There is a rather steep and long hill on my commute that I cannot climb with my current setup. I avoid the problem by driving this part of the commute (it is the beginning of my morning commute and the end of my evening commute). But, I would like to provide a lower gear ratio on my bike so that I can start biking directly from home.

So, here’s what I’m looking at. I ride a stock Iron Horse XT2100 hybrid (1997, I think, but I’m not positive). I have an 11-28t 7 speed cassette in back using a Shimano RD-MC16 rear derailleur. I had thought about replacing the cassette with an 11-32 (preferable) or 11-34, but I cannot find any cassettes in that range (Shimano used to make one but doesn’t any more; SRAM makes a 12-32, but I don't want to loose the 11t I currently have and IRD makes an 11-32, but no one seems to stock it, including IRD). In addition, this chart indicates that the largest number of teeth I can have in back with the RD-MC16 is 30 (http://www.bikepro.com/products/shim...r05_table.html). I also have a 42-34-24 crankset in front (Shimano FC-MC16, which indicates that it takes an IG chain only).

So, my questions are as follows:

• If 30t is really the maximum on my current derailleur, can I purchase another cassette (say an HG-50 13-30t) and replace the 28t on my current cassette with the 30t on the new cassette? Sheldon Brown seems to indicate that I can: http://sheldonbrown.com/k7.html (see building custom cassettes). That might be enough to help me get up the hill, although I would prefer 32t.

• If I want to exceed 30t on my current cassette, will I need to replace the rear derailleur? If so, recommendations?

• If I exceed 30t in my current derailleur (or if I replace the derailleur) can I purchase another cassette (say an SRAM PG730 12-32t) and replace the 24 and 28t on my current cassette with the 26 and 32t from the new cassette?

• Finally, if I make a new cassette by replacing one or two of the cogs with one or two new cogs, should I also replace the chain? The current crankset specifically says that I should use an IG chain. Will an SRAM PC-870, or a Shimnao HG 50 or HG 70 chain work with this crankset and cassette combo?

And yes, it is a cassette, not a freewheel. The rear hub says Shimano FH-MC12 on the outside. My one confusion on the rear hub is that the bikepedia page (http://www.bikepedia.com/QuickBike/B...8146&Type=bike) says that the rear hub has a “silent clutch” but I don’t think the FH-MC12 is a silent clutch. But I have learned enough from reading through Sheldon Brown to realize that if I do have a silent clutch I may have more difficulty working on the cassette.

I had thought about replacing my bike with a new one that has a wider ranger of gears, but I'm not really happy with the bikes in the $700-1100 range that I have been able to test ride and I am pretty comfortable on my current bike (even though it is quite heavy). So, I thought I would rather work with my current bike if the cost is not too high and save up to buy a much higher quality bike in the future.