I bought a 2009 Fuji Roubaix last year (which I love). It came with a 9 speed Sunrace cassette 11-25. But I need a lower gear and am willing to give up a higher gear as I don't ride as often as I like, am older than I would like to be and live in a hilly area. Two Questions: 1. Would I get noticable lower gear with a 12-32 or 12-32 spread; and 2. What are good cassette choices - Shimano, Shram, anyone else?

Thanks.

A 32 would definitely be a lower gear, by a lot. What do you have in the front, what model shifters/derailleur? I buy Shimano for Shimano and Campy for Campy, and have never tried anything else. SRAM is supposed to be good but I've never tried it.

The Shimano Tiagra rear derailleur on that bike will only work with a cassette that has a maximum cog size of 27T. (Although a 28T can be made to work OK.)
You've already got a compact crank on there, so maybe you should look into installing a triple crankset instead.

Again, you have no idea if that is true. Max cog size is not the typical wisdom that gets passed around here. It can be lower or higher than the stated max cog size for that derailleur depending on the exact frame and hanger.

If your bike is already shimano equipped keep the cassette shimano. And if you're going to go to 12-32 you'll very likely need a new derailleur as well in addition to chain.

This may or may not be true, but your obfuscating the obvious issue here isn't helping anyone.

It *is* true. Go read barnetts for an explanation. Specifically chapter 32 of barnetts.

https://www.bbinstitute.com/dl/dx_demo_chapter_32.pdf

Search the term "max cog size". The only thing that is not helping is your ignorance on the issue and passing fradulent information.

It's true that a Tiagra might not work with a 32T cassette. 32T is the 50/50 chance for many derailleurs from Shimano that state 27T as the maximum cog. Same holds true with the Ultegra RD. It might work - it might not. If it won't handle a 32T Tiagra, it's time to look for a true mountain-bike RD, such as an XT:

https://www.amazon.com/Shimano-M772-S.../dp/B000YBCNAA

I'd try the Tiagra first, but it's right on the edge where various parameters of the frame, chain-line, etc. - come into play making it iffy at best.

Since your reference refers to this:
https://techdocs.shimano.com/media/te...9830607047.pdf
maybe you should pull your head out and give it a read, Einstein.

Again, demonstrating your ignorance.

Yes, that PDF says that max cog size is 27t. Big whoop. If you've actually read that pdf i've linked you'd realize why that specification can differ in either direction. Go educate yourself and stop posting garbage that clearly tells us you have no idea what the **** you're talking about. I'm really getting tired of this bull**** on this forum.

"Einstein".

I've got a Shimano 105 RD that says max cog size is 27t, and I have been runnng a (IRD) cassette with a 30t cog for the last 5000 miles without any issues at all. As previously stated, there are several considerations, such as the geometry of your frame/hanger, and the size of the large/small front rings that you intend to run.

Also, a SRAM cassette will work fine with a Shumano rd. I interchange Shimano, SRAM and IRD cassettes with the 105 RD without any issues.

If you read my original response properly, I think you'll see that I mention that a cassette with 28 teeth can be made to work in most cases. Now I realize this is a stretch for you, but people with a moderate grasp of the English language can usually construe from that that the rule isn't absolutely firm. And as long as the derailleur hanger is within the range Shimano specifies - which, believe it or not, pretty much everyone in the industry does (golly gee, I wonder why) - then you can pretty much always assume that at least a 27T big cog will work. All this taking the manufacturer's word for it and not considering my own experience that you obviously have no respect for. At least I'm not alone.
You've made it a little ritual of yours to come on here and spout your emotional diarrhea at anyone who dares have an opinion that doesn't quite mesh with yours in the right way. You're not helpful, you're just a prick, and the bull**** I'm tired of on this forum is yours. Serious advice: See a shrink, get laid, and/or ride more. You've got issues that need dealing with, and I'm sure I'm not the only one around here that's tired of rolling his eyes and putting up with your crap.

Just about every road derailleur from Shimano today states a 27 max cog size, yet I know some people running 34 cogs on them. If you want to be absolutely safe, get a mtb derailleur, but why not try what you already have and see if it works before you go wasting your money?