As few breaking parts as possible and least possible service needed,we would use Shimano 8-speed internal hub gears (135 mm ODL), BUT without external chain tensioner. Would that be a problem for the frame sets (vertical drop outs needed)?
I guess the O.D.L is not a problem but perhaps our wish NOT to use external chain tensioner.
I guess the O.D.L is not a problem but perhaps our wish NOT to use external chain tensioner.