Hi. I am changing to a new chainring (I believe in a bmx it is a sprocket, instead). Anyway, it was difficult from the drivetrain side so I worked from the opposite side, I was able to remove the "pinch" and the other bolt but, this other bolt that goes on the spindle of the bottom bracket "stripped" the threads. I don't want to buy a new bottom bracket; can you please tell me how to fix this kind of situation. I believe the way is to tap a new thread but, I would like you guys confirm this to me. Also, what size should be the threading tool. Note, I use the " because I am not sure those are the proper words or proper spelling.
P.S. what torque to tight and which tighten first, the pinch or the "other" bolt.
Thank you all so much, in advance.

We need to know what type of equipment you have - BMX is not enough. Need a picture or the brand, year, model of your bike.

Some BMX cranks use chainrings (usually 4 or 5 bolt rings) while others use sprockets.

I'm guessing from description you have a splined American setup.

Stripped bolt could possibly be removed with an easy-out.

You tighten the bolt entering the end of the bottom bracket spindle first, and only while the pinch bolt is loose. Then the pinch bolt, of course. Not sure of torque specs, they may vary by make/model of cranks.

Well, for assembly it all together again the only thing on my way are the stripped threads inside the axle of the bottom bracket and my question is if there is a way I can tap a new thread again and what is the size of the tool. Or if that is not possible I guess my other option is buying a new bottom bracket but, I would prefer rethread if that is possible and I just want anyone to confirm and the size of the tool. Thanks,

Without knowing EXACTLY what you have, and maybe adding some good photos, we can't help you. There are too many variables and too many "standards" in the bike world for us to tell you how to proceed based on the scant information you have provided, the fact that we can't read your mind, and some hideous sentence structure.

Ohh, the crank bolt threads are stripped, sorry misread the first post. You could tap some new threads but BBs are so cheap I'd probably just replace the bb

If you want assistance you need to help us as well. Again - we need to know exactly what you have if you want to know exactly what you can do. A photo would be best.

Thanks guys, it all helps.

BMX bottom brackets no longer come with spindles. The spindles are sold with the arms as being the crankset, the bottom bracket is just the bearings and spacers. They're sold this way, because there's three different types of bottom bracket currently in use in BMX, plus a fourth legacy design.

What brand is the crankset? You can buy new spindles, for most of them. You mentioned pinch bolts, rules out Profile and their derivatives. Assuming it's not some off brand, and not one of these weird "two piece" cranks with the spindle pressed into the drive side arm, getting a new spindle should be a fairly simple matter. But, you need the spindle for the brand of cranks you have. They're not interchangeable.

Thanks, it is all fixed now.