Hi

First time poster... I purchased a new MTB in April, a Giant Revel 1 - it was only £450, not a serious machine like I guess some of you have - but budget is limited, and I wanted a new bike - Giant kindly offered a 1 year service deal (as many times as I wanted) but it's a 75 mile round trip to the dealer so while useful, I don't want to go every week...

Question is, it has Shimano Acera 24 speed drivetrain which I believe is one of the cheapest on the market - and whilst I don't pretend to understand the difference between them all, virtually every 50km or so, my gears need fine-tuning as I can start to hear metal-on-metal even in the middle gears. I am loathed to start messing around with the set-up myself as I'm not an expert and I fear all I would do is make them worse!! But is this normal? Should I expect better/longer from my gearset without having to tune them again? Should I consider upgrading once my 1 year service period is up - would this improve things? If so, upgrade what to? Would a better quality drivetrain actually mean I don't have to tune them as often?

Sorry if stupid questions! Go easy on me!

Hope someone can help with advice...
thanks