Hi guys, newbie here.

I'm wondering how does something like the tiagra groupset compare to, say, 105 and dura-ace?

Now I know that it's not really a fair comparison but I still want to know.
I know that dura-ace is made to be light, while something like tiagra is made out of heavier, stronger (more robust) materials, but how does that matter in the long term? I'm talking like 7-10 years down the line, if the parts are being cleaned and serviced equally good?

Thanks!

Long ago the better groupsets were also more durable. I suspect that nowadays they are all roughly equivalent. The top end cassettes may have Ti cogs which will wear faster.

I don't have any long-term test data to back it up, but assuming we're just talking about Shimano, I would go for 105 if my primary concern were long term reliability. Tiagra has more plastic parts than 105 so it's probably not as durable. My guess is that Ultegra is at least as durable as 105, while Dura Ace may be slightly less. They will all last a very long time if you take care of them and don't mind replacing those crappy HT bottom brackets all the time.

I've had Tiagra, 105, Ultegra, and Dura Ace...I would choose 105 if I wanted long-term durability. That being said, most of my bikes have been full Ultegra and I've never had an issue with durability.

105 because it's not as delicate as dura-ace?

Dura Ace's only weak spot is the cassette. Using an Ultegra cassette, I think 105-DA would be equally durable.

My first modern-day road bike, which I still ride, came equipped with a Sora triple 8-speed and thumb shifters. After a little over 26,100 miles, it's running just fine, and contrary to popular belief, it stays adjusted quite well.

My "good" bike, a carbon-fiber model, is equipped with Tiagra triple 10-speed. With a little over 13,700 miles on the Tiagra, it too is running just fine and stays in adjustment. The Sora and Tiagra have outlasted the 105 that I had on an earlier bike.

Right, modern 105 is great! Shifts nicely and the material engineering seems less worried about being "light" and more worried about being strong...

Just my opinion, I have no hard data.

I think any of the mid or higher (105 on up) will last a long time and longer than most riders care about keeping the groupset. No reason they won't last well over ten years and maybe 20 if cared end for

I think 105 and up to Dura Ace is going to be just fine for the long haul. I will say my new (ish) 105 11-sp is really good. Like, really good.

All shimano groups are fine for the long haul.

The higher end Shimano stuff is more durable IMO.

Depends on the component you're talking about, but high-end Shimano is CF, lightweight etc Will last longer, materials are better.

If talking about a cassette or chain...cheaper is better. Might last equally long, but the price difference between 105 and Dura Ace is so dramatic, I'd downgrade on my bike!

Someone suggested I read this: Art's Cyclery Blog » Shimano Road Components ? Where to Spend Your Money

For MTB, Deore (not XT, LX etc, just plain Deore, class up from Alivio) is the most durable in my experience.

For road, 105 (or even Tiagra) is the "sweet spot".

I'm a fan of lower sprocket numbers, because up to 8 speeds at the back seems to be less sensitive to play in RD pivots and dirty/worn cables and housing. I've had very good experience with Shimano Claris road shifters, though derailleurs were Sora clas and brakes were Tiagra.

One of my bikes has late-90s nine-speed Dura Ace which remained perfectly adjusted with embarrassingly little maintenance. Cassette wore down quickly, but that's because several of the cogs are Ti.

In terms of performance, modern tiagra is about the same as 10 year old dura-ace.
In terms of durability, the higher end groups have better quality wear surfaces and will last longer if properly cared for.

You are saying that 4700 Tiagra is about equal to the performance of 7800 Dura-Ace.

I gotta disagree with that.

Mechanically, 4600 and 7800 are very similar. I've taken both apart, but some of the materials used, especially in the inner workings, is different, 7800 having the lighter/more exotic materials like carbon and titanium.

I haven't had either for a longer period of time, so can't speak about long-term performance or durability, but it's difficult to tell the difference other than if you held one in each hand you could tell that 7800 is lighter. I am having to repair the 7800 right shifter, so perhaps that speaks to the durability of the unit, at least in my case.

Everyone is entitled to their opinion. Mine is based on owning and riding both regularly. In terms of shifting and braking performance, there is little difference between them except the tiagra is less smooth when downshifting from the big ring.

The dura-ace is lighter, but being 10 years old it doesn't seem to elicit the looks of envy it once did.

Envy doesn't have any affect on performance.

7800 is awfully good stuff. but if you are comparing a new groupset to one with 10 years of service, I guess that would make sense.

Have you ridden both groups?

Yes, have you?

I used 7800 for 70k miles, and test rode a couple 4700 bikes(purely for frame fit).

4700 isn't junk, but it didn't feel as smooth as 7800, and I doubt it would last as long.

no under tape wrap for 7800 made it feel smoother, 7900 feels substantially worse than 4700

What parts would wear faster?

My experience is 4700 and 5800 shift about as well. I find 6800 to be significantly smoother than both: very short lever throws, very fast shifts.

Man, that sucks. DA should be top of the line all the way.

High end groups don't seem to last any longer than low end stuff. Especially when switching from less speeds to more speeds.

The simplest, first thing that comes to mind is a cheap 30$ steel chainring crankset, compared to a lot more expensive aluminium chainring crankset. Yes, the new, hollow axle alu one will be lighter, but less durable and a lot more expensive.