Specialized Hardrock running gear

[huw3md]

My son's Hardrock Disc is still on the original 7speed Sram running
gear and to cut long story short its done a lot of work and it needs
replacing.Any suggestions on upgrading to 9 speed Deore or
similar taking into account he is fifteen and works weekends in the
local pub washing dishes.

[dyls]

I'd go to a bikeshop and get their advice.

I don't think you can put a 9 speed casette on a 7 speed freehub. Then you have a narrower chain which could require changing the front chainrings, not to mention the shifters. Again not sure whether you could use a 7 speed deralier/keep the front derailler (indexing).

I'd probably upgrade but stick to 7 speed.