How profitable of a business do you think restoring and modifying motorycles would be?

Nope, not working

Follow up thought - if you do decide to do it, you have to find the least amount of things to do to get it running and turn it. If you want to do a $2300 custom build with a stretch and cafe conversion, led kit and new exhaust you will never get your money back. - I have watched these sit on craigslist for months.We are all talking if you want to do it for cash, wash it, run it, repair the torn seat and sell it.

I've rebuilt and sold quite a few classic bikes. It isn't a great business.go to work for another bike shop, learn the skills, learn the pitfalls, and expensive and unobtainable parts list. You cannot recover your time in dollars. Write a business plan, and discover the cost of an inventory.

Over the past few years I've bought, fixed, rode, and then sold 15 bikes that would fall into the category your describing. I usually try to get them clean and roadworthy, rather than truly custom bikes. I consider this a hobby, not a business.

Given that, my thoughts are:

On some bikes I make money, some lose, some break even. The most I've "made" is ~$1000 on a BMW the seller sold cheap based on bad info from a shop that was trying to sell him a new bike. Most of the time I clear ~$300.

To really make this a business, I would need more storage room, a trailer/truck for hauling new inventory, a tire changing tool, and maybe a basic paint shop. If you can't paint, then farming out the paint will eat up profit. Same for changing tires, but to a lesser extent.

I would also need a flexible "real" job that I could leave at a moment's notice to go buy wicked good deals before someone else snapped them up. Or I would need to be retired.

Before calling it a business, try it on 3-4 bikes. Keep track of what you spend and what you clear, and then decide if a business is feasible.

Your location will matter. You'll need to be close to a city to have a large enough pool of potential buyers. I see bikes on CL or FB that would sell quickly if they were closer to a city, but don't sell because they are out in the sticks.

Also, consider that potential buyers are going to evaluate you when making a purchase decision. Aside from your age, what does your house/shop look like? I looked at one bike that was being stored and disassembled outside under a open sided tent on a peninsula about 50 yards from a salt water. There's no way I was buying that bike.

I knew I guy that did something like this but with classic. He would buy, frame up restore, and then sell. He did all the work himself in his own shop, body, paint, and wrenching.

However he didn't do it full time. I asked him why and he said "I love restoring cars. I don't want my lively hood to he dependent on my passion. It wouldn't be the same" It was essentially a hobby that would make a small profit.

I don't know what you can do with that info but there it is.