Percentage of grade - gotta love these hills!

[Jiffer]

Well, I can comment on elevation gain on mapmyride verses Garmin. Dh just did a ride yesterday that mapmyride said would be 3,500 feet of climbing and his Garmin said it was over 6,000. Almost double.

[tctrek]

To give perspective, the Tour of Ireland had a hill at the end in Cork that I think was called "St. Patrick's Hill". It was a 23% grade and the riders had to climb it 3 times in a little ride around Cork that is similar to the ride around Paris on the Champs Elysees, except that is flat!!

http://www.youtube.com/watch?v=gP1pMW1aUFU

A bunch of the pros bailed on climbing that hill because they thought the danger and chance of injury just wasn't worth it.

For me, anything over 16% grade, unless it is really, really short hill, is a nice little walk with my bike !

[Mr. Bloom]

For me, anything over 16% grade, unless it is really, really short hill, is a nice little walk with my bike !

My favorite quote at last year's Hilly Hundred...as I passed an older woman on a cruiser, she said "there's no hill that can't be walked"

Dh just did a ride yesterday that mapmyride said would be 3,500 feet of climbing and his Garmin said it was over 6,000. Almost double.

My Garmin registers "elevation change" and "climbing"...I would expect one to be double the other with the same start/finish point. Is that the possible explanation? Did he use the smoothing software as he uploaded it?

[maillotpois]

Well, I can comment on elevation gain on mapmyride verses Garmin. Dh just did a ride yesterday that mapmyride said would be 3,500 feet of climbing and his Garmin said it was over 6,000. Almost double.

My Garmin registers "elevation change" and "climbing"...I would expect one to be double the other with the same start/finish point. Is that the possible explanation? Did he use the smoothing software as he uploaded it?

My other question would be: which Garmin? Is there barometric correction? Was it run through Garmin training center or just pulled from the unit itself?

Ok, that's 3 questions.

[salsabike]

My other question would be: which Garmin? Is there barometric correction? Was it run through Garmin training center or just pulled from the unit itself?

Ok, that's 3 questions.

Right---on my Forerunner, there is no barometric correction and I get ridiculous climbing figures--have to run it through Sportstracks to get it fixed. My husband's Edge (705) DOES have that correction and usually gets it right.

[RolliePollie]

This is interesting...thanks, mudmucker, for the USGS info. I did notice that Map My Ride comes up with different results based on whether you make lots of points/clicks on the way up the hill versus just clicking at the bottom of the hill and again the top of the hill (I hope that made sense).

I do have a lot of difficulty with the hill that's supposedly 20%. My front tire is trying to come up off the ground and I'm going under 4 mph, but I don't stand up to pedal (because I can't do it...don't know why...that's another thread altogether). So based on how challenging it is and the info about USGS mapping, maybe it really is 20%!

[Jen72]

This may be a dumb question but how do you find out the percentage of grade on a hill through Map My Ride? I've been riding a few hills to work on my climbing skills and to get stronger and would like to know the grade of the hills. Is there another site I can use to find this kind of information out?

[mudmucker]

This is interesting...thanks, mudmucker, for the USGS info. I did notice that Map My Ride comes up with different results based on whether you make lots of points/clicks on the way up the hill versus just clicking at the bottom of the hill and again the top of the hill (I hope that made sense).

Actually I was just speaking of USGS data in as general terms sort of answering Mr. Silver too, since he mentioned using his county GIS data. Plus my head was in geek mode. I found and read the FAQ on the site later. And, different web mapping sites probably use different algorithms and treat the data differently. Here is a piece in the help section for mapmyride:

We report ascent and descent stats for routes when they become 'significant'. This is currently set at about 60 meters of total climb. We can't guarantee a great deal of accuracy for routes with ascents < 60m, so we don't want to confuse our users by displaying inaccurate data. For long ascents, you should see your stats appear the the right of the elevation profile.

Our ascent and descent calculation algorithms don't count every small elevation change at every point because we need to filter out 'noise' in the underlying data. Prior to our latest algorithm change, we were reporting ascents that were in many cases too high. Our new algorithm gives more reasonable results for a wider variety of routes. However, since we know that this isn't 'perfect' quite yet, we've provided the raw data in CSV format so that users such as yourself can interpret the data as you choose.

Take that with a grain of salt. I am assuming you are doing rise over run or using the percentage readout over the elevation profile info (to answer the previous post) to assess grade. So there is another level of inaccuracy based on the way mapmyride uses the elevation data.

Whatever, if your front wheel wants to come off the ground, then you are on a mighty steep hill.

[Crankin]

We don't use anything except the Garmin to determine grade. Why beat yourself up over the inconsistencies? I can determine a trend, comparing different rides, new routes, etc.
Today we did a new variation of a ride we've done several times. It has a good bit of the type of climbing I described, and is around 2,000 feet of climbing. Today's ride had some short and steep and longer and moderate climbing in the new version and the Garmin said 1800 feet of elevation.. It's the only time I have ever felt like I did more climbing than the Garmin said! Probably because it was 53 miles and I just haven't been doing much riding over 40-45 miles this year.
That said, I am the most un-techie person around and I don't have a clue how to work the Garmin. I would actually be happy just to feel like I did some very hard or a lot of climbing and my body will tell me. My DH likes the data, but even he doesn't use his Garmin that often.

[mudmucker]

I don't think anyone is beating themselves up over inconsistencies. People have questions about some things, and they want to understand it. And, some people are data geeks and they like to look at data and relate it to their surroundings.