Maelochs

I have a full Ultegra bike and a couple with 105. When I am riding the Ultegra bike I would swear it shifts a microminimal bit more quickly and smoothly ... and when riding the 105 bikes, I would swear that there is zero difference.

I doubt I could pass a blindfold test.

Also, I am comparing 6800 to 5800. No idea what 8000 and 7000 might be like .... but i bet, about the same, relatively.

Nachoman

I always wonder the same thing. I've owned many iterations of both. 105 is basically flawless. And ultegra is possibly a tad better.

icemilkcoffee 

This is SRAM's 'Yaw' technology:
https://www.sram.com/en/sram/models/fd-frc-b1
The FD doesn't just move laterally across the 2 chain rings, it actually changes angle as it moves. When it moves from the small ring to the big ring, the front of the cage moves further than the rear.
Now to be fair. Shimano was the first to make an STI without trim. The good ole RSX 7 speed STI had no trim function. These older Shimano brifters require you to press on the left shifter until it upshifts. In other words, you have to 'overshift' a little when upshifting. And then it settles back a little bit, and gives the chain just enough room to sweep across the cassette. It also helps that the 7 speed cassette is narrower than the 8/9/10 speed cassette, so the amount of cross chaining is less to begin with.

mstateglfr 

What tires you have will make more of a difference in your enjoyment than ultegra instead of 105. Heck, bar tape will make more of a difference in your enjoyment.
I have owned multiple generations of 105 and ultegra- the 5800 and 6800 generations were really similar, and the new R7000 and r8000 versions are simply equal for all intents and purposes.

Retro Grouch 

How thin can you slice the baloney?

How many different road component groups is Shimano making today? They all work okay, the more expensive ones are just a little bit nicer an all ways.. Functionally, as you move up the food chain, the performance improvement is pretty linear. The increase in price, however, tends to be geometrical. The Shimano marketing people want to make sure that, however much money you are willing to spend on bicycle components, they have a groupset priced to extract it all.

CerveloPro1

Like others have said, you can't go wrong with either. I prefer Ultegra. IMO best cost/weight/reliability set on the market.

Hiro11

The pricing is pretty similar, at least compared to the huge jump to Dura Ace. I have been riding Ultegra since it was called 600. To this day, I've never had a problem with any Ultegra component, it has always been 100% rock solid. I don't know how Dura Ace could be any better, so I've rarely paid for it. Who knows if Ultegra is worth the (very slight) increased cost vs 105, but why mess with success... I just go with Ultegra, always.

rekmeyata

Cooler doesn't mean squat!

I personally would go with 105, going with all Ultegra is only going to save you 7 ounces, or 200 grams depending on what scale you prefer, but it will save you around $550, so is $550 worth saving 7 ounces? HARDLY! That's over $78 an ounce difference. If you are getting a discount on the groupset as a box set then go all 105, if you can swap out anything I would swap out the rear 105 derailleur for Ultegra, that swap will only cost you $35 difference and it will provide a tiny bit smoother action, most places will do the swap at the cost of the difference as long as the 105 derailleur is not mounted and or used. The front derailleur doesn't matter since all front derailleurs shift about the same anyway.

There also isn't any difference in the reliability of Ultegra over 105, I know I can hear all the screaming, so to hush the screams of horror read this: https://biketestreviews.com/shimano-...0for%20Ultegra.
So all it boils down to is 7 ounces going to fry your legs. Having read that above site myself, I'm not so sure if going to Ultegra on the rear is really necessary anymore.

The other good thing about going with 105, if you have an accident and damage a briftor it's a lot cheaper to replace than it will be for Ultegra.

What I just wrote above I actually did with my Lynskey I bought 7 years ago, and it works great, the only other thing I did with the 105 package was to swap out the standard Shimano cables with Shimano DA9000 cables, those DA cables are very smooth operating, in fact after riding DA equipped bikes you can't even tell your on 105 stuff, the 105 stuff feels very similar to how DA feels. Adrenalin Bikes where I got the Lynskey made that cable recommendation, he said that if a DA equipped bike came with standard cables it wouldn't feel as smooth as Shimano advertises it to be and would feel similar to 105, so it's the cables that make a difference on how those components feel and operate. I can say after 21,000 miles I haven't had any adjustments, nothing, even the cables are original! I know how and what to look for in wearing cables, but they just haven't worn to be thinking about replacing them.

So after reading that site I would probably just stay with all 105 and not bother with the swap, and when the standard cables wear out replace them with DA9000 cables.

MikeEckhaus

I had Ultegra 6800 on my main bike. A couple years ago, I had the opportunity to swap out a DA9100 groupset for almost no money, so I did. Looks cools, saves a few ounces, but I can't tell the difference in shifting. The funny thing is a couple years ago I set up my spare, 15 year old bike with 5800 series 105, and it shifts better than either the Ultegra or DA on my main bike. Not sure if it's because the old bike has external cable routing with smoother bends or what, but the 105 is just so smooth on that bike. So for me it comes down to weight/bling versus cost.

Maelochs

I can vouch for this. 8000 brifters were running $200 + for Singles .... I was lucky to find an old 6800 fr a slightly less ridiculous price, but I got the wholel group set on sale from one of the English retailers for about $500 in 2015 .... five years alter one brifter was 40 percent of that.

105 is consderably more reasonable to replace.

Camilo

If money is a factor, just get whichever parts fit your budget. They all work extremely well, even Sora. If you just want, and can afford better parts, that's a good enough reason to go for Ultegra or Dura Ace (or SRAM Red, or Campy Super Record, or electronic shifting..). Good enough for me, anyway. It's fun using upper or top tier stuff just because it's fun.

I happen to be a SRAM guy - but won't buy into the SRAM rulz, Shimano drulz, Campy is King nonsense. I use SRAM because the ergonomics of the levers and the shifting action suit me best. Functional differences are trivial at best and not a meaningful factor at all.

veganbikes

The idea of this thread which people are missing is some new person just is killing posts so he can post a picture in his own post. This is not meant to be meaningful discussion on 105 vs Ultegra more a skirting of the rules and space taker.

Also Suntour is the best clearly

Beach Bob

IMO, if you're happy with mechanical shifting, 105 is more than enough, if you want electric shifts, Ultegra DI2.... if you're sponsored.. .Dura-Ace (if the pockets are deep, DI2....). I don't think that 90% of us mere mortals would be able to tell the difference between Mech105 and Mech Ultegra...

sw20

I've got full Ultegra r8000 on my bike apart from the calipers which are r561, have been wanting to upgrade the calipers since owning the bike, new r8000 calipers will cost me about £120, used will cost about £80, I can buy new 105 r7000 calipers for £60, other than a tiny weight saving and badge, is there any noticeable difference between the 2 in terms of braking power? Not sure if I would always want the r8000 if I was to buy the r7000, but the fact I can get brand new r7000 for half the price of the r8000, is swinging it for me!