I wouldn't do it (move down to a compact double), but that's just me. When I ride the Lemonster, I don't often go into my triple ring, but when I do it's either that or walk up hills, and I really don't like walking up hills. Of course, with the bent I have no choice. People who don't have triples on their bents live in Florida.

I can only speak of Shimano. To my understanding, and this most certainly might have changed since, you can get a 12-30 in both the Tiagra and Ultegra lineup. The Tiagra came first and I purchased one last year off eBay as a trial to see if it would work with my Dura-Ace and Ultegra mid-length cage rear derailleurs. The Ultegra 12-30 was "announced" and appeared on the Shimano web pages, but nobody had any yet. I tried the Tiagra 12-30 out on my bike, the shifting and chain length were fine, (I had previously used a 11-28). So, I sold the Tiagra to a fellow BF member and went on the hunt for an Ultegra 12-30. Of course, nobody had any. Not even eBay vendors.

Armed with a printout of the Shimano spec sheet, I went into one of my favorite LBS, seeking to order one. It is just a one-person shop. The fellow is the owner, does sales, and all the repairs/service. He does it all. He did not believe that a 12-30 was available, and it so happened that one of his suppliers was in the shop at the same time. The rep said he would check his inventory, and after booting his laptop, said that he had ten of them. The shop ordered two, one for me and another for his shelf. When they came in, I went ahead and got both of them. (I think he charged me $100 each, tax included.)

This was about a year ago, or just under. Today, most shops still do not stock a 12-30. I did get one about a month ago off eBay. It was a decent price also, $75 with free shipping. If you go with Tiagra, they are less than half that price, but personally, I didn't like the Tiagra. There is a world of difference between the two lines.

So, they are available. You just have to hunt around. Readily available on eBay, special order from your LBS. If you go to your LBS, be sure to take a printout of the Shimano spec sheet so that they cannot refute they even exist. Good luck. They are a nice cassette, (I'm not really too concerned about jumps between cogs).

- - - - -

edited to add:

https://www.shimano.com/publish/conte...0.-type-..html

PDF spec sheets at top/right of this page under "Technical Documents".

I went from a Shimano Triple with a 30 x 27 low gear to a Sram Compact with a 34 x 32 low gear. My Sram works well and is actually a lower gear than my Shimano Triple!

Rick / OCRR

I went back to make sure and I didn't see anywhere that the OP said he was going to dump his OCR. He is going N+1 as I read it and most bikes he wants to ride seem to be sans triples. If he already has a triple and the N+1 bug hits why not go with the double? If he ever got the bug for electric shifting would any of us say, don't do it till they come with a triple? I say go for it, take a walk on the wild side, by a shirt other than white and a suit other than black and eat ice-cream other than Vanilla.

If you want the same gear range on a compact double as with a triple, a 50/34 with a 11-32 cassette (SRAM WiFli) has the same high and low gears as a 50/39/30 triple with a 11-28 cassette. https://tinyurl.com/mnt3bbt

A 50/34 with a 12-30 cassette (Shimano Tiagra or Ultegra) will give up just a little bit on both ends. May or may not matter to you. Gear spacing will be a little wider on either compact setup than with your triple. Again, it may or may not matter to you.

50-34 compact crank and 10 speed 11-34 cassette, 105 group with an LX mtb rear derailleur.

This is the gearing/setup I'm currently riding.

Started with a compact 50/34 with a 12-25 cassette, and being new, out of shape, slow and fat, couldn't make it up any hills. Swapped to the 11-34 cassette and the MTB rear derailleur, an instant improvement that I'm still enjoying today.

I would like to try a triple, just to see what the difference is. But honestly, one tooth spacing or tight gearing, had me constantly shifting up twice or down twice to reach gearing that was comfortable for me. Now, I only have to shift once on most rolling terrain or riding in wind. All my normal rides are using the 50 chainring, I only use the 34 for climbing hills. And on short hills, I'll stand and stay in the 50.

To the OP......... Bottom line, a compact double is very manageable. It won't leave you hanging if the cassette is matched to your terrain and physical ability. There's a lot of different opinions on gearing, most of this applies to the individuals riding style and level of fitness.

A recent article in Bicycling magazine stated, most people ride bikes that are over geared. If you can't spin up hills and constantly have to stand to gain leverage in the lowest gear, you are over geared.

As for Sram vs Shimano, try before you buy. Myself, I prefer Shimano. Couldn't get use to the double tap and didn't like the exaggerated lever motion.

Shopping for N+1 is always fun, have a great time and hope you find the bike of your dreams.

The chief reason why triples are difficult to find are two - one with 10 and 11 speed casettes, you have a choice of 20-22 gear ranges. That's comparable to the older 3X8. The second (and I know many people will strongly disagree) is the majority of riders feel a triple is more finicky and shifting between rings isn't as smooth as a double.

Manufacturers want to cut down on choices to save money. Without demand, many cut back on triples.

Gasp!

I have a set of wheels that will only take 10 speed cassettes--Early Shimano Ultegra. It will not take the Tiagra 10 speed cassettes. There are two types of cassettes around so ensure that your freehub will take the Tiagra type cassette before you buy. All my other wheels are 9/10 speed compatible and the Tiagra will fit fit on any of them.

