I am trying to change the first chainring on my road bike, but I can't seem to find the right allen key to remove the chainring bolts. I tried standard and metric but it is "in between" the sizes, I mean what the hell?!? I have a shimano fc-a050 crankset.
'''96 Litespeed Catalyst, '05 Litespeed Firenze, '06 Litespeed Tuscany, '12 Surly Pacer, All are 3x8,9 or 10. It is hilly around here!
The right hex key for most chainring bolts is 5 mm. Some brands now use Torx screws but I don't think Shimano does.
BTW, I looked up your crank on Shimano's web site and I think it's one of their low-line models. It's possible that the chainrings are not replacable which is why the bolts won't come off. Some of Shimano's low line MTB cranks have non-replacable chainrings so your road crank may have the same "feature".
But it just looks like I will need to replace the "fake" chainring bolts with new "real" ones. I'll take a pic and post it later. Unless you are trying to say they are welded, then its a different story altogether. But since the chainrings are available in different sizes, I don't think that's the case. I really think they put "fake" chainring bolts so that you'd have to upgrade your crankset in order to swap out different size chainrings. Little do they know we have people like me who WILL beat the system!!!