...a bike accessory shop....
Our product line will be Trailers, Chrome , lighting , maintenance items, and some clothing. We will do no motor work oil changes or general mechanic work, just install what we sell .
I highlighted the statement about the proposed product line and what labor you would provide because it sounds like you are closely paralleling the history of a local shop. I'll try to be brief in the hope that you may find it useful.
Two guys down here, both very experienced (one a former long term employee of Arlen Ness and the other an associate of Dave Perewitz) wanted to do exactly what you describe. They were both at least semi-retired but wanted to stay in the atmosphere. Sell some chrome, filters, oil, maybe some clothes. Books and magazines. And hang out with the local riders. They didn't want to turn wrenches. They quickly discovered though, that their customers wanted them to install the chrome they sold, and then do the oil changes and mechanical accessories installation as well--stuff like Ness Big Suckers and pipes. They started doing this themselves but soon they needed help. Meanwhile, their customers wanted more complicated work--engine work, cams, heads, pistons, electrical, you get the picture. "Could you guys order this cam/ignition/carb/big bore kit/ whatever and install it?" That sort of thing. So they hired a Harley certified Tech from one of the local dealerships. All was well for a while. They even took in used bikes for sale on consignment and had a website for online sales and news.
Last year, though, the bottom dropped out of the market down here, anyway. Or maybe their customer base finally bought everything they wanted. They hardly ever sold anything but consumables involved in maintenance work (gaskets, spark plugs, oil and filters). The accessories from two years ago were still hanging on the walls and in the display cases. They sold the shop to a guy who downsized it to concentrate only on service, which was 90% of th business anyway. He moved out of half the storefront and devoted most of the space left to service bays. The new guy is OK and the good Tech is still there, but the "social" aspect is gone with all the lost floor space. It's only about 3 feet from the front door to the counter.
Bottom line of my story is that the owners opened the shop wanting to do the same thing you describe, but found themselves nearly forced to concentrate on service in order to sell anything, and not much sales at that. Then the motorcycle fad sort of died down and their business dropped off to a smaller, albeit steady level. Just not enough to keep it worth the effort to them.
When it was at its best, there was an ample front room with stools at the counter, free coffee most days and doughnuts on Saturdays. They had a TV/DVD player showing something all the time. Either re-runs of biker build off episodes, or maybe the movie "Easy Rider". Since one of them regularly traveled with Ness to the major rallies, there was always a stack of photographs from the most recent trip on the counter to sift through while you shot the breeze. They sponsored a Bike Night on Thursdays at one of two local locations for publicity and appeared on bikes with the Tech driving a truck towing the shop's logo trailer in the local community's July 4th parade. I really miss seeing them and the others at the shop. There was always a group passing through on Saturdays when folks were out riding. I miss it really bad, but I still run into the main former owner once in a while since he lives close to me. The other guy lives south of here--haven't seen him since. Bummer.
[edit to add] I should also state that this shop was open for about 5 years under the original owners. That's to give you an idea of the time involved in the events I outlined. They sold it last Summer and it's still going well, just service only.
I know this is long but maybe you can benefit from their experiences as they related them to me. I love the idea, myself. Good luck.