over, I still would have gotten it.  On second thought, I would have gotten it EARLIER than I did.  But yeah, I wish they'd fix it haha

I don't understand why anyone expects instantaneous pace to be accurate.  You're talking about a tiny tiny unit on your wrist.  We're not talking about a bajillion dollar super accurate piece of equipment.  By the inherent nature of GPS it's going to be off by a tiny bit quite often.  That's one reason most people's GPS read 26.2 +/- 1 mile after a marathon.

I don't see why anyone would run around in ANY mode other than average lap pace...if I'm doing intervals on the track I even use that mode.  It will bounce around for a bit at the beginning of each lap but fairly quickly will settle to the closest approximation of your "instant" pace you can expect.  As long as you keep the laps short enough (under a mile) then you generally speaking will have a really really good idea of what pace you're holding.

It's like watching your power every second...or every 5-30 seconds.  If I'm watching my power every second I expect it to jump around.  If I want to really know my "instant" power I make the sure the watch is only showing me a number every 5-30 seconds.  There are some things that just aren't meant to be looked at instantaneously.....

But apparently I'm in the minority.

I always use instant pace on my 310XT. I want to know my pace at the time I look at my watch, not the average for the current lap I'm in. That doesn't tell me if I'm going too fast or too slow (or just if how I feel matches the pace I'm going) at that instant. If it's near the end of the lap, it's too late to adjust pace too.

Personally, I think they should use a 3- or 5-second weighted average for pace and be done with it. This will smooth out the small errors but be accurate enough for everyone (and more accurate than what they currently have). Maybe even give the option of 3 or 5 second weighted smoothing in the set-up.

It's all so simple when I type if from my living room...

my complaint about the instantaneous pace problems in the 910 lies in the fact that the feature works in other garmin watches (i also have the 410) . while i don't expect the instantaneous pace to be precisely accurate 100% of the time, i do expect the watch to give me a ball park figure when i choose to look at it. if i am running at a 8min/mi pace and i look down and the watch is showing me a 10:30 pace, its pretty annoying. 

my gripe against always using average lap pace is that there are times in training where i walk. the average lap pace takes my walk time into the average and doesn't display how fast i am running. i guess i could create a new lap for my run/walk intervals, but it just comes back to the fact that instantaneous pace works in their other devices. 

cgregg - 2012-05-04 7:15 PM

Meulen - 2012-05-04 11:01 AM WOW....that makes no sense whatsoever!  lol

Actually, depending on what the issue is, it makes total and perfect sense. Basically, it means that at power on, the device isn't properly initializing the device for the selected mode, but it does initialize it fine when the mode changes.... this sort of thing happens all the time with software (ummmm, not in any of the code *I* write, though ::whistles:: ). Most likely, it means that the initialization routine just isn't properly detecting (or isn't doing it consistently) the selected mode. The good news is that if this is indeed the root of the issue, they should be able to code a fix and get it tested fairly quickly.

It does make some sense as you describe above, except that I often power the device up in other sports (bike or swim morning, run at lunch) and I've never seen it fix the pace issue when I change to a different sport mode.

However, I think the instructions are to power up in the mode you need to use (i.e., run) change sports, then go back. There is some chance that this sequence is different (and fixes the problem as Garmin says) than just power up in bike and change to run, so I'm going to give it a try on Sunday to see if it works.

Xwhatever to the "It should work as well as the other Garmin devices"...

Meh, I guess I've never seen it be accurate enough on my 301 or my 310XT to be worth using.  I don't think it's a Garmin problem.  I chalk it up to a limitation of wrist-bound GPS.  IMHO if you are using the "instantaneous pace" rather than an average over ANY lap (even a quarter mile) then you are chasing an impossible dream and "reacting" instead of holding a constant effort and adjusting as necessary.

This maybe a issue of where you are in your training.

I can't pace my self well at all yet.  I need some feedback to realize I'm going too fast or too slow.  Then, often when i see it I'll realize oh yea, I am going too hard and back off.  This is especially true when there has been a weather change.

Instant isn't neeed but a current pace is helpful. 

Same with Power, if you are doing something like TrainerRoad relatively instant power is important for doing those intervals and knowing you are doing them at the intensity indicated.

I am not responding to the OP, just this post.  I don't have a 910, but my wife does....

As a software engineer, this actually makes a lot of sense to me.  Initialization problems are notorious.  As developers and testers we are almost always starting our stuff from a zero point, which is rare in the real world.  Many, many issues arise from equipment running a long time and not re-initializing properly.

I do believe they have some sort of smoothing algorithm, but I generally agree that the instant pace is not very usable, though I also am one of those who doesn't really watch instant pace.