Compass near a magnet?

[Tim Hall]

Just find the balance point on the top tube and hang the bike from a tree branch. If the frame is steel, after a couple of hours of swinging around the bike will align itself to North and you'll see which way to ride. Probably.

And you could busy yourself looking at the moss on the tree, to get some clues there, while it does so.

 

[Dave Davenport]

Stand your smart phone upright, like a tombstone. Mark where the shadow falls. Wait awhile and mark where the shadow is now. Join the points where the shadows were and are, giving you an EW line. Easy.

Trouble with a sun compass is that there is often no sun, on the plus side it would work just as well with the basic phone I have as it would with a smart one.

 

[Tim Hall]

Trouble with a sun compass is that there is often no sun, on the plus side it would work just as well with the basic phone I have as it would with a smart one.

Probably get a better result from a bike pump anyway. A full size one, obvs, not one of those modern mini pumps.

 

[Crackle]

 

[Tim Hall]

No mention of correcting for day light saving though.

 

[Crackle]

No mention of correcting for day light saving though.

No but if you come out at a jct and need to know whether it's left or right, it'll be fine. Picking your way off Ben Nevis in a snowstorm might be more of a challenge.

 

[swansonj]

Purely by coincidence, I have recently been investigating for work the opposite extreme of "do I turn left or right": what is the greatest accuracy (or to be really precise, reproducibility) you can get out of a magnetic compass. Two colleagues and I took turns to sight on a distant object then compared results. We found that the mirror version of a standard hill-walking Silva compass (£50) gave us one degree spread, but a NATO-spec army-grade prismatic sighting compass (£500) had us agreeing to half a degree.

Sometimes I find my job requiring me to do really quite agreeable things

 

[Globalti]

The only time I ever really needed the compass was on a Polaris Mountain Marathon back in the 90s in the North Yorkshire Moors when we came to a four-way crossroads in thick forestry on a dull day and within a very short time we had become disorientated and actually had no idea which of the four roads we needed to take. A quick check on the compass soon put us right though. At other times I've used the compass to confirm route choice but that was the only time I've really needed it.

 

[Crackle]

The only time I ever really needed the compass was on a Polaris Mountain Marathon back in the 90s in the North Yorkshire Moors when we came to a four-way crossroads in thick forestry on a dull day and within a very short time we had become disorientated and actually had no idea which of the four roads we needed to take. A quick check on the compass soon put us right though. At other times I've used the compass to confirm route choice but that was the only time I've really needed it.

You've obviously never walked in a whiteout in the Cairngorms then.

 

[Globalti]

Well I have; in fact in 50 years of summer and winter mountaineering and walking I've had plenty of need to use a compass and be amazed at the accuracy that's possible in whiteout or darkness. The only time it has failed has been in the Cuillins because the rock is magnetic but there the route-finding is so complex that if you don't know the mountains well a compass probably wouldn't help much anyway.

What I should have written was: "The only time I ever needed a compass as a cyclist....."