Chain drive design, long length

[fusername]

So I have a chain driven system on a tricycle that I am kind of stuck with. the center distance of the two sprockets is 65 inches, and the chain is a 530 series, which has a pitch of 5/8. Now I have seen some sources reference or mention a 60 to 80 maximum of center distance to pitch ratio. My current ratio is 104. Now my question is why is that limit in place. I currently am using a single tenionser near the rear sprocket as it is the most conveneint location to mount a tensioner, but it is very clear I will need a second tensioner at the front. I am wondering if the 60-80 rule is simply to avoid the need for a tensioner or two, or if there is something more fundamental I am missing. Any good references on chain design would be excellent, the book I have is kind of skimpy on design considerations and just has a bunch of wear equations.

Thank you, also is this the right subforum for this?

 

[Averagesupernova]

I've never heard of that. When the center to center distance gets too great some kind of guide or rail may be needed. I see no reason to change the pitch though.