On my fx3, the rear derailier, is acera, but on the website , it says it is supposed to be alivio.
I chatted with one of the trek people on the website, they say it is interchangable and it depends on what is available at the time.
I bought this directly from a trek store, and i'm just curious is this normal?

shouldn't it be alivio, since i thought alivio is step higher

Thread moved from Great Lakes regional forum to Hybrids forum.

They are both lower-end mechs and I doubt that you would notice much of a difference. If they are set up right, they both will perform adequately.

Nothing wrong with making a fuss, though, if you think you've been mistreated. Instead of chatting online with the low-paid menu reading support staff, talk directly to your dealer. If you make a big enough stink, they may give you a bit of a credit to make you go away. Price difference is something like $10, so perhaps you can get a water bottle out of it.

Interestingly Trek's site does have Alivio for the rear derailleur in description, but the images shows the Acera.

Reality, the M3000 Alivio isn't that much if any different than the Acera and Altus. If it was the M4000 Alivio, I might then agree with you, but the M3000 isn't even that much different than the Altus rear derailleur with how it shifts and even looks.

I did notice a slight difference in shifting when I had the Alivio M4000 to the Altus. The Altus was a slight slower shift. But when I tested this Acera your FX has a few years ago when testing a Giant Toughroad, I don't think there is much of a difference at all as compared to the Alivio.

Personally, I wouldn't think too much into it and just go ride the heck our of the bike and enjoy.

(side note, it doesn't make much sense for Shimano to have three 9 speed rear derailleurs that all perform similarly, it's confusing to the customers whom buy these bikes)

Really think the rear 10 speed Deore that is non clutched should now be the Alivio and drop either the Acera or Altus and have 1 rear 9 speed derailleur.

Note that all bike manufacturers' websites state that components can change at any time and without prior notification. It's very likely that, due to the tremendous supply chain disruption over the past year, Trek had to use the nearly identical Acera rather than the Alivio that the original spec sheet may indicate. The bike will operate just the same regardless, mechanically. You should not notice any operational difference between these two derailleurs, assuming both are adjusted and indexed correctly. There are styling and very small material differences but they are otherwise functionally the same.

If you're stuck on the principle of the matter, beyond Trek's disclaimer that parts can change without notice, then perhaps you can get some credit back from them on it. I think there was a recent case where Trek was using a lower-spec tire on a bike and some folks here complained and Trek sent them some new tires.

At that level it doesn't make much difference but don't most bike companies have some fine print on their component descriptions that basically say subject to change whenever we feel like it and without telling you? If it were me I would not choose this particular battle.

It is partly the principle, if they can prove it is similar component then i guess not soo much, but also, i do notice as i had created a thread below, that certain gears, when in the big chain ring in the front, don't allow for the rear deraileur to operate as smoothly. but i 've never had shifting problems, I hate to go through the hassle, but it might be worth it to address my concerns described below.

Bigger chain ring on 2x - Bike Forums

No I don't think you got scammed. Good luck with the bike. I had an fx3 about 10 years ago. Really enjoyed it.

There are lots of notes of parts supply chains being scrambled recently due to the pandemic, as well as restarting the economy.

I think it is good your bike came with a rear derailleur.

If it gives you trouble in the future you can upgrade to one of the Deore models. Just be careful with the speeds.. You must have a 9 or less speed derailleur with any 9 or less speed drivetrain.

Interesting you brought that up, most of the bike is acera components, what would be involved to move up to Deore, and what would be the cost of the parts and labor?
Would i just upgrade the shifters, derailers (front and back) or something else as well?

As travbikeman eluded to earlier, Shimano have at least three 9-speed Shadow-style derailleurs: the M4000 (Alivio), the M3000 (Acera), and the M2000 (Altus). Alivio has recently been re-numbered to M3100, so maybe you can count that as four 9-speed derailleurs now...and this is just in their MTB range. They probably have another one or two in their road range. They're all functionally the same (at least the ones in the mountain range) but will differ in small details like styling touches, small differences in materials, etc.

Because the shifting is smooth in both front chain rings, I'd say it's not likely anything the derailleur itself is doing (or not doing). It's possible the derailleur hanger, which is the shiny chrome-looking piece bolted to the frame to which your derailleur is mounted, could be bent. This might allow the right chain angle while in the small ring, but a non-optimal angle while in the large ring. It's hard to say without seeing/hearing/feeling it for ourselves. It's almost certainly not related to the derailleur being an Acera vs. an Alivio, though.

Why not just ride the heck out of your new bike and upgrade components as they wear out? It's a lot less money and hassle. Unless that's your jam; then go for it.