Road Cycling - Road Cassette size help

My bike came with a 12-26 rear cassette.

I live in an area of rolling hills, I never use the 26, and in this area, I never have reason to leave the big chainring(53). To prep for a potential 12-23, I've haven't ridden anything larger than a 53/21 for weeks. Now I'm thinking that maybe a 12-21 would be a better idea. Though I may have to use the 42 with that combo.

Since I'm thinking of doing a couple races... obviously a 12-21 would be find for anything that I've ever ridden around here and good for Crits. NOTE: I've never rode in mountains or REAL hills. The longest hills here don't go more than 1.5 miles as the grade isn't very high.

One other note. I am running an SRAM 12-26 right now. I've heard that since the cogs are seperate, that you can essentially "create your own" cassette with two. In THIS case, could I actually buy a SRAM 12-21 and construct my own cassette for my riding situation? So I could create anything out of a 12-13-14-15-16-17-18-19-21-23-26?

I need some advice... I had placed an order for a 12-23 at Performance and would need to change it early monday morning to a 12-21. If the "swap out" cogs work, it's a no brainer.

I'm just thinkin that the 18 would be nice to have

I use a 12-21 around here and I love it. The 39-21 is more than low enough for me on any climb within 25 miles of my riding area ans the steep ones are less than 1 mile long so I can power over them pretty well.

I love the 12-21 since it is close to a straight block of gears. Making one toorh increments does not radically change your pedal cadence and is easier to stay in a good rythm.

When I go to the mountains I use a 12-26 like you have but around here I would never use the 23 or 21 tooth cogs unless I was near death or exhaustion.

The SRAM 12-26 I have is a complete assembly that is not broken down into individual cogs. It is a 2004 series 9.0.

Perhaps the other models come as individual cogs. I am not sure.

are you spinning at all?

if the lowest gear you ever use is 53x21, then you must be grinding up those rolling hills. moreover, in a sram 12-26 cassette, that combination has you very close to cross-shifting. you'll spare your chain, cassette and chainrings a whole lot of wear by using the 39x16 instead.

save your knees, use all your gears. learn how to use the front derailleur.

having said that, a 12-23 is a perfectly good cassette. it gives you a straight block up to about 17t, and enough bailout gearing for most rolling hills.

As for climbing the hills in a big gear...it all depends on how fast you're going and how steep the hill.

A racer that I ride with told me that I was spinning too high on the hills for our area. He said that it was the reason I was getting exausted in trying to keep up on the long hill. Another guy said he couldn't ride behind me because I was spinning so fast. I was told that i was going anaerobic by spinning this fast on the hills.. and that if I sat back in the seat and "powered through them" that I would be able to keep up. I tried this on the following weeks ride, and I was able to stay with the front of the pack. I started this on my solo rides, and noticed an improvment in average time.
He had recommended that if I'm sitting and feel the need to drop to the 39, then STAND.

Was this bad advice?

My SRAM 12-26 are all individual. I've taken them off to remove the "frisby" spoke protector on my bike. It's a 2004 Cannondale.. perhaps it's a 03 SRAM? We'll soon find out.

He had recommended that if I'm sitting and feel the need to drop to the 39, then STAND.

Was this bad advice?

It depends. 10 years ago I came into cycling from powerlifting. At 170 lbs I was capable of a near 600 pound squat. In those days I rode with low cadence around 70-80 rpms and could power over any hill around here in a 53/17 or 53/19. But cycling was new to me and my quads had not learned to spin yet.

Once I learned to spin at 85-95 rpms I turned better times on my rides and was less fatigued. I no longer just rode the big ring and could run up hills quicker.

My cadence zone now is anywhere from 90-115 rpms on flats and rolling hills and 75-85 on long climbs unless they really kick up beyond 7% grade.

Now, what does this mean to you?

Find your ideal zones for yourself. What works for somebody else may not fit your riding style. Yes, climbing in lower gears at high cadence is more efficient unless you get outside the zone that fits you.

You can train your body to ride at higher cadence but it takes time and determination.

Keep one thing in mind, if you are trying to keep up with the guy in front of you and you are overgeared and turning low cadence of say 75-80 and he is in an ideal gear turning say 90-95 rpms it is unlikely you will be able to hold onto him if they accelerate hard away from you. you will be bogged down and working to build speed where he will gain more speed quickly then simply shift gears as his cadence climbs past his ideal zone. Imagine two cars of the same size and power at a stop light. One starts in second gear and the other in first, the car in first gear will accelerate away quickly.

I live in an area of rolling hills, I never use the 26, and in this area, I never have reason to leave the big chainring(53). To prep for a potential 12-23, I've haven't ridden anything larger than a 53/21 for weeks. Now I'm thinking that maybe a 12-21 would be a better idea. Though I may have to use the 42 with that combo.

Since I'm thinking of doing a couple races... obviously a 12-21 would be find for anything that I've ever ridden around here and good for Crits. NOTE: I've never rode in mountains or REAL hills. The longest hills here don't go more than 1.5 miles as the grade isn't very high.

I'm just thinkin that the 18 would be nice to have

I also live in a pretty flat area, and I use a 42 which is handy for easy days and riding into strong head winds.

I assume you have 9 speed?

If you're going to do some racing, you might even want to consider an 11, therefore having
11 12 13 14 15 16 17 19 21. Occasionally you'll be doing a criterium with a hurricane of a wind, and each time the wind is behind you, the pack could be pushing 40 mph. Some people who aren't great technically with the pedals, get caught out on a 12 tooth cog at high speeds, and it's also nice if you don't feel like riding at 110 rpm, you can just cruise on the 11.