MCMBA: Highland

[surly]

Gonna try and ride this for the first time today. I am lucky enough to have more than one bike to choose from:
Full suspension 26"
or
Hard tail 29"

Thanks

Very tight and twisty. 26er.

Thanks, Took the 29'er and checked the thread after but have to agree with you. Pretty nice trail. I thought it might not suit me because I really like Pontiac style flow and speed but I enjoyed the trail a lot. It was wet enough that the roots and rocks were pretty slippery but the dirt had about perfect moisture, no mud. It was empty at 14:00 as well.

Will need to go back and ride the rest of it.

[rvd]

The trail map mentions "Vertical" for each of the loops: http://mmba.org/library/maps/highland/Highland-MMBA.pdf. Is that the maximum elevation difference (i.e., vertical distance between lowest and highest point) or the total amount of climbing?

I assume it is the former (elevation difference), as 2090ft (637m) "vertical" in 15.9mi (25.6km), seems too small to be total amount of climbing (but then, I could be wrong). If it is indeed the maximum elevation difference, does anyone know the total amount of climbing for the A-B-C-D loops?

[Critter7r]

Since the highest point in Michigan is less than 2,000 feet (and is in the U.P.), I'd guess that it means the total number of feet of actual climbing. IIRC, the map shows that the B (or maybe it's the A and B) Loop has some 800+ feet of "vertical", and there aren't any 800 foot tall hills anywhere near Highland (For something to compare it to, Alpine Valley Ski Resort is only about 350 feet high).

[ibisman]

And...its not 15.9 miles.

[rvd]

IIRC, the map shows that the B (or maybe it's the A and B) Loop has some 800+ feet of "vertical", and there aren't any 800 foot tall hills anywhere near Highland.

Oops . Thanks for pointing that out.

And...its not 15.9 miles.

It is not? Then what is it? The map gives A+B+C+D = 3.8+5.9+2.4+3.8 = 15.9 miles

[irishpitbull]

I'm only getting 14.7 miles every time I have been out there. Using cadence on my Garmin Edge 800.

[MediumRB]

And the mileage markers come out at like 16.5!

I think something like a Garmin that uses GPS rather than a wheel-rotation based system might underestimate. Remember that GPS will record a distance of 10 feet even if the trail is actually 14 feet as the snail crawls because it is going uphill at a 45 degree angle.

[c0nsumer]

I think something like a Garmin that uses GPS rather than a wheel-rotation based system might underestimate.

This is true.

Remember that GPS will record a distance of 10 feet even if the trail is actually 14 feet as the snail crawls because it is going uphill at a 45 degree angle.

This part is not quite true. Differences are more due to aliasing and noise. GPS can't generally record segments as small as you are mentioning due to insufficient signal for this.

[rvd]

Remember that GPS will record a distance of 10 feet even if the trail is actually 14 feet as the snail crawls because it is going uphill at a 45 degree angle.

Interesting; never thought about it like that. A wheel-based sensor will measure trail distance whereas GPS measures only horizontal distance. This could be one reason (in addition to the aforementioned aliasing) that GPS produces smaller numbers. Obviously the average |slope| over any trail - even highland - is pretty small, so the effect should be small too.

Differences are more due to aliasing and noise.

GPS noise increases distance; aliasing reduces it.

[MediumRB]

Remember that GPS will record a distance of 10 feet even if the trail is actually 14 feet as the snail crawls because it is going uphill at a 45 degree angle.

This part is not quite true. Differences are more due to aliasing and noise. GPS can't generally record segments as small as you are mentioning due to insufficient signal for this.

Yes, I was using a simple (short example). But the noise and broken signal issues will also mean that 25 feet of quick switchbacks might be recorded as only the 10 feet of distance as the crow flies, as the Garmin only picked up points of one's travels (in such a short distance) and missed all the extra distance between the direct route.

All I know is that it takes me more than twice as long to do Highland than Pontiac, but Pontiac is definitely more than half the distance.

[c0nsumer]

GPS noise increases distance; aliasing reduces it.

Not always true. Noise decreases accuracy which may manifest as increased or decreased distance. If you've got, say, 16' accuracy, two recorded points when moving 10' may be on top of each other, 6' past the previous one, or 26' off. It's a crapshoot. (Add to this that GPS elevation is roughly 1.5x less accurate than lat/long, so your inaccuracies in this direction are magnified.)

This is why I use a GSC-10 wheel sensor and a Edge 500.

[irishpitbull]

I think something like a Garmin that uses GPS rather than a wheel-rotation based system might underestimate.

This is true.

Remember that GPS will record a distance of 10 feet even if the trail is actually 14 feet as the snail crawls because it is going uphill at a 45 degree angle.

This part is not quite true. Differences are more due to aliasing and noise. GPS can't generally record segments as small as you are mentioning due to insufficient signal for this.

On the 800 it uses either. Depends how you set it up. Per Garmin user guide.

[c0nsumer]

On the 800 it uses wheel rotation. Per Garmin user guide.

Yep, and on the Edge 500, presuming there is a GSC-10 present. This is exactly the reason why I think it's imperative to have a GSC-10 if using a Edge 500 or 800 for logging trail rides.

[Paul Brown]

All this Garmin talk, I keep thinking I may get a trail update upon notification. Split this crap off. Or..... maybe just ride the trail and if so inclined see how long it takes you to complete it.

[irishpitbull]

All this Garmin talk, I keep thinking I may get a trail update upon notification. Split this crap off. Or..... maybe just ride the trail and if so inclined see how long it takes you to complete it.

Trail is amazing per usual. Will be out there Thursday if anyone wants to ride.