My son's bike (Decathlon road bike with 24" wheels) has the following configuration: Shimano Claris 3x8 STI shifters: the crank set is a Suntour 48-38-28 teeth with 152mm crank length; the cogs are a vintage Sachs Maillard, made in France, 12-28 teeth freewheel (screw on type); both derailleurs are Shimano Claris.
Now, while the rear derailleur works like a charm, the front derailleur doesn't change very well (it needs several pushes and goes directly to the third chainring, doesn't come back easily etc.) Someone explained me that this might happen because the crankset is a MTB type, and there's a wider distance between chainrings than in a road crankset. My questions:
- Is this explanation correct?
- If this is the explanation, can I replace the Claris derailleur with a MTB type derailleur (i.e. Deore?) Will the Claris shifter change properly the gears on a MTB derailleur?
- What other hacks could I try to make the bike shift gears easily? I don't want to give up the claris shifter, nor the crankset, so, it's only the derailleur that remains, apparently, available for hacks / tweaking :)