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Re: Gearing efficiency

cotterpin
12 July, 2011 12:38PM
This is a "how long is a piece of string" question, because the transmission efficiency of a chain decreases as the size of the rear sprocket is reduced. It is also variable according to the quality and age of the chain itself. A new chain running on new cogs (19 teeth, six speed derailleur) can achieve 98.4% when powered at 400 watts, whilst a single speed achieves 99.0% and a three speed hub transmission in mid range (direct) 97.9%. (Fitchel & Sachs 1987).
Shaft drives reduce the efficiency of a three speed hub gear by about 9%.
Have a look at Bicycling Science (D.G.Wilson) for an overall view. He quotes a total of 39 references ranging from work done in the 1890's up to about 2000.
Subject Author Posted

Gearing efficiency

Murray R Langton 11 July, 2011 11:31AM

Re: Gearing efficiency

DocB 11 July, 2011 12:11PM

Re: Gearing efficiency

cotterpin 12 July, 2011 12:38PM

Re: Gearing efficiency

Murray R Langton 12 July, 2011 04:47PM

Re: Gearing efficiency

cotterpin 12 July, 2011 07:39PM

Re: Gearing efficiency

Murray R Langton 13 July, 2011 02:03PM



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