nick9826

Hi,

Let me preface this by saying I am relatively mechanically inclined, but know next to nothing about bikes.

I have recently purchased a 1985 Nishiki Continental equipped with a Suntour Cyclone M-II rear derailleur. It mostly works well, but there is a persistent noise while riding. I believe the derailleur has two lower jockey wheels (if this is the correct term). One of them doesn't appear to be doing anything except lightly rubbing the chain. I also don't see this second wheel on any other Suntour Cyclone M-II's pictured online. Can I just remove this? Or is it doing something important that I'm missing?

Any insight as to steps I can take to spruce up my derailleur, and what this second wheel is doing, would be greatly appreciated.

John Nolan 

This is a rare item. Read more about it here.
Don't remove that third wheel. It's probably not the source of the rubbing.
In all likelihood the drivetrain just needs to be set up correctly. Here's an overview.
Just in case you don't know—the system is friction, not indexed, so it's up the the rider to adjust their shifting to avoid rubbing.

clubman 

It's possible that either the derailleur hanger or the RD itself is bent. Typically the 3 pulley Suntour is an effective gear. Pics from the back of the drive train showing the chain line would help evaluate the issue..

Aardwolf

You can get the diagram at www.disraeligears.co.uk
There's also a GT version for bigger cogs.

Bianchigirll 

I assume you’ve taken the inner cage plate off and cleaned and lubed everything? Did you get everything back together in the correct order?

nick9826

Thanks for all the responses and for pointing me in the right direction, I've been learning lots!

I now realize that the third pulley wheel only contacts the chain when I'm in certain gears (which makes total sense now that I understand what's going on). I guess when I looked at it before it was in such a position that it was mostly raised above the chain, but just touching enough to make a little noise. The noise doesn't bother me as long as I know that everything is working correctly, so that's all good.

I think a good cleaning and lubing is in order, which is next on the list.

The Golden Boy 

Exactly- the 3rd pulley forms an "elbow" and can take up more slack in the chain without just having a longer "arm."

The small pulley is so that when the chain is taut, the pulley doesn't rub on the cogs as the arm/elbow gets pulled upwards- as I found out by replacing that pulley with a 10 or 11T sealed bearing pulley...