Bicycle Mechanics: Questions about Bicycle Rear Cassettes

[kap]

The advantages and disadvantages between the rear Cogs 9-speed, 11-28 teeth and the 9-speed, 11-30 on a 2008 Giant FCR 1 Road/Sport? TiA

[Buzz]

you'll be able to climb a slightly steeper hill w/ the 30 than the 28...


though if you never climb that slightly steeper hill, you'll be lugging around a few extra grams of weight w/ the 30...


which will burn more calories and make you fitter, and/or tire you out ever so slightly sooner.

frankly, not sure which are the advantages or disadvantages; though wish I could I could ride again (the memories from 15 years ago haven't faded...)

[cyclemax]

For a Road/Sport bike, and depending on the front gearing and your riding level, unless your climbing steep grades your shouldn't need a 30 and probably won't use the 28 much. I believe the Giant has a 34/50 Crankset. A 34/28 should handle most road situations.

[btfc]

To fully answer this question you need to look at a gearing chart. The answer depends on the size of your front chainrings, and the complete range of the rear cassette. More generally, the 30 tooth sprocket will be helpful if you live in a more hilly area.


http://www.geocities.com/SiliconValley/P...Gears.html

http://home.i1.net/~dwolfe/gerz/howto1.html

http://www.panix.com/~jbarrm/cycal/cycal.30f.html

Check into half-step gearing.

[kap]

I live in an hilly area. It's only 1/2 mile from the flat spot of the main drag to our place but it is quite steep. How steep? on a more expensive carbon fiber bike it would be a breeze. Now how do I determine its steepness?

btfc, thanks for those links. Great info there.

[Black]

Make sure you don't need to switch to a long throw derailleur for those extra teeth . . . I think I've got a 32 on my road bike.

[kap]

cassette SRAM PG-950 11-28T, 9 speed
chain Shimano HG-73
cranks Shimano FC-4550-S, Compact, 34/50