Rod, There is some of a sound explanation for this! It turns out that in addition to the calculation of appropriate ratios to maintain a certain cadence, there is also prefered rings and cogs for efficiency of power transfer. The larger rings and cogs are more efficient - and the explanation has to do with the mechanical advantage (leverage) of the larger cogs and chainrings (due to the longer distance from the pivot (the axle)). Bruce Timmermans once had a graph showing the efficiency of the power transfer through different ring/cog combinations. I never saw the graph, but know he had one - I believe more of the advantage can be accounted to the larger cog rather than the large chainring (makes sense). There may also be a teeny advantage with the large chainring in fewer rotations of the little wheels at the rear derailer (I forget what they are called - I once knew, but my brain leaks these tidbits sometimes).
The efficiency gain is small however - and the more important factor will be to pick a ratio that maintains an appropriate cadence - but if you have two chainring/cog combinations to choose for the required ratio (as there is an overlap of ratios between the two/three chainrings), then choose the larger ring. Michael > Date: Wed, 03 Oct 2001 19:57:28 -0400 > From: Rod Plunkett <[EMAIL PROTECTED]> > Subject: Why is Large Chain Ring sometimes easier? > > > I'm sure this question has been asked before, but I > couldn't > find the answer. I am finding I prefer using my > large chain > ring, even on some slopes below a certain grade. Why > is > this? Is it because I get better power transfer, > instead of > losing some as a result of the flexibility of the > chain? > This does not make perfect sense because I still > have to > transfer power via the chain. Anyone have an > explanation? > > -Rod P _______________________________________________________ Do You Yahoo!? Get your free @yahoo.ca address at http://mail.yahoo.ca ------ To unsubscribe, send a blank message to [EMAIL PROTECTED] Club Office: [EMAIL PROTECTED], (613) 230-1064 Web/mailing list: [EMAIL PROTECTED] http://www.cyberus.ca/~obcweb Newsletter: [EMAIL PROTECTED] http://www.cyberus.ca/~obcweb/Newsletter ==^================================================================ EASY UNSUBSCRIBE click here: http://topica.com/u/?aVxiDo.a2i8p1 Or send an email To: [EMAIL PROTECTED] This email was sent to: [email protected] T O P I C A -- Register now to manage your mail! http://www.topica.com/partner/tag02/register ==^================================================================
