1980 Trek 710 bottom bracket?
 

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Trek 710

What bottom bracket do I need for this? I almost bought an new old stock Campy 111mm/ITA Triple 10 speed but realize I have no idea that I am doing,

I have not taken it out of the box yet and just noticed a dent. Can that be fixed?

Your bottom bracket choice depends on what crankset you’re using.

You’ll at least need to post pictures of the dent to get any opinions on that. Having someone qualified look at it in person is better.

English threaded 68mm, Length/type depends on the crank you choose to use.

Make it a single front chainring and use a Hollowtech2 68mm BB then just use spacers to figure out your chainline. They still make 9, 10 and 11 speed freewheels. Most likely you would need 2 spacers on your drive side and one on your non-drive side. Super easy clean set up. Set it up with a derailleur hanger if you want more range and a more modern derailleur. I like to use one on each side with the non-drive side hanger as a spacer so the wheel stays even in the dropouts. Just grind the threaded part off and flip it. Is that a dent in the chainstay or is it like that on both sides?

Are you talking about the dent in the chain stay right behind the bottom bracket? That is there for chainring clearance-