BHBiker

I noticed with Shimano cassettes (well at least the Ultegra group) has varying teeth configurations like 11-23, 12-25 and 12-27.

I have the middle config (12-25)but would like to purchase a new one for a new set of wheels I have. What would be ideal for a novice like me who is not racing but frequently rides on a 50/50 combination of hilly and flat roads averaging 100-150 a week depending on work commitments?

Treefox

Depends what you want to do and how well you do on hills, as well as what you've got up front. A 54-11 combo isn't going to get used a great deal by most people.

goaliedad30

I run 52/42/30 up front, with 12/27 in back. I'm old & slow & need all the low end I can get for hills! :-)

digger

Knowing what you need in a cassette comes with experience. It's difficult to give advice based on "50/50 hilly and flat" without knowing your skill level, age, fitness level, terrain, front chainrings, type of bike, etc. Novice is pretty broad term also, but since you are talking about gearing and the # of teeth on a cassette then my assumption is that you are not THAT much of a novice (?)

On my first road bike, I started off with a 11-23 in the back, but with some knee troubles after the second summer I went with 12-25 and the knee problem went away. Go figure. I've been using 12-25 ever since (15 years). That's using a triple (52-42-32T) by the way.

My touring bike has 48-36-30 and 11-32T on the rear and 15% grades are no problem.

My mountain bike has 32-22T on the front and 11-32T on the rear, I never use the 44T ring on the MTB so I replaced it with a bash guard.

So what chainrings are you using up front? What type of bike?

BHBiker

sorry for the vague description of my set up there. i am using the Ultegra chainring with 53/39 teeth double. I am on the heavy side 195 lbs/ 5'9" height but reasonably fit (no high blood prssure or diabetes yet :-), 31 years old. Its a road bike.

vpiuva

This diff between the 12-25 and 12-27 is loss of one intermediate cog to gain a better hill 27 tooth cog. Sounds worth it to me until you're down to ~165#. Do you find yourself in the 25 and looking back at the cassette for a bigger gear sometimes?

BHBiker

actually thats why I asked. In the first 500kms I was literally gasping for air going up the steep inclines but right now due to a consistent bike-to-work change in my lifestyle, I barely use the 25 cog. My LBs said its like an emergency cog you can use but I feel that I am slowly graduating out of it. I am thinking that an 11 teeth might be more useful for me in increasing speed on the flats without going on the bigger front ring. Am I right on this assumption?

Bill Kapaun

"...I am thinking that an 11 teeth might be more useful for me in increasing speed on the flats without going on the bigger front ring. Am I right on this assumption?"

Then you are cross chaining which isn't recommended. The Big Ring is for the flats!
Do you spin put with the 52-12 combo? If not, going to 11 doesn't really do any good.

"...I barely use the 25 cog."
Which means you still use it!
My theory is to always have 1 gear lower than you would expect to use for 99% of your riding. It's that 1% that bites you.

BHBiker

thanks bill! I am going for the 12-25 then. I really appreciate the inputs here. It makes me more knowledgeable and my hard earned bucks are well spent :-) cheers guys!

Bill Kapaun

My thoughts were that you already had what you need, gear wise.
Sometimes the grass just seems greener...

BHBiker

he he he i know,..just making sure that the optimum cassette will be sued for the other wheel. cheers matey!

BHBiker

^ used i mean

digger

Then I'd stick with 12-25T and I suggest you consider 12-27 for the extra help on the odd REALLY steep hill.

53-11 is a pretty hard gear and my thinking is that you won't use it and IF you do, it will only be on fast downhills, and I doubt 39-23 is low enough for climbing.

I switched from a triple to a compact crank (3 days ago) 50-34T as I never did use the 52-12 much on the triple. Haven't tried the compact yet, jeez, I hope it works out.