I just got a new TT bike (Cervelo P2). I took of the chain rings to clean them and reinstalled them with grease on the chain ring bolts. After a ride in the nasty weather, I decided to clean them again. This time, when I attempted to remove the chain ring bolts, I ended up breaking two of them and just left the rest as is (didn't want to break any more). Any thoughts as to how this may have happened? My guess is that it ain't the grease: i may have overtightened the bolts. Also, any thoughts as to what type of new bolts I should get? Alloy or steel or what? Thanks all!
Was it pretty cold when you rode it? Weather if it is cold then taking cold metal into a warm environment can make metal brittle along with the over tightening. Combination of both may have made them break. If you can extract the bolts and have a way to get the correct replacement size I would go with steel. Every bolt on a bicycle has a maximum amount of inch pounds to tighten. Best way and most sure fire way to make sure you do not over tighten is with a decent Torque Wrench.
Good maintenance to your Bike, can make it like the wheels are, true and smooth!
On a bike of this level I would assume they are alloy. You probably overtightened them. You really need a torque wrench working on a bike like this. There are a lot of bolts that can be under or over tightened and cause significant damage.
It's a bit unusual to remove the chainrings completely to clean them. Putting a lot of wear on the bolts when the only area that needs regular cleaning is where the chain contacts the chainring.
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