# DIY chain tensioner!



## mafia6 (Sep 30, 2005)

really proud of it! Cheap, Light and it works! if i smash it i just have to make another one. Made it as i was fed up of my chain stretching.:madman:

made from bent mild steel, steel bolts, nuts and spacers with a spare kcnc jockey wheel. 69grams on my lbs weighing scale. :thumbsup:


















thinking of making a one more improved one...anyone has any suggestions? i was thinking of filing the mild steel down even more to have a more attractive design instead of drilling holes.


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## fishcreek (Apr 10, 2007)

i still remember one member here posted a home-made tensioner out of small wrench and i think it is so cool. cant beat the strength of a forged steel too.


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## McGyver29er (Oct 3, 2006)

*Very nice design.*

Very nice!
Looks pretty cool.
I like the fact it is on the QR so you can easily adjust it.

I did the wrench with only bike parts from the junk box. Except for the bolt through the jockey wheel.








1 3/8" combination wrench
1 chain ring bolt through the box end of the wrench
1 4mm bolt 3/4" long- through the bushing on the jockey wheel & the chain bolt
1 QR seat post clamp nut(from inside the lever)
1 deraileur hanger bolt and bushing from inside the body of the deraileur

I was thinking of putting a zip tie around the chainstay and the tensioner to prevent it from loosening.

I once took a spoke and bent it in a fashion to add tension up on the norailer I bought for another bike. Before I saw the thread about DIY tensioners.
Hooked it on the fender bolt hole. Took the jockey wheel off and spun the tensioner clock wize then reinstalled the jockey wheel. Hooked the spoke around it.








The all time best tensioner I saw was the spoon. Classic DIY

I was just wondering what you use this ride for. I find it hard to ride with platforms since I went clipless.

Great job.


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## mafia6 (Sep 30, 2005)

McGyver29er said:


> I was just wondering what you use this ride for. I find it hard to ride with platforms since I went clipless.
> 
> Great job.


oh i use this bike for urban riding and some hardpack trails. I tried a local rocky/gravel trail but had a terrible time trying to keep my foot on the platforms during the downhills. especially since i am using a rigid fork. I came from clipless and i am never going back..a big part due to the convenience of being able to just use any shoe and its easier to bail when i huck stairs or kerbs and when something goