>>973653>>973659No - a bolt from a hardware store is a bad idea, you could damage the ears of your seatlug. What you need is to go to a bike shop (or shop online) for pic related, it's the proper seatpost binder bolt.
>>973667Look very closely at the rim for signs of damage, especially cracking at the spoke nipples. It's a decent wheel, whoever got rid of it probably had a reason.
