http://citycyclingedinburgh.info/bbpress/ CityCyclingEdinburgh Forum » Topic: Cycling- 84mpg en Tue, 19 May 2026 17:51:06 +0000 http://citycyclingedinburgh.info/bbpress/topic.php?id=19304#post-296649 Thu, 29 Nov 2018 11:38:23 +0000 I were right about that saddle 296649@http://citycyclingedinburgh.info/bbpress/ <p>The carbon balance for an Iowa corn field will be interesting, including the natural gas fueled Haber-Bosch process and the agricultural diesel without which pretty much nothing. </p> http://citycyclingedinburgh.info/bbpress/topic.php?id=19304#post-296647 Thu, 29 Nov 2018 11:23:54 +0000 neddie 296647@http://citycyclingedinburgh.info/bbpress/ <p>Great points, ejstubbs.</p> <p>Now I'm dying to know the figures for all the other factors...</p> <p>CCE, go to work! </p> http://citycyclingedinburgh.info/bbpress/topic.php?id=19304#post-296641 Thu, 29 Nov 2018 10:56:12 +0000 I were right about that saddle 296641@http://citycyclingedinburgh.info/bbpress/ <p><em>IWRATS correctly calculated</em></p> <p>Take <em>that</em> CCE. &lt;<em>IWRATS does weird victory dance</em>&gt;</p> <p><em>near enough zero for an MTB</em></p> <p>Not in North Britain. Quite impassable in its native state. All paths hard won. </p> http://citycyclingedinburgh.info/bbpress/topic.php?id=19304#post-296639 Thu, 29 Nov 2018 10:50:00 +0000 ejstubbs 296639@http://citycyclingedinburgh.info/bbpress/ <p><strong>@toomanybikes</strong>: <em>Ahh you mean 500W worth of food</em></p> <p>Every time someone confuses power and energy, God kills a puppy.</p> <p>IWRATS correctly calculated the energy required to ride 20km at 20kph based on an energy consumption rate of 500W to maintain said speed. His estimates of the mechanical power output and the chemical to mechanical energy conversion efficiency of the human body seem to be pretty much on target, based on some quick Googling. So roughly 1,000mpg equivalent seems about right.</p> <p>If you wanted to delve further I suppose you could go further back down the energy chain and look at the energy efficiency of food production &amp; delivery processes vs the well-to-pump energy efficiency of the gasoline supply process. (For example, during my Googling I found a figure of 1.5% efficiency for conversion of sunlight in to chemical energy in an Iowa cornfield. Amazing what you can find online.) You could also look at the energy costs of production for the vehicles involved (bikes win over cars by a country mile), provision of infrastructure required to make those vehicles usable (ranging from, in the extreme case, near enough zero for an MTB to "quite a bit more than that" for most motor vehicles) etc etc.</p> <p>I'm sure someone, somewhere, is working on it right now... </p> http://citycyclingedinburgh.info/bbpress/topic.php?id=19304#post-296578 Wed, 28 Nov 2018 15:23:30 +0000 I were right about that saddle 296578@http://citycyclingedinburgh.info/bbpress/ <p>Drive chain good human body bad.</p> <p>IWRATS not show full working and narrative sketchy. 7/10. </p> http://citycyclingedinburgh.info/bbpress/topic.php?id=19304#post-296577 Wed, 28 Nov 2018 15:16:42 +0000 toomanybikes 296577@http://citycyclingedinburgh.info/bbpress/ <p>Ahh you mean 500W worth of food to generate 100W of useful power on the bike. </p> <p>I spent a while checking that I wasn't going crazy remembering a drive chain is ~95% efficient.. </p> http://citycyclingedinburgh.info/bbpress/topic.php?id=19304#post-296573 Wed, 28 Nov 2018 14:29:54 +0000 neddie 296573@http://citycyclingedinburgh.info/bbpress/ <p>Nice! </p> http://citycyclingedinburgh.info/bbpress/topic.php?id=19304#post-296566 Wed, 28 Nov 2018 14:15:12 +0000 I were right about that saddle 296566@http://citycyclingedinburgh.info/bbpress/ <p>Petrol has at most 34.2MJ per litre so 155MJ/gallon. </p> <p>Punters like us might be using 500W to generate 100W of useful power in the drivetrain while riding steadily at 20km/h.</p> <p>So that's 1.8MJ to go 20km. The gallon equivalent distance is 1722km or 1000 miles near enough. </p> http://citycyclingedinburgh.info/bbpress/topic.php?id=19304#post-296564 Wed, 28 Nov 2018 14:12:40 +0000 chdot 296564@http://citycyclingedinburgh.info/bbpress/ <p>Calculation widely use (some years ago) was about 1500. </p> http://citycyclingedinburgh.info/bbpress/topic.php?id=19304#post-296562 Wed, 28 Nov 2018 13:52:44 +0000 neddie 296562@http://citycyclingedinburgh.info/bbpress/ <p>Someone will be along shortly to tell us exactly how many miles a cyclist gets to the equivalent gallon of fuel...</p> <p>&lt;neddie holds breath&gt;</p> <p>I'm gonna guess around 1000 </p> http://citycyclingedinburgh.info/bbpress/topic.php?id=19304#post-296552 Wed, 28 Nov 2018 12:36:09 +0000 paddyirish 296552@http://citycyclingedinburgh.info/bbpress/ <p><a href="https://twitter.com/BlondeLilmo/status/1064995198856560640">Not bad...</a> </p>