On the triple- I usually run a 12/25 cassette. The wider ratios on the 12/27 annoy me a bit and I thought the 12/30 Tiagra would be worse. Only used it in anger on one ride so far but when I needed the 30t--wider ratios were the least of my worries.

And yet the MTB is fitted with a 9 speed 12/32 cassette and I never notice the wide ratios. Once again when you need those lower gears- -You need them above any other foibles you may have.

This. I tried a compact on my Volagi but didn't enjoy the 11-32 spacing. I found a triple on ebay, changed to a 12-30 cassette and I'm good-to-go up just about anything. My gearing got just a bit lower (still use a 30t small ring), but the 52-39 is just a nice pair of chainrings in which to spend most of my time.

If I may ask . . . what chain are you using, and what cassette? (which level component group) Does the LX RD work seamlessly with STI 10-speed shifters, (105 - Ultegra - Dura-Ace)?

There is a particularly steep hill I want to assault this year, and a 34-34 would sure make it much more possible to defeat.

The Deore LX SGS RD-M591 works well with a Shimano 10-speed chain and an 11-32 Sram Cassette. It has more than enough capacity for a XX-34 Cassette.

Out of idle curiosity, which hill is that?

I know! I know. I'm a wimp. The ski lifts at Baldy. Not too long of a climb, just four miles or so. Took the car up last year, just to scope it out, and some of those ramps were pretty steep. Glad I had the "powerful" car because I don't think my 74-hp diesel would have made it up. I've also been wanting to do Tioga from Lee Vining to the park entrance, but expect that a 34-30 or 34-28 would be plenty for that one. It's not really all that steep.

I think that's it right there.

I'm renting a Toyota Yaris while my bugeye Subie is repaired from that deer strike. It is one of those new cars with the binnacle centered on the dashboard. Functionally, it's unquestionably a step in the wrong direction IMHO. So why do it?

On each auto, is it much cheaper to put the binnacle in the center instead of in front of the driver, where it belongs? No.

But across an entire line of autos sold in different countries, some left hand drive and some right hand drive, it's probably cheaper to produce because it eliminates the need to manufacture, distribute and manage two dashboards, harnesses, and the like.

As far as what someone called the "endless debate about two versus three." I think it all comes down to cost. If you like hills and can make the conversion for a price you're willing to pay (or you're building from scratch), a triple is the best way to go. If you want lower gears for a lower cost and are willing to put up with the spacing and more shifting on the front chainrings on flat terrain, go for the double.

Actually, two things... you're right, I didn't say in my OP but, yes, I would be giving up the OCR for the Felt (or whatever). So, (N-1)+1. The original crank on my Giant came with a 50T big ring. The Ultegra had a 52T. My cadence and rhythm in general have evolved very nicely around the 50, so I swapped out the ring and am still using the 50. So, I lose nothing there. I did run the 30/38 vs the 34/30 through a calculator and I think I give up maybe an inch? OK, a bit more: 28.14 vs. 29.76. In real terms, I don't know how noticeable the difference would be. OTOH, SRAM WiFli would give me 27.9" plus the satisfaction of living with SRAM. Then, I don't know if the Z3 has a WiFli option.

Wimp? That climb kicks my arse every time! There is only one section that eases up a bit, and the top section (in the parking lot) is so steep, skiers call it the "bowling alley" because even with chains, cars find themselves sliding down the hill, brakes locked.

That hill ripped apart the ToC competitors last year. No shame in wanting the right gears for that climb!

Hard to say which one is worse ... that or Deer Creek. Deer is a little more unrelenting, but the Ski Lifts has the Bowling Alley.

They both kick my butt!

That's my baby! The top of Twin Peaks looking out toward The Rock, Alcatraz.
Not even a Defy, that line wasn't to be released for another year or two.
I still love the bike. It feels good and, after 6 years we know each other pretty well.
At this point, it has 8 or 9K miles on the frame. I've replaced the calipers, the brifters, the crank and the cassette. Oh, and the saddle.

^^^This^^^
And for really hard stuff you can still go with the 30 cassette or higher. Don't give up the triple

The real question is rather simple. Does the Z3 come in a triple? If the answer is no the debate is moot.

Why do you say that? A good LBS would work with him to swap it out at a reasonable cost.

If you find a good LBS (preferably 2 or 3 of them) that care about getting you what you want, you can find a nice bike with gearing you like. If you can barely push a 30T/28t up a long 10%, then IMO you ought to look at going lower. At best with a compact you can stay the same. For those nasty Bay Area hills, I love my 48-36-26 with an 11-34 in the back, but many others can get up those nasty hills without such low gearing.

I believe you CAN find the bike of your dreams, but the true bike of your dreams will include the gearing you like. Don't compromise. If the LBS isn't working with you to get exactly what you want, find another LBS. If the LBS looks down on triples, find one that doesn't. Even if you end up with a compact, buy from someone who cares about what you want, not someone who thinks what you want isn't studly enough. My LBS swapped out my rear cassette and derailleur for zero cost to give me what I wanted, and didn't make me feel bad for what I wanted. That bike of your dreams is out there, even if the LBS needs to swap out components for a reasonable cost. Get what you want, not less than what you want.

But not with SRAM.

Without doubt with the right cassette choice you can make a compact work as well or almost as we'll for climbing. But you still have the 34 tooth chainring problem for cruising flat ground.

I'm confused. I thought it came with an Ultegra compact double set up. He wants SRAM?