Jackshaft Optimal Sprocket Size?

[The Speaker Guy]

Hi
Working on next quad sociable, and will use a jackshaft on passenger side to offset chainline for wider rear wheel base.

If the rear is a 7 speed derailleur, is there any limit to diameter to consider for the jackshaft sprockets?

Of course, upper limit is similar to front sprocket, but is there a lower limit? Smaller is better for size, and less torque on 12mm shaft, but I am worried about performance with rear derailleur.

Donor is Rad Mini, with a 48T chainring to an 11-34T 7 speed cluster.

Thanks in advance
John

 

[larsb]

Since you’re running a 7 speed cassette (?) the obvious smallest front sprocket will be a bike sized one 8)

Jokes aside.. It’s not good to go lower than 12-13t as chain tension gets high and extra chain wear and noise will be caused by the chain polygon effect (google it)

 

[The Speaker Guy]

Thanks, that makes sense. I think I will use 20t which will allow me to grip in 4 jaw chuck to trim the center to a weld adapter.