Tuesday, February 17, 2009

Momentum, Dog walkers - again and a neat Website!

Despite that shortage of posts to my Blog I am continuing my cycling. The recent snow and ice is behind us and the weather has turned a little warmed and the paths have turned a lot stickier. Mind you, I am taking the advice of Chris from "Chris's Bikes" - http://www.chrisbikes.co.uk/. (His placement of the apostrophe not mine by the way ;-). Most times when returning from a cycle ride I give the bike a quick hose down and brush off the mud and try to clean out the mudguards. If I don't the mudguards get so clogged up it rubs the wheels and as any cyclist will tell you it is all about building and maintaining momentum.

When you are out on a bicycle there is nothing worse than pointless slowing down. The worst culprits, in my book, are the wind and loads of unnecessary junctions on cycle paths. I do not mind hills so much as generally what goes up goes down. A hill is like an investment you put effort into going up and then you get the reward of going down hill. Not that there are many hills here in the Flatlands. I do find that when I cycle in places with some real hills it always seems harder than I remember. When it is windy I try to cycle in a direction that will put the wind at my back when returning home.

Even though I have a degree in Physics and have been cycling all my life I have never really thought about the "physics" behind the need for cycling momentum or to paraphrase the Top Gun film - "I feel the need, the need for momentum" hasn't really occurred to me. Now cycling is becoming a bit more socially acceptable even the "quality press" have positive and regular articles on cycling. So I learnt from CTC's Chris Juden - (http://www.ctc.org.uk/), via the Sunday Times - (http://www.timesonline.co.uk/tol/life_and_style/men/article5726827.ece) that riding a bike at a steady pace takes as much energy as walking at a quarter of the pace. So cycling at 12mph uses the same amount of energy per hour as walking at 3mph - which seems reasonable enough. The rub comes when you stop and start. To get moving requires the building of Kinetic energy (moving energy) which is proportional to the mass of the thing you want to get up to speed times the speed you want to reach squared ( ½mvv - I could not find how to get a superscript small 2 sorry). This means that if you stop it takes 16 times the energy to get yourself back up to the speed compared to walking (i.e. cycling at 12mph vs walking at 3mph.) but since you also have the mass of the bike then it adds up to around 20 times the energy to get up to speed. (If you cycle at 16mph then it takes 36 times as much energy) According to the article it takes around the same energy to get up to cycling speed (12mph) as it does to cycle around 100m (they changed from imperial to metric not me) whereas a pedestrian starting from stop only takes a couple of paces.

So, relatively speaking each stop makes the journey feel to be around 100m further in terms of energy expenditure. My cycle journey to the local railway station is around 12Km, a pleasant cycling distance, which as long as I do not go too fast does not lead me to getting hot and sweaty. From memory, it has around 6-8 stops, if I obey the highway code on the road - eg. stopping for traffic lights but continuing without stopping on the cycle paths. If I were to stop at all of the junctions on the cycles paths then it could mean an additional 10-12 stops. So using the above rule of thumb the extra 10-12 stops makes the journey feel as if it were 1000m-1200m longer or like adding 10% onto the journey - certainly noticeable. My journey starts along country lanes, the same route in town could easily double or treble the number of stops - no wonder some cyclists tend not to stop at traffic lights - stupid though it is - imho.

Now the weather has picked up there are more walkers and dog walkers taking advantage of the weather. Once again I came across the little old lady in her Micra with a micro dog running alongside. I had assumed that she was reluctant to step out onto the icy pavements. I was wrong, she was car walking her dog with no snow and ice around. The dog is well behaved and does not seem interested in chasing my back wheel. Elsewhere on my route there is a farmhouse with a dog that occasionally gets free and chases me. It has happened around three times now - when I am prepared it is not really an issue, I can cycle faster than it can run and although the dog runs close to my back wheel it does not seem to be a kamikaze dog. It caught me unprepared though at the weekend, my heart rate certainly picked up momentum even if I did not. I felt like complaining to the owners or the police, but of course momentum is too important to waste on slowing down and complaining. The tragedy will come when it chases after a tractor or car though.

The route I take though Wicken Fen is getting very sticky indeed. The next two pictures show the entrance to the Fen, just after leaving the road close to the car park :-(. Unfortunately they (the National Trust) seem to run quite a few vehicles around this area and have thoroughly chewed it up. I always unclip from the pedals on this part of the track, but try to maintain some momentum. The trick is to try and avoid the really thick gloupy mud, which can bring a bike to a stop. The other thing you have to do is avoid sliding into a rut left by one of the vehicles. It is a shame that it is allowed to get so bad as the rest of this Sustrans route has remained passable even on my touring bicycle.

You also have to watch out for the puddles as they can conceal some much bigger holes and rocks, generally the best thing to do is stand on the pedals and be prepared to touch down.

Here is yet another composite picture, made from three pictures, I would normally cut the picture down, but left it this time to highlight the three sections.

On my way back from the Fen whilst cycling down the lane back to civilisation a 4x4 drove past me and 40m from a T-junction stopped. Although the lane was narrow at this point I gave the car a wide berth (http://idioms.thefreedictionary.com/give+a+wide+berth) as by the time I had got there he opened the rear offside door and was leaning in. I assumed that he had a child that needed some attention, just before I went past he seemed to fling a big black Labrador out into the road. I only just managed to swerve past the poor dog. The driver did shout sorry to me, my comments were not really repeatable. Why he did it I don't know. It was not a place to stop and walk a dog, perhaps the dog was being sick, whatever the driver showed a total disregard for both the dog and other road users - me. He must have seen me because he had driven past me with a reasonable amount of space just before I went past!

One of these days I am going to cycle round recording "bad" driving/cycling/walking behaviour. Last week I was in my local shop buying a newspaper and the lady in front of me (horsey type) was talking on her mobile phone throughout her shopping transaction. After I paid and got back on my bicycle she was in her car, behind me. I cycled off only to have her roar up behind me, driving, whilst using her phone (not hands-free) and cut the corner so that I would not slow her down. This in a busy village with two schools. Is it any wonder that parents do not want their children to cycle to school and if they do to insist they use the pavement.

Just to end on a positive note. I have been trying to contact cycle shops on speccing my planned new bicycle. I have tried to contact a US company three times by email and web over the last couple of months, I have not heard anything. I emailed a company in Hunstanton (North Norfolk Coast) - Fat Birds Don't Fly, yes it is a cycle shop check it out at - http://www.fatbirds.co.uk/ I got a response the next day.

Also I have been using a new Website - Spotify http://www.spotify.com/en/ to listen to music. They have heaps of bands old and new, reasonable quality sound, all properly licensed and you can select music and listen to it (via streaming) in return you get an advert every few tracks. For me it has been a great nostalgia trip - Ten Years After, Cream, Rolling Stones. They do not seem to have Frank Zappa Live at the Fillmore though.




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