Working out a gradient

[Cunobelin]

The really old fashioned way.....

Get a piece of paper and lay along the road, mark contours

Now take a piece of graph paper and mark these on three horizontal axis

Draw lines vertically for the contour height

Join up the ends and you have a profile of the hill

Measure slope

[Cunobelin]

Modern way........ most Smart phones have a method of measuring angle

This is the one on the iPhone



Simply mount to bike and read angles as you climb

There are also apps that will show you graphically the vehicle position. Usually for teh 4x4 off roader

[velorog]

I have used a Sky Mounti for a number of years. When set-up correctly they do seem to give an accurate reading. You need to have a steady climbing style in the saddle. Low gears are useful as they are difficult to read once out of the saddle. The mounting brackets can be a tad fragile but providing you don't over tighten or try to fit over bar tape they will survive.

Quite good fun. It is surprising the number of so called 'killer climbs' you find that are no where as steep as claimed.

[Mick F]

It's not just the steepness, but the length of the climb combined.
Steep and short is easy, but less steep but long is hard.

Also, why is climbing a hill so difficult?
If you draw a triangle with a circa 10% slope, why is that so hard over a mile or so? It looks so easy, but it's not.

[Samuel D]

One answer is that humans have a dismal power-to-weight ratio compared to machines that have calibrated our judgement circa 2017, such as the 100-horsepower hatchbacks that pass us on climbs.

If you go slowly enough, climbing any hill need not be hard. Alternatively, if you push hard enough on the flat, the hills may seem easy by comparison. 100 years ago, a bicycle must have seemed easy compared to most alternatives then. More recently, the English Electric Lightning routinely climbed at 20,000 feet/min (about 100 m/s or the height of a Tour de France mountain pass in 15 seconds). It’s all relative.

[old_windbag]

The gradients we climb are only a few degrees and as micks drawing shows they look inconsequential. We always have the perception when facing a climb that it's like a 45 degree wall in front of us but foreshortening I feel gives us that perspective. So we see a huge steep wall of tarmac when side on it's as micks ( complex ) drawing. Our meagre power is the limit on the climbing speed as to all intents( strong headwind excepted ) air resistance isn't the main force at play, rather mg sin theta where theta is the angle of the climb. Power = force * velocity, so you can pretty well work it all out. You can also think of it being a vertical wall the same as the height of the climb and imagining carrying your weight plus the bikes up that wall in the same time.

[Mick F]

Complex drawing!

When I cycle home, I get off at the gate, and push the bike up the drive. It's about 75yds from the gate to the front door, and it's quite steep ........... 25% generally, and steeper near the top, though level-ish at the house.

Pushing Mercian is easy. Pushing Moulton is much harder though there's only 3.2Kgs in it.
Mercian weighs 10.9Kgs and Moulton 14.1kgs

Often thought of using a spring balance to find out how much force is required to push them up the drive. Mercian seems to take no effort at all in comparison.

[old_windbag]

Help is at hand at the end of a weary cycle journey up your drive

http://www.acornstairlifts.co.uk/stairlifts/outdoor-stair-lifts

[Brucey]

is your drive bumpy (or soft)? If so the small wheels may not be rolling easily, and the suspension won't be helping in the unladen condition.

Either that or you finish every journey on the Moulton too knackered to push a bike....

cheers

[Mick F]

It's tarmac, though not buttery smooth. Yes, I'm more tired riding Moulton.

Don't temp us regarding a chair lift. We've discussed it endlessly. We even considered some sort of cable car from the front door to the pub.

[thirdcrank]

Modern way........ most Smart phones have a method of measuring angle

I knew that and I have one. It had just never occurred to me to use it for this, although these days, hills are no longer for me, unfortunately. Just one more thing that they should have invented sooner.

We always have the perception when facing a climb that it's like a 45 degree wall in front of us but foreshortening I feel gives us that perspective. So we see a huge steep wall of tarmac ...

I suspect that this depends a lot on your mental approach to hills. Just as with distance riding, I worked out as a teenager that if you aren't careful, you can put yourself off before you even get off the settee. (I say "you" but of course I mean "me." ) Often, if I've ridden down a hill after riding up on another occasion, I've been surprised at the steepness. The road from Hebden Bridge to Halifax is an example. It's on my preferred route home from several rides and heading into Halifax, I always seemed to be grovelling. I put it down to being towards the end of a long ride. The first time I went the other way I realised what had been bringing me to my knees. Having thought about it, it's because I avoid looking up hills as much as possible and concentrate on the road in front. Much less chance of the little voice in the ear saying it would be stupid to ride up there.

[old_windbag]

you can put yourself off before you even get off the settee

I do that for definite. It's not so much fear of the climb as all the negative thoughts of blowing up half way and having to get off and walk. That most likely wouldn't happen as once there and in the middle of it as you just keep pushing and concentrate on the next pedal turn. But the fear of failure causes more damage to me. Just as seeing average speeds lowering etc is worrying if it continues with no reversal .

One does not want to accept time doing it's damage, but unavoidable if not slightly delayable.

[PJ520]

On the Aventure Cycling map the profile of the road south out of Yellowstone showed a steady climb but there were a couple of places where it looked like you climbed the side of a house and then dropped equally quickly. We were quite daunted when we set off but the reality wasn't that bad.
What ACA had done was use Google Earth to get the profile of the road, at the two bits that looked horrendous there were tunnels, the profiles were of the land above the tunnels.

[MikeF]

A way to reduce the gradient is to "tack" ie zigzag across the gradient. This is not easy or impossible on busy roads, which makes climbs on these roads harder.

The reduction depends on the cosine of the angle of zigzag. For a 30degree zigzag, a 1 in 10 gradient is reduced to 1 in 11.5. For a 45 degree zigzag it is reduced to 1 in 14.

[ian s]

For non rack railways the difference between sine and tangent is inconsequentially small. I have always understood all geographical gradients to be "sine", rather than tangent, because that is what a measuring wheel will measure when rolled along the hill, or a surveyors chain will measure when laid out on a hill