In setting the gearing for the Cruzbike Sofrider and Freerider we analysed the solution using the Gain Ratio method developed by Sheldon Brown. The Gain Ratio is simply the distance travelled by the bike divided by the distance travelled by the pedal. If you want to calculate the Gain Ratios of a bike you are familiar with, Sheldon Brown kindly provided this online calculator. Through 2 years of testing on mountain bike gearing we have found that small chainwheel is basically never used! The Cruzbike instead needs gearing more similar to a road bike. To illustrate what the gearing is on the Cruzbike Sofrider/Freerider , lets look at the gearing of a common mountain bike and common road bike. Here's a mountain bikes gearing, calculated with Sheldon Brown's calculator:

For: 26 X 2.125 / 54-559 / MTB tire with 175 mm cranks, with 28/38/48 chainwheels and with 8-speed "Q" 12-13-14-16-18-21-24-28 cassette ... the Gain Ratios range from 1.9 to 7.5, with gear to gear spacings of between 14.3% and 20%.

Now lets check a road bike:

For 700 X 25 / 25-622 tire with 175 mm cranks, with 39/52 chainwheel and with 9-speed 12-13-14-15-17-19-21-24-27 cassette ... the Gain Ratios range from 2.8 to 8.3, with gear to gear spacings of between 7.1% and 13.3%.

Lets examine the Freerider:

For 26 X 1.5 / 38-559 / MTB tire with 155 mm cranks, with 44 chainwheel and with 8-speed 11-13-15-17-20-23-26-32 cassette ... the Gain Ratios range from 2.9 to 8.3, with gear to gear spacings of between 13.0% and 18.2%.

And now lets examine the Sofrider:

For 26 X 1.5 / 38-559 / MTB tire with 170 mm cranks, with 39/52 chainwheel and with 8-speed 11-13-15-17-20-23-26-32 cassette ... the Gain Ratios range from 2.3 to 8.8, with gear to gear spacings of between 13.0% and 18.2%.

Conclusion The Gain Ratio method of analysing bicycle gearing was developed to allow ratio comparisons to be made between bikes of different crank lengths. Shorter crank lengths are becoming more common on recumbent bicycles due to the different pedalling style and the standard gear inch method fails to account for shorter or longer cranks, so it has to be read in conjunction with the particular crank length. It also fails as an expression of gearing because it is distance measure. The comparison is made on the typical gearing found on mountain bikes and road bikes that we have studied. You can certainly find or customise typical bikes to have a wider or more narrow spacing, lower ratios or higher ratios. You can also customise the Cruzbike Sofrider/Freerider by fitting a front chainwheel that is more suited to your riding style and conditions. Use Mr Brown's cool calculator to be sure you get the gearing you need!