This is a beautiful part that I would like to dedicate an article on its own. K6-III at Bike Forums came up with it. Thanks! I have been evaluating some DMR chain devices and some others for use with my Alfine internal gear hub, but did not really find what I was searching for. I would like to get rid of the heavy Alfine chain tensioner (see image at right side) due to several reasons. Unlike the DMR and other tensioners mounted at bottom bracket, the Kore tensioner uses a cantilever spring to maintain chain tension and therefore, once installed, does not need to be adjusted manually. Here are some reasons for replacing chain tensioner mounted at derailleur hanger:

• weight
• need to completely remove Alfine chain tensioner for rear wheel deinstallation, making it a pain since it stays losely connected to chain running through the pulleys. Reinstallation of tensioner is kind of cumbersome.
• why routing chain through these small pulleys in tight bends just to keep some tension on it?
• less cleaning effort

I may probably give it a try. Benefits would be shorter chain length (weight), no more pulleys, nothing that could deform derailleur hanger when being hit accidentially, wheel removal much easier. On the other hand, it might cause some noise when being operated. However, since it needs to be mounted at rearmost part of chainstay due to special Big Dummy frame, not fulfilling Kore mounting instructions, I doubt there is enough vertical chain clearance that could be used up to create tension at chain, so this purchase would be kind of risky in terms of cost. I will need to ask for price at first. Anyway, after doing some research it looks like this item is not easily available over here.

Björns blog article describes a new and interesting Big Dummy build up project starting right now. His 20″ frame was announced to arrive today. His assembly kit includes heavy duty sports components as like Magura Gustav M downhill brakes in combination with Shimano Alfine internal hub and hub dynamo for allround and offroad usage. I am really curious how it will work. Check his complete blog for any further information. Björn, have fun with it!