smasha

Gravel bikes tend to be drop-bar, which tends to change the geometry. Perhaps more importantly, the only gravel-bike I can think of with a fork that would be good for a low-rider rack is the Giant Revolt, but that's a carbon fork.

MinnesotaSteve

Well I got further with my 2020 Trek FX3 improvements...

I replaced the crankset with the M4100-2 to get the lower gear ratios. Had to shorten the chain for this, but no big deal. I haven't had a chance to ride this yet as we still have a ton of snow on the ground, but the weather has warmed up and I'm hoping in a week or so it'll be better.

So in looking at the rear shifting and why it appeared sluggish, I did get the Alivio M31000-R shifter. Someone else here in this thread mentioned it was snappier than the Acera, and I'd have to agree. But I also think I found the source of the issue I was having. The old shifter cables, as they went down below the bottom bracket cable guide, Trek had placed a short piece of inner housing liner, like 6" long or so. Anyway that liner was torn and was kind of jammed in there constricting the cable. I'm not entirely certain what the point of this was, I don't think it's needed. Anyway, after having done that I decided to just go ahead and also get the Alivio M3100-L shifter. That's a single lever shifter, also works really well.

I then looked at the front derailleur and wondered if I should upgrade that, but this is where my research gets weird. The current generation MTB like Alivio and Deore front derailleurs are side pull, which means the cable has to come from the front rather than the bottom. That's not how the cables route on the FX, so that was out. I looked at some older stock shifters, but eventually decided to just keep what I had. I had to lower it and realign everything and I got it working.

I went through the process of readjusting everything on the rear derailleur and it seems to be working really well right now. I'll have to check it again after riding it as the cable will likely loosen up a bit. But I want that snow gone.

hokiefyd 

I don't think you'd really gain anything by changing the front derailleur. You're right that you'd need a down-pull derailleur (or at least a dual-pull, capable of either top-pull or down-pull), but there really isn't much to the front derailleurs -- they're just a brute force mechanism to force the chain to certain chain rings. If you can get your current setup tuned so that you don't have much, if any, chain rub on the derailleur cage, then you're doing well and I'd leave it as-is.

MinnesotaSteve

Yeah, after I took the time to really dial in the front derailleur it's working very well.

I'm still curious why they had that liner in there. There was also one on the front shifter cable too, and it had also split, but hadn't torn and gummed it up.

MinnesotaSteve

(42-11) + (40-22) = 49T... I don't know if there are any rear derailleurs that can manage that. Looking at the specs they are like 45T capacity and max of 36 in the rear if running a triple. At that point, I'm not sure what 10 speed would gain you over classic 9 speed, you'd just lose that one gear, but 22/36 is still pretty good ratio. 9 speed stuff is extremely common, utterly compatible and bullet proof. That'd still give you quite a range. So anything new or used with 8/9 speed rear hub could be made to work.

Any of the Trek FX2 going back many years would work, if you can find the right bike. But they had alloy front forks with rack mounts.

hokiefyd 

What's under the bottom bracket now that the liner is removed? Does it have a plastic cable guide that screws to the bottom of that housing? If so, you should be fine -- I presume they added a small section of liner for even smoother action, but that apparently aged poorly. Many bikes don't have the liner (they just have the plastic guide).

travbikeman

I remember a few years ago I did purchase Alvio M4000 shifters to replace the Acera M390's I had on my prior Specialize Crosstrail. I did notice a difference in the tactile feel, partly due to the better shifter and partly due to the Acera was kind of worn out already after a few years usage. Also remember liking that I could up shift 3 gears at time over single at a time on the Acera.

Noticed the specs on the Trek FX 3 Disc had the Acera M3000's. Always thought those were same or at least very similar to the Alivio M3000's, so interesting to hear it does have a different feel to em.

MinnesotaSteve

Honestly, it could just be that the Alivio shifters came with optislick coated cables. But it does feel just a bit more solid.