One technical question

I think here's need external chain tensioner to save and long life of gear hub

Quoted post said:

Originally Posted by GREEN Composite [IMG]/img/forum/go_quote.gif[/IMG]

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.

You can use a chain tensioner if you want to have a double crank on front. I dont see any other reason to use it unless there is a performance issue?

Most of the frames I seen which are built for internal geared hubs do not have provisions for a chain tensioner (or deraileur).

As far for the dropouts maybe it doesnt matter how they are arranged as long as the chain tension remains correct? (better friction arrangments on the quick - release or bolts - bolt contact surfaces?)

Quoted post said:

Originally Posted by Volnix [IMG]/img/forum/go_quote.gif[/IMG]

As far for the dropouts maybe it doesnt matter how they are arranged as long as the chain tension remains correct? (better friction arrangments on the quick - release or bolts - bolt contact surfaces?)

If you have vertical dropouts, getting the correct chain tension usually means mucking about with half-links and suffering limitations in which chain wheels/sprockets you can use. Not impossible, but a bit tedious. Horizontal dropouts or chain tensioners make it ever so much easier.

FWIW. There are CHAIN TENSIONERS which simply attach to the chainstay ...

• Basically, they are comprised of a single pulley wheel which is attached to a bracket which you then move forward-or-backward along the stay to adjust the chain's tension.