I think this bike forum is primarily an advertising thing with banners and the attraction is what's called "content" in the industry.

To get riders, one needs to identify them. I think that's the first step. The Baby Boomer age group are those born between 1957-1946. So there's your 50 +.

Once you get more people into this forum, your advertisers will get more hits.

I think content is one way and this is what you're asking. But try this in reverse. Consumers want a deal and these advertisers may not be the ones that give the best deals. Take a look at your banners and now take a look at the posts specifically targeted at consumer preferences. I think you have a gap to fill.