Total n00b question here, I did have a look for similar questions & answers first! I have a 2009 or 2010 Specialized Rockhopper SL with all Deore parts. The left shifter is broken. I can pay £23 for an exact replacement or £9 for the Acera. Both new and supplied with cable. Is the Acera compatible? Will it work? will I notice much difference in smoothness of changing? is the Acera very cheap and mostly plastic parts? also, does anyone have a decent link to a step by step guide of how to carry this job out, feed the cable through and make sure the chain, shifter indicators and the FD-M590 derailleur all end up in the right place?

Many thanks

2 Answers 2


Short answer - yes it will work, its a 3 speed Shimano "mountain" shifter so the amount of cable pull should be identical.

Long answer - You get what you pay for.

Acera is the cheapest of the M series groupsets. Above it you have Alivio , then Deore. In saying that, Shimano's trickle down development tends to send improvements down the production line over the years so a 2018 Acera won't be much worse than a 2009 Deore.

You won't (initially) notice much difference in shifting quality. It'll probably feel better for a while.

Yes it will be plasticky. yes it will break faster than a new Deore part. YMMV depending on what sort of riding you do.

You can find many tutorials on YouTube on how to do this ("replace front shifter bike"). With luck you just need a 4mm and 5mm Hex and to be able to get the left grip off. Worse luck, the cable housing has degraded and needs replacing too.


An answer about how to install new shifter.

Mounting the shifter and running the cable through the housing to the derailleur is easy. Adjusting the derailleur less so. Park Tool has a great article and video with step by step instructions for front derailleur setup that makes it easier.


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