Hi guys I have a Cannondale CAAD Optimo Disc 105 that came stock with a 50/34 crank and an 11-28 cassette. I am almost positive the rear derailleur is a short cage 105 rear derailleur. This is my first road bike so I have been struggling up hills and I am on the heavier side so I know I have a while to go before I am in the best shape to tackle hills. So I am considering going to either an 11-32 or even the new 11-34 that shimano has in the new 7000 series 105 cassettes. I know I will have to upgrade the rear derailleur to a gs series. Is there any reason to not get the new 7000 series rear derailleur since I am going to have to get a new rear derailleur anyway? Are there any compatibility issues with newer components and older components? Sorry if these sound like obvious questions but I am still learning a lot about cycling.

Also would it be worth it to at this time upgrade the rear cassette and derailleur to the Ultegra R8000 series at this point and keep the 105 STI levers and Front Derailleur? I noticed there isn't much of a cost difference between the R7000 and R8000 series components.

If you're struggling up hills, but not walking up hills, I wouldn't change a thing.

As you ride more and more miles, I think you'll find 34-28 to be sufficient.

If you're walking up hills, and/or just want the gears, yes a 7000 RD will work fine with a 5800 shifter.

I am walking up hills at the moment. I hope to not be doing that soon. But for now I think changing the rear cassette and unfortunately the rear derailleur as well would be a good option to keep me on the bike more until I build up the strength and endurance to ride up hills with an 11-28.

I agree that it is worthwhile if you are walking now. You'll likely make use of that extra gearing for well-past the time when you can cycle to the top of those hills. As rides get tougher and longer, we all need a lower low. That was the beauty of a triple. What many saw as carrying unnecessary gears I always saw as carrying just enough for most rides (no granny use) but having the gears for longer and harder rides at the ready (using the granny) all while maintaining fairly small jumps between shifts.

I would. "Didn't have to walk" is a vastly lower standard than most of us would apply to any other aspect of a bike we've dropped $1500 on.

I would start with the 11-34 and a new chain. You may be able to use the RD still. I use a short cage RD with a 11-32 on multiple bikes. What is usually means is you can't use the 34x11 and 34x12 combos but they aren't necessary anyways. Size the new chain using big+Big+2. Crank in the b-screw and see if it will shift.

Or just go all out. Buy a roadlink https://www.wolftoothcomponents.com/products/roadlink or one of the Chinese knockoffs on ebay for $3 and an 11-40!!!!!! cassette for around $70. Look man if you are walking up hills now you need all the help you can get so don't screw around. There is this hard the bleep up attitude in road biking which is a good way to kill your knees lol. Get the gearing you need to actually spin a decent cadence up the hills.

I started out walking up big hills (wishing I was walking on smaller ones) I never changed a thing just kept pushing and I am to the point now that i'm riding them to the top. Some of them i get down to 10 mph or less but i also keep noticing improvement. Just don't give up and you will make it. More people than will admit have been in your position.

I would ignore the claim that you should just HTFU and pedal what you have.
Absurd.

adjust your gearing to fit your needs. That makes perfect sense. It's why cassettes come in all sorts of sizes and GS derailleurs exist.

get a GS derailleur, a new chain(needs to be longer than current), and a new cassette. Boom- easier time getting up hills.

you could also swap the crankset out and get a Praxis 48/32 cassette to help make it easier to climb.
Or an adventure crank by FSA thats 46/30. I doubt you will miss not having the 50t ring as 46/11 will still shoot you down the road quickly.


my most recent bike has a 48/32 crank mated to an 11/32 cassette. I love it as i am 230# and can climb anything with ease. I rarely use the 32/32 combo, but it's fantastic to have if needed.

I don't think I will swap out the crank just yet as I don't want to spend that much money yet. I would love to not have to spend the money on the cassette and derailleur but if it's going to make it easier to get up hills and keep me on the bike then it will be worth it.

Upgrading to Ultegra cassette and derailleur right now wouldn't make sense because once you get stronger wouldn't you want Ultegra components that fit a higher gear?

When R8000 GS & 11-34 became available I didn't hesitate. Two more teeth than 6800 11-32 helped me spin up Tour of Ca. Alps Passes this year. 6800 GS is rated to 32, got mine to work with 34 but put on an 8000 GS anyway, it shifts better. Downside is I think the 8000 GS is rated for a low gear between 28 & 34 teeth. Haven't pushed it yet to try it with my favorite flat land 12-25 cassette. There is no one "best" gearing for me, I change cassettes often to match the ride. My bike is a lot nicer geared for the terrain. And I suspect yours will be too.

For the cheapest out, try a 30-tooth cassette first - they can be made to work, as long as you don't ride big chainring with the 30-sprocket. No point in taking some of the enjoyment out of your riding over a gear ratio.

Personally, I've found the difference between 34/28 and 34/30 to be a decent gap and it may give you the ratio you need to get up over those hills.

See how you go from there before dumping a whole lot of coin.

Cheers

getting an Ultegra vs rear derailleur would be fine as it could handle a larger cassette now and handle anything smaller in the future.
but that also assumes a new cassette is needed in the future. If an 11sp 11/32 works now, then why not stick with it even later on? No harm done and dropping to an 11/28 really doesn't dramatically change much in terms of cog spacing for mere mortals.

completely makes sense. Male the smaller changes first and see how that goes.
the crank options are more a more extreme change for sure.

I genuinely dont understand where this reasoning comes from. Everyone has different strength, stamina, and weight. What one person can do, another cant. What many can do, many cant.
its why 11/32t cassettes on recreational road bikes have increased in OEM use- there is a demand.

a 250# guy is heavier than a 200# rider with 40# of self contained touring gear.
if the loaded touring bike needs easier gearing than 34/28, then the 250# guy needs easier gearing than 34/28 too.

Go for the change. I am a biggish guy myself, (by "biggish" I mean pretty freaking huge .... and not necessarily tall) and have asthmatic lungs and a questionable heart .... cracks me up when I hear the HTFU guys saying "I dropped all the way down to 10 mph." I Wish i could hit 10 mph on some of those climbs. i wish i could pedal all the way to the top without have to pause for a few beats and losing all my momentum ... but I'd rather lose momentum than blow a valve out of my heart.

Get the lower gears. Enjoy the ride, and if later on you find you don't use them, EBay them or keep them and build a touring bike or a gravel bike.

For the HTFU guys .... probably the OP would get a better workout laboring up those climbs even in a lower gear, than stopping, puffing and blowing, and then walking, so in fact, telling him to stay with the lower gears will Weaken, not Strengthen him..

I think I am definitely going to upgrade the rear derailleur to the Ultegra RD8000 GS since it isn't that much more than the new 105 RD and if I am changing it out why not go for a slight upgrade. I am debating between the 11-32 or the 11-34 cassette. I know doing this will eventually make me want to upgrade the FD and shifters to be Ultegra so it all matches haha. I am also debating on ordering the parts and doing it myself or paying the premium to have it done at my LBS. If I do it my self I will have to learn how to setup a rear derailleur as I have never done it before.

Lower gears are also often better if you're interested in going faster while suffering just as much.

The Wolftooth bit is $20- works well.

Cassette, probably chain ('tho I have a bike w/ 2 quicklinks & an added piece of chain going)

& you're set- no new RD needed.

I did this. Don't need it on normal rides, but for the epics & the 20% grades it's welcome.

Been trying to figure this out ... and this makes sense. If you find you don't need the extra teeth, no loss. If you don't get them and wish you did ... your whole effort was wasted.

Im betting the R8000 or R7000 GS would work fine with a 11-36 SRAM cassette. Here is a guy testing it with a 11-40 mtb cassette: