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Updated: 1 hour 19 min ago

Re: Dissertation Birmingham Commuters

31 July 2014 - 6:16pm
Birmingham cycle commuters zip-clip razorblades under the peaks of their helmets.
Don't mess.

Re: Ten Miles a Day

31 July 2014 - 5:32pm
Hi,
Think it would be a good idea to start another thread or resurect the old one on energy expenditure

Miles a day...........its probably how you do it and that would depend on what you are aiming for / just pleasure................

Re: Ten Miles a Day

31 July 2014 - 5:26pm
Having just bought a powermeter (from a forum member, thanks!) apparently I can pretty accurately measure my calorie burn using data from that. Haven't delved into that yet as the number of calories I'm burning while riding isn't high on my list of things to know. Would be interesting, but I don't want it to tell me to eat less cake...

Dissertation Birmingham Commuters

31 July 2014 - 4:47pm
Dear CTC Members

I am an undergraduate Human Geography Student at University of Leicester.

For my dissertation I am conducting research into the cause and effect of the conflict between cyclists and motorists in the context of commuter cyclists in Birmingham. To complete this I need 15-20 volunteers who regularly cycle a particular route, such as commuting to work. This research aims to study those of all abilities, levels of experience, and distances travelled.

Research participants would need to:
-be willing to be contacted by email
-fill out a report of their commute which would answer some specific questions about their experience.
-give me the directions of the route that they take (excluding the exact locations of home and work)

My study needs to be completed by 26/09/14. I have chosen to avoid face to face contact, as email contact gives the participant greater flexibility as to when they complete the above tasks.

I will guarantee that any personal information is kept confidential (safe on a password protected computer), and the research participant will be anonymous in the write up of the work.

My email address is jp334@student.le.ac.uk

I hope to hear from some of you soon.

Yours sincerely
Jack

Re: Bonnet surfing

31 July 2014 - 4:42pm
Well at least he admits to it .

Re: Ten Miles a Day

31 July 2014 - 4:12pm
That was exactly my thought about HR.
I don't use it nowadays, and rely on my computer working it out from the GPX track.
As it happens, I have records of all my rides since I went to Garmins.

I have a favourite ride, and have done it exactly 49 times with a Garmin since Feb 2008.
30miles with 2,900ft of ascent.

Calories varied wildly with HR input. Highest 2,473 and lowest 1,634 with all levels in between. 41 rides with HR.
Since doing away with HR, the figure is much more constant. Highest 1,489 and lowest 1,428. 8 rides without HR.

Personally, I believe the "without HR" more than "with HR", as the computer works out the energy required to lift my bulk+bike up and down the hills at the speed I do it. It cannot vary very much.

Re: Bonnet surfing

31 July 2014 - 3:25pm
He's changed plea to guilty... Just have to wait to see what he gets handed down.

Re: Ten Miles a Day

31 July 2014 - 2:52pm
Hi,
We know that with a HR monitor it can be as much as 20 % out.
I was just pointing out that withOUT a HRM in the mix at all it could be far worse, comonly quoted as 40 % out and maybe even more.

I dont doubt for one minute that Ayesha does the miles and the effort.
I use mine as a comparitor from one ride to the next, and its interesting that when you have a bad time the heart rate can go up and hence the supposed energy kcals etc, goes up, but how can that be if you are the same or slower, so take care of reading kcals with minimum inputs.

Re: Ten Miles a Day

31 July 2014 - 12:41pm
There’s another great big long thread on this forum which flogs kCals to death, so I’m not going to continue that subject on this thread.
25 kCals per km + 25 kCals for every 100m climbing, has got me through Audax for nineteen years.
However, Its NOT correct.
If it was diabolically wrong, I’d be dead. If it was moderately wrong, I would either gain or lose fat %.
Reality is it is slightly wrong and I maintain fat % without feeling depleted after 200 km.

Re: Ten Miles a Day

31 July 2014 - 12:29pm
I measured my 'Baseline' calorific expenditure on a chassis dynamometer in a controlled laboratory with my exhaled breath going into O2 and CO2 analysers.
Using the Carbohydrate / Oxygen formula, I could estimate the amount of CHO used during the exercise, and my Air/Fuel Ratio. ( I didn't need to shove a UEGO sensor up my jacksee ).
It came to between 45 and 50 kCals per mile along a flat road through still air ( simulated with a speed tracking fan ).
The equipment used cost more than a commercial HR monitor with kCals ‘hotch-potch’ calculation.

Re: Help with choosing bike type and/or commute through Lond

31 July 2014 - 11:02am
aspiringcyclist wrote:One more thing, when buying a bike can you exchange a saddle for a more comfortable one for you before buying? Or do you have to pay for the bike with the existing saddle and then buy a new saddle?

Assuming you're buying new – yes you can, and if it's done at the point of sale you might get a discount . I bought through the bike to work scheme a few years ago and, on my request, the shop very kindly swapped the saddle for a Brooks, the tyres for Marathon Plus and the quick release skewers for security skewers (requiring a specific key) for the wheels. These were all at additional cost, but they gave me a discount on the tyres.

Regarding lights – there are also USB rechargeable ones that can plug into your laptop during the day. This is the one I have, although I don't use tow tow paths/unlit roads at night. If I were, I'd be inclined to invest in a more suitable front light.

http://www.rutlandcycling.com/153500/pr ... light.aspx

Vorpal wrote:If your seat post has a quick release, replace it with a bolt that requires tools, or take the saddle with you and put it in a locker, or something. Same with any detachable lights or other equipment.

+1. I always take a quick release seat post with me if I'm in central London for the day - there's generally somewhere to store it, and I can be sure of a comfortable ride home

Re: 50 mph for lorries

31 July 2014 - 9:59am
Vorpal wrote: it's only a few minutes difference in travel time.
But I am Mr Toad and must exploit the 155 mph limit of my car on all roads.

Going at 40 rather than 60 for 10 miles is a total time loss of just 5 minutes - but it *feels* like a 15 minute delay, because that's ho long the delay takes, not how long the delay is.

Traffic lights have a maximum cycle time of 120s in the UK (http://www.traffic-signal-design.com/te ... y_main.htm), although this is often reduced to 90s.
Let us assume an average of 100s and that 40% of the time they are on green.
40% of the time there is no delay on the road
60% of the time there is a delay between 60 and 0 seconds - i.e. an average of 30s.
That means the average delay from a traffic light is ~20 seconds - so passing through 3 traffic lights will delay you by ~a minute (on average)

The delay from each mile of following a vehicle at 40mph on an otherwise clear NSL road is approximately equivalent to passing *one* traffic light.

Re: Cyclist Knocked Over by Van Door

31 July 2014 - 8:34am
If your employer is good about allowing sick leave, that's good- but it would be nice for your employer to get compensation for their financial losses, just as you should for your injuries and losses, as it wasn't their fault either.
I didn't know myself that employers could have a claim against the person responsible for an accident, but now I do know, if I had a good employer I'd want them to be compensated as well as me, if that were possible. It's a rough time for a lot of employers at the moment, and rougher for the best ones who support their staff, as that makes their costs higher.

Re: 50 mph for lorries

31 July 2014 - 8:19am
IMO, overtaking safely is one of the harder things most drivers have to do. If someone doesn't have the confidence, it's safer not to overtake. In most places, the worst that likely to happen is that they go a bit slower for a few miles. Is that really all that big of a deal? Even if a queue builds up and they go for 20 miles with no place to over take, it's only a few minutes difference in travel time.

Re: 50 mph for lorries

31 July 2014 - 8:12am
Tonyf33 wrote:A lot of people are reluctant to overtake even with plenty of time/space, they just don't have the confidence to do so and are overly cautious, some people can't overtake because they get too close to the vehicle in front and can't see anything nor would be able to stop in time if the vehicle had to stop suddenly.
I've experienced many times over the years drivers whom do 35-40mph behind an HGV on a national limit carriageway but have ample space & opportunity to overtake quite leisurely but just won't.
So actually it IS these types that often create problems through not overtaking, not only do they create a hazard all of their own doing (driving too close to the vehicle in front) but hinder others who legimately and safely can make progress when wanting to overtake much slower vehicles..

Some people are just happy to be making good progress, and 40mph *is* good progress. Bring on the driverless car, the danger in the above situation is created by the reckless overtaking, not the consistent speed of the vehicle in front.

Re: Cyclist Knocked Over by Van Door

31 July 2014 - 7:43am
It's not a quick process, though sometimes the solicitors can help with that. If you are still being treated, not much can happen, anyway, except the wheels of bureaucracy grinding away. However, the solicitor probably won't take the time to call if there are no new or significant developments. If you are worried about not receiving enough information, call them and ask.

Re: 50 mph for lorries

31 July 2014 - 7:24am
So retest all drivers every 10-15 years and those who won't make progress will fail the test.

I suspect rather more gamblers who overtake without visibility will lose their licence, though.

Re: 50 mph for lorries

30 July 2014 - 11:48pm
A lot of people are reluctant to overtake even with plenty of time/space, they just don't have the confidence to do so and are overly cautious, some people can't overtake because they get too close to the vehicle in front and can't see anything nor would be able to stop in time if the vehicle had to stop suddenly.
I've experienced many times over the years drivers whom do 35-40mph behind an HGV on a national limit carriageway but have ample space & opportunity to overtake quite leisurely but just won't.
So actually it IS these types that often create problems through not overtaking, not only do they create a hazard all of their own doing (driving too close to the vehicle in front) but hinder others who legimately and safely can make progress when wanting to overtake much slower vehicles..

Re: Cyclist Knocked Over by Van Door

30 July 2014 - 11:44pm
Thanks for those points. They are both valid. Currently I am still dealing with the claim. My arm was incredibly sore for days after and I couldn't move it for a long time without discomfort. There also seems to be some longer term issues but I am having a medical examination soon to assess the severity. Nothing life changing but it causes pain where I had none previously - which was raised by the above comment with regards to long term injuries.

My employer is very good at allowing sick leave. I cant see that being an issue - although I take your point, and its an interesting point to raise to others in a similar position.


I will update in the future with my experience of C-AMS accident management who are meant to deal specifically to cyclists. So far, OK, but not enough contact. I've been called once in three weeks with little to no discussion about what I can expect to happen in the future.

Re: Ten Miles a Day

30 July 2014 - 11:11pm
Hi,

http://home.trainingpeaks.com/blog/arti ... ie-reading

"Calories Calculated with Heart Rate
Measuring energy expenditure based on heart rate has come a long way over the years along with technological improvements, and more are still popping up as we speak. There are several generations of algorithms that are derived from scientific metabolic testing, so trust that the companies aren’t just throwing numbers at you. Most of the HR based calculations are within 10-20% accurate. That’s not as close as within 5% with power, but not everyone wants to or can invest in that technology.

Most all HR devices use the basic user input metrics including gender, height, weight, and activity level combined with the heart data recorded. So the main thing with HR devices is to make sure you input as much accurate information as possible. In some devices actually inputting your tested VO2max over the device-estimated value can improve the accuracy from 20% to more like 12%. Some of the more advanced methods evolving now evaluate the time between heartbeats, called beat to beat, to estimate MET (Metabolic Equivalent), which finally is used to determine actual work expenditure. And some devices also have a “learn” function that with continued use tracks your changes in fitness and adjusts the energy algorithm. So sharing a device with a family member or friend once you may not notice different results, but frequently, then you probably would.

Calories Calculated with Time and Distance
Here is where the measure of energy expenditure really is tough to blame on the device. When there is no data reported from your body, the device is left to calculate energy expenditure based on the raw metrics including time, distance (if available), age, weight, and activity level (if device has this setting). That’s why this method can range from being 20-60% off. So, really you can’t depend on calorie estimates from a device with just these metrics. For example, a ride that may actually be 600 kcals total (500 kcals to summit a climb but a minimal 100 kcals to soft-pedal back down hill) would actually report as potentially a 960 kcal activity if the 60% inaccuracy is true. That’s substantial enough in a single workout to throw off the common -500 kcal/day deficit that often person aim for to lose 1 lb/week safely.

There are some general guidelines that exist for these calculations, but as you can see by the chart they don’t take into consideration your effort level to achieve the speed. This is a large factor because quickly you can conceptualize the difference of effort that is required to pedal at these rates; into a headwind or crosswind versus a tailwind, up a steep climb versus on the flats or descending, or even on a technical mountain bike trial versus a leisurely regional gravel path."

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