# Rear derailleur to chain tensioner conversion



## eithr (Jun 27, 2007)

Does anyone have a fun, fancy, creative way to convert a rear derailleur into a chain tensioner?


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## FatTireFred (Jan 31, 2005)

adjust the limit screws?
...and perhaps some stickers or paint


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## Dave Hickey (Jan 27, 2002)

It depends on your chainline. You can try adjusting your limit screws to set the derailleur in the proper position. If not, you need to have a cable and shifter to get it in the proper place. The key is getting the proper sideways position to line up with the cog and chainring. The actual tension takes care of itself by threaded the chain through the pulleys just like a geared bike.

That being said, you can get a chain tensioner for less than $20 on eBay. Performance sells a complete single speed kit for $30.00. It includes all the spacers and tensioner.


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## PeanutButterBreath (Dec 4, 2005)

Dave Hickey said:


> It depends on your chainline. You can try adjusting your limit screws to set the derailleur in the proper position. If not, you need to have a cable and shifter to get it in the proper place. The key is getting the proper sideways position to line up with the cog and chainring. The actual tension takes care of itself by threaded the chain through the pulleys just like a geared bike.


No need for a shifter. You can seat the head of the cable in the RD's barrel adjuster, position the RD by hand and anchor the other end as per ususal. Done this way, the barrel adjuster can be used to fine-tune positioning.


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## 24601 (Jul 4, 2005)

I've done it using a cable backward in the barrel adjuster. It worked, but it was almost impossible to get the wheel out. I loosened it (added a link) to give me more room to get the wheel out, but then I got chain slap and a popping when climbing. Of course, all this was on a mountain bike, so...










Of course, then I found a magic gear (perfect tension, no tensioner) and all was bliss.


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## PeanutButterBreath (Dec 4, 2005)

I've done it with an XT RD and a MTB triple chainring on a CX bike. No issues with the chain popping. Wheel removal was no harder than with a Singleator. Chainslap is a fact of life with RDs.


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