first of all, having 100% exact match anchors is recipe for disaster (your page will never rank with spammed anchor texts). So, only use "car hub", "bike hub", or "car and bike hub" 5% or less of the time (which means only once if you're going to have exactly 20 backlinks)
secondly, if you have content that targets both cars and bikes I would say (unless I have more information about your site, niche, etc) that it's a bad idea targeting 2 different keywords with the same piece of content. Content that targets totally different keywords almost never ranks well, and for such content it practically won't matter which anchors you use because - like I said - you'll almost never rank well. You might still rank, but like I said, you might not rank as well as you should. Better that you talk in one article about car hubs, and in another article about bike hubs, whatever these are...
Now, if the page you're trying to rank is a services type of page (like, car / bike rental) then targeting these 2 keywords on the same page might work (that's why I mentioned that I don't have enough info about your site, niche, etc). But even so, even if this was a services page, using the same anchor text 100% of the time is still a bad idea.
What I recommend is 1) split the content into 2 different topics (car hubs and bike hubs) so you can better optimize each piece of content for its main keyword, and 2) after you make the split use exact match anchors (car hub / bike hub) for less than 5% of your backlinks (and preferably in your best links that are d0foll0w), with the other 95% of the backlinks using generic (visit us, click here, on our site, on our blog, according to this article, etc... just use your creativity), branded, or naked URL anchors
