Swapping out my front and rear derailleurs I have been having trouble adjusting my gears correctly, so that they stop making noise and grinding in one spot or another.

Every time I set the high, the low goes and then fiddling with the cable length blows everything out.

I have a 2014 Giant "Boulder 2" which came with a Tourney TX55 rear derailleur and a Tourney TX51 front derailleur.

I purchased a Tourney TX35 rear derailleur and a new Sora 3500-B x2 front derailleur, thinking this might solve the problem, but I'm now just stuck with questions.


Will the Sora fit as my front derailleur in place of the original Tourney FD?
Will the Sora be a better option than the original Tourney FD?
Is it worth changing over to the other new Tourney TX RD, as I don't think there is anything wrong with the original?
I would like to upgrade both derailleurs, but what should I buy and what would be the next level up?
Sora is a road groupset. Road front derailleurs are all bottom cable pull (I believe), your bike (and most mountain bikes) is top cable pull, so that is not going to be compatible.

I don't think swapping a derailleur within the Tourney range is going to make very much difference. You will probably get much more value out of having a bike repair shop adjust the derailleurs properly.

Currently the Shimano mountain groupset progression is Altus then Deore (between those two, Alivio and Altus were offered in the last few years as well). 

Upgraded components will work better. You have to decide if it's worth it for you. Bear in mind that Altus and Deore are 9-speed groupsets so you'll be replacing derailleurs, shifters, cassette, chain, cable and housing at the very least. Your rear wheel hub may also have an older style 'freewheel' system rather than a 'freehub' system, if so you will not be able to upgrade.

Often, with bikes at the cheaper end of the spectrum, upgrading components is not worth the hassle, and just getting a better bike is the preferable option.