http://citycyclingedinburgh.info/bbpress/ CityCyclingEdinburgh Forum » Topic: Tyre/ Tramline Incidents en Mon, 18 May 2026 09:45:33 +0000 http://citycyclingedinburgh.info/bbpress/topic.php?id=15780#post-205117 Sat, 21 Nov 2015 17:11:18 +0000 Tulyar 205117@http://citycyclingedinburgh.info/bbpress/ <p>Daughter Scoosh needs to get her survey listing a bit tighter. No trams in Newcastle (T&amp;W Metro) or London (DLR) - absolutely no possibility that you'd be riding anywhere near rails on DLR, and if on Metro you'd probably be trespassing and riding on ballast.</p> <p>Interesting that they have focussed on trams , as there are probably as many crashes on level crossings, and other street ironwork (manhole frames protruding more then the 3mm limit above the abutting road surface - yes - go check!), although obviously the profiles and plan areas are different.</p> <p>I suggest that the friction issue cannot be considered in isolation. I've identified 5 ways in which interactions with grooved rail embedded in a road surface can cause loss of control for any wheeled vehicle, some are also speed dependent, as I tested (slightly unintentionally) on a level crossing the other month. Travelling more slowly on the regular track my front wheel was deflected and dropped into the groove. I went back and crossed at a more normal speed - no problems. </p> <p>I gather that there are some locations in Edinburgh where the crossing angle might suggest a rash of falls, but the way that the cyclists cross the rails avoids this (fast*, and without turning or braking) and the road surface surrounding the rails is smooth and high friction </p> <p>* perhaps counter intuitive but with the greater rotational inertia in the wheel acting against forces trying to turn it or slide sideways (in some circumstances*) make a fast and straight crossing of rails inherently safer. </p> <p>The potential for a massive variation in the available contact patch (1 point, 2 point, being unloaded by profile of surface, in contact with/without high friction surface under part of the contact patch (eg rail head = 50mm contact patch = 110-120mm x 10-20mm - 'ellipse') </p> http://citycyclingedinburgh.info/bbpress/topic.php?id=15780#post-205094 Fri, 20 Nov 2015 19:37:32 +0000 gembo 205094@http://citycyclingedinburgh.info/bbpress/ <p>I haven't due to only going over them close to 90 degrees but I am having quite a time with the cobbles of east Claremont street. The setts are moving apart and in the rain it is very bad for sliding </p> http://citycyclingedinburgh.info/bbpress/topic.php?id=15780#post-205079 Fri, 20 Nov 2015 15:53:41 +0000 Scoosh 205079@http://citycyclingedinburgh.info/bbpress/ <p>Have you ever slipped/ come off/ had an incident with your bike and tramlines ? :ohmy:</p> <p>Daughter Scoosh is involved in a research project and would be grateful if you could complete <a href="https://leeds.onlinesurveys.ac.uk/tyretramline-incident-reports">a survey here</a>. It'll take about 10 mins and is specifically interested in the type of tyres being used - so they'd like you to remember details like make of tyre, size, pressure etc ! ^_^</p> <p>Incidentally, Tribology is all about friction, wear, and lubrication. The science behind how things move and slide over each other.</p> <p>Thank you - and feel free to invite anyone you know who may have had a similar incident, even if not on CCE - nor even in Edinburgh. </p>