Originally Posted by
cyccommute
Honestly, the Altus works well. It may be low end but it is easier to set up than the higher end derailers.
The Megarange is a work around. It’s meant to basically have a bailout low gear with a workable lower range. The large step is necessary because there aren’t enough gears for the smoother transition for lower gears like a 9 to 12 speed cassette gives. You could get a better gearing system but it would require some (slightly) major changes to the bike. It’s likely that your crank is riveted which means you can’t just change the chainring. If you
could change the chainring, you could replace the inner one with a 22 tooth
and replace the freewheel (it’s not a cassette) with a 14-28 freewheel which would give you a similar low gear but a better shift pattern.
This comparison shows the new system.
If you have co-op near you, you might be able to find a used mountain bike crank which would allow you to change the gearing rather cheaply.
Thanks for the info. Very useful. That chart is great too. I will have to save the link. Seems like my math is correct. Took me hours to set up a chart on Excel using the 25.9" diameter of my 26 x 1.95" tires with almost identical results. Looks like the chart is set for 26" tires.
Bingo on the riveted chainrings too.
As you can see on the chart, The biggest gap is from the two lowest gears. I have found very few situations around here with mostly short hills that require any less then the 30 gear inches the 28/24 combo provides, and the available steps to 89 gear inches (which I seldom use) using the 3 chainrings are reasonable IMO.
I was also looking at Giant's handsome Cypress 7 speed bike with it's 34 - 83 GI range, Which is enough for my needs, but with only one chainring and the big jump from 1'st to 2'nd of 34 to 48 GI on the Megarange freewheel is way too high before the steps are more reasonable, even for a recreational rider.