cycling | piggott.me.uk

piggott.me.uk

← Older posts Newer posts →

Tag Archives cycling
SO37-38, O4

Posted on February 13, 2011 by Dave Comment

Cambridge Semi Orbital 37 average moving speed: 27.45km/h.

Cambridge Semi Orbital 38 average moving speed: 28.67km/h – brought down a little by systematic error due to me having to walk around road works in Cottenham.

Cambridge Orbital 4 average moving speed: 26.34km/h which would already be a reasonable improvement on the previous best of 22.54km/h. However: that speed is as reported by My Tracks and according to a post on the user/dev group, a recent change is causing average moving speeds to be underestimated. This is consistent with the fact that my Cateye computer reports my average moving speed to be 17.0 mph (27.36km/h). Pretty pleasing for a 50 mile route!

The majority of the ride failed to record, with My Tracks reporting only a 44.35km total distance. This was not however due to My Tracks but instead due to today’s nightly build of CyanogenMod 7 for the HTC Hero (build number 20); several times when using the phone I noticed it was failing to get a GPS fix; clearly not My Tracks at fault. Luckily I was also recording the route with Route Tracer to contribute to the dataset for my dissertation and the G1 running CyanogenMod 6.1 had no trouble maintaining a GPS fix for the whole ride. I’ve exported the GPS location data from the Route Trace as a GPX file and imported it into My Tracks; which gives the above figure of 26.34km/h.

Route (using dissertation code again to render points on OpenStreetMap tiles as I’m waiting for the dust to settle after the My Maps/Fusion Tables shake up – route points are in green as one of the recent enhancements to my dissertation dataset visualisation tools is that route points are colour coded by transportation mode):

Update (26/02/11):
My Tracks once again has upload to MyMaps functionality. As I’m currently logging all rides I do with Route Tracer so I can add them to the dataset for my dissertation, I hadn’t bothered to backup the My Tracks routes when changing the configuration of my HTC Hero (whether that be removing the Market version of My Tracks to test out the new feature I developed or installing a new build of the CyanogenMod 7.0 Nightly Builds). For completeness now that MyMaps functionality has returned, I today generated GPX files from the Route Traces and imported using the My Tracks import functionality that I developed (which got added to the Market version along with the return of MyMaps functionality).

SO37 according to the imported Route Tracer data was done at an average moving speed of 27.32km/h whereas the original My Tracks record reported 27.45km/h.

Likewise for SO38: Route Tracer data – 26.95km/h, My Tracks record – 28.67km/h.

The reason for this is that Route Tracer dumps data directly from the sensors without any preprocessing whereas My Tracks filters anomalies. It seems that this has resulted in an underestimate of the stationary times. My Tracks assumes GPX data is accurate/has been filtered and so the anomalies get through (which is also why those routes have very high maximum speeds).

Here is the Google Doc with all the stats:
http://spreadsheets.google.com/ccc?
key=0At0EKwdiLZmYdFg4Mk9fdHltdWlGeWpQTHMzM3RjU3c&hl=en_GB

This entry was posted in Cycling and tagged cambridge, cycling, orbital, personal best, semi orbital, systematic error. Bookmark the permalink.
SO 35-36, CUCC T3/Potholes, Punctures and Gales

Posted on February 5, 2011 by Dave Comment
Cambridge Semi Orbital 35 average moving speed: 28.93km/h – another new best for this route, though again probably helped by the removal of the stop-start bit in town on the way out.

I hit a pothole that was hidden from view by a bus until it was too late. I think I was doing about 20mph, but may have started to slow at that point for the approaching roundabout. The hole was about a foot in diameter and three or four inches deep. My bike made a pretty nasty sound but I kept my balance. On pulling over to check the bike I realised the bars had rotated in the pop top holding them in the stem. I checked for other damage but I couldn’t see anything else. I suspect the bar slipping absorbed a huge amount of my downward momentum that would otherwise have done wheel or fork damage.

Not having an Allen key with me I came back with the bars in their now considerably rotated position (such that the drop straights actually point upwards at the back). Surprisingly it was quite comfortable; I think I might keep them like this for my next full ride and see how they are over distance.

Cambridge Semi Orbital 36 average moving speed: 27.86km/h – experienced the worst cross winds yet on this route. My Tracks now fails to upload the track to Google Maps (but Docs statistics work fine), and from what I can tell this is because the Google Maps Data API has suddenly been deprecated. Apparently the My Tracks team are working on an alternate upload mechanism. Not that it matters for SO36 as it’s the same route as the previous few rides anyway. More alarmingly, on this ride I noticed a creaking sound coming from the front forks and couldn’t remember whether I’d heard it before hitting the pothole on Monday. Fearing the worst I thought the forks might be damaged, but having done a fair amount of reading and subsequently inspecting both the fork and wheel I’ve found nothing to suggest they are damaged. The really quite conclusive evidence is that I was able to reproduce the creaking sound by scraping the front mudguard against the inside of the fork crown. So, false alarm, but I was pretty worried for a short while before inspecting it properly.

Route:

View Cambridge Semi Orbital 35 in a larger map

The final ride for this post is my 3rd CUCC training ride. Bullet points rule for this:
- Gale force winds of maximum speed 50 knots and mean speed 26.3 knots.
- Unpredictable and very gusty winds made for hazardous and not particularly enjoyable conditions – winds which are often present on the Semi Orbital route are comparatively steady and predictable and are worth having as they make up for the lack of hills – but the ones today were in no way pleasant.
- The winds were strong enough that:
  - At one point they made me pull a wheelie.
  - I sometimes pulled over, stopped and got off to wait while lorries passed.
  - Sometimes 35 mph could be done with casual effort, and other times 10 mph was a flat out job.
- There had been meant to be two groups – fast and not so fast.
- While cycling at the back of group and before we’d split off a not so fast group, unable to easily see potholes in advance, I hit one and got a pinch flat.
- Shortly after hitting the hole and replacing the punctured tube I lost the still monolithic group and due to the winds struggled to catch up.
- I at first decided to carry on in the same direction and try to repeat the CUCC T1 route.
- Partly due to struggling to recall the route and more because I really didn’t like the winds but didn’t want to just head straight back (having only done about 15 miles at this point), I decided to head back up to the Shelfords and follow the last quarter of the “Full Orbital” route I did a few times last year which I thought might be better because a) I know the route and wouldn’t be stopping and starting all the time to check the map, which isn’t particularly fun b) I knew the roads would be reasonably quiet, and suspected that they would be less affected by the winds than others – plus there are a couple of almost-qualifying-hills which would be preferable to the wind.
Wind speed and direction graphs (source: http://www.cl.cam.ac.uk/research/dtg/weather/daily-text.cgi?2011-02-05):

What I suspect was the pothole I hit (I didn’t take the picture at the time but when returning along the same road in the opposite direction):

Pleasingly I managed to turn what started out OK and then started going bad into something good. Total distance 65.50km (40.69 miles), average moving speed 25.57km/h (15.89 mph). The pothole was somewhere on the road going south from Little Shelford to Whittlesford.

My Tracks still fails to upload route maps to Google Maps due to the the Google Maps API being deprecated. Hopefully My Tracks will start using Fusion Tables soon and convenient uploads to Google Maps will be possible again, but for now here’s an image of the route produced from the Route Trace I was also creating:

Update (26/02/11):
My Tracks once again has upload to MyMaps functionality. As I’m currently logging all rides I do with Route Tracer so I can add them to the dataset for my dissertation, I hadn’t bothered to backup the My Tracks routes when changing the configuration of my HTC Hero (whether that be removing the Market version of My Tracks to test out the new feature I developed or installing a new build of the CyanogenMod 7.0 Nightly Builds). For completeness now that MyMaps functionality has returned, I today generated GPX files from the Route Traces and imported using the My Tracks import functionality that I developed (which got added to the Market version along with the return of MyMaps functionality).

SO36 according to the imported Route Tracer data was done at an average moving speed of 26.30km/h whereas the original My Tracks record reported 27.86km/h.

Likewise for CUCC T3: Route Tracer data – 23.83km/h, My Tracks record – 25.57km/h.

The reason for this is that Route Tracer dumps data directly from the sensors without any preprocessing whereas My Tracks filters anomalies. It seems that this has resulted in an underestimate of the stationary times. My Tracks assumes GPX data is accurate/has been filtered and so the anomalies get through (which is also why those routes have very high maximum speeds).

Here is the Google Doc with all the stats:
http://spreadsheets.google.com/ccc?
key=0At0EKwdiLZmYdFg4Mk9fdHltdWlGeWpQTHMzM3RjU3c&hl=en_GB
This entry was posted in Cycling and tagged cambridge, cycling, deprecation, fork, fusion tables, gales, personal best, pinch flat, pothole, puncture, route tracer, wind. Bookmark the permalink.
SO 33-34, CUCC T2

Posted on January 30, 2011 by Dave Comment

Cambridge Semi Orbital 33 average moving speed: 28.62km/h – my best ever on this route, though no doubt helped by the removal of the stop-start bit in town on the way out.

Cambridge Semi Orbital 34 average moving speed: 28.50km/h.

Route:

View Cambridge Semi Orbital 33 in a larger map

CUCC Training 2 average moving speed: 25.19km/h – a slower and shorter route than last week. Annoyingly someone ran into the back of my bike, causing the chain to be derailed and the rear gear cable outer to be pulled from the retaining slot on the chain stays. This meant releasing the cable inner from the derailleur in order to gain enough slack to put the outer back into the retaining slot on the stay and hence loosing the indexing. Suspecting that reindexing a 10-speed would take quite a while to get right, I did the second half of the ride with just a single gear at the back. It’s reindexed now and as suspected it took some time.

Route:

View Larger Map

Here is the Google Doc with all the stats:
http://spreadsheets.google.com/ccc?
key=0At0EKwdiLZmYdFg4Mk9fdHltdWlGeWpQTHMzM3RjU3c&hl=en_GB

This entry was posted in Cycling and tagged cambridge, collision, cucc, cycling, derailleur, personal best, semi orbital. Bookmark the permalink.
SO 31-32, CUCC T1

Posted on January 22, 2011 by Dave Comment

Cambridge Semi Orbital 31 average moving speed: 26.84km/h

Route:

View Cambridge Semi Orbital 31 in a larger map

Cambridge Semi Orbital 32 (variant, cuts out the not-particularly-exciting-start-that-goes-very-close-to-being-in-town-that-made-more-sense-when-I-lived-on-Huntingdon-Road) average moving speed: 27.21km/h

Route (seems to cut two and a bit kilometres off the route but also seems to save about 10 minutes of stop-start cycling in town).

View Cambridge Semi Orbital 32 (Variant) in a larger map

CUCC Training 1 average moving speed: 25.97km/h, total distance: 64.29km (greatest distance in one day since Cambridge to Oxford/Oxford to London).

Route:

View CUCC Training 1 in a larger map

Here is the Google Doc with all the stats:
http://spreadsheets.google.com/ccc?
key=0At0EKwdiLZmYdFg4Mk9fdHltdWlGeWpQTHMzM3RjU3c&hl=en_GB

This entry was posted in Cycling and tagged cambridge, cucc, cycling, semi orbital, training. Bookmark the permalink.
Return to Cambridge and yet more cycling

Posted on January 15, 2011 by Dave Comment

I completed familiarisation with the new configuration with a quick trip on the same route as previously, but going clipless on December 31st:

View North East Staffordshire 9 in a larger map

On January 3rd I intended to do something different and cycle up to Rudyard Reservoir and back. However the temperatures were subzero and despite wearing gloves and the fact I’ve never had problems in subzero temperatures before, I had to turn back halfway as the risk of frostbite became a genuine concern. I later realised why I had problems having not done before: i) with the new bike I’m going faster and so wind chill is more of an issue and ii) my clipless shoes seem to have far more ventilation than the trainers I used this time last year. On returning there was another problem: for a reason I’ve yet to find time to identify, My Tracks hadn’t recorded a single GPS point. However, as a training and test data contribution towards my ongoing Part II project, I was also recording the route using my Route Tracer application running on a G1 borrowed from the CL. Route Tracer had no such GPS problems, and so just because I can, I converted the Route Tracer GPS location trace file into a GPX file using project code and then imported it into My Tracks. The Android Market version at the time of writing exposes no GPX import feature, but I grabbed the latest source version from the Google Code repository and found that despite this it does have all the code for GPX import already written (though it seems to be picky about date timezone formatting) – I believe the code exists for use in the My Tracks test suite. I added about ten lines of code to put a GPX import button in the main activity options menu and imported my Route Tracer derived GPX trace. Presumably the reason such a button does not exist already is because either the import code is not considered mature enough, or because there is insufficient demand; hence I didn’t think it worth submitting my code (it was so basic that if it was considered worth having it would already be implemented). Once I’d dealt with the timezone problem the trace imported and I could then upload to Google Docs and Maps:

Route:

View North East Staffordshire (variant) 10 in a larger map

It wasn’t until January 10th that I was able to get out again and give the Rudyard route another go; there was more snow on the 6th and 7th, and the relative lack of daylight means that each day’s window of opportunity is relatively small. The temperatures on the 10th however were reasonable and the snow had melted fairly quickly this time around, so armed with two pairs of gloves and two pairs of socks I set out. Average moving speed was 18.76km/h – marginally higher than the previous attempt and moreover, I actually made it to Rudyard. Total distance was 30.94km/h, maximum speed 50.4km/h (31.3mph). The elevation gain was 588m – greater than even the full Cambridge orbital.

Route:

View North East Staffordshire (variant) 11 in a larger map

Finally for this post is Cambridge Semi Orbital 30 – I returned to Cambridge today for my final “normal” term. The last time I did this route was September 8th and it shows – average moving speed was 25.09km/h. That said, the wind was incredibly strong from the south, so much so that I suspect the average moving speed going up to Cottenham was more like 30km/h and then got brought down to 25km/h over the second half. In any case, work is needed!

Route:

View Cambridge Semi Orbital 30 in a larger map

Here is the Google Doc with all the stats:
http://spreadsheets.google.com/ccc?
key=0At0EKwdiLZmYdFg4Mk9fdHltdWlGeWpQTHMzM3RjU3c&hl=en_GB

This entry was posted in Cycling, Site News and tagged cambridge, clipless, cold, cottenham, cycling, familiarisation, final, frostbite, gpx, route tracer, rudyard, snow, staffordshire, wind. Bookmark the permalink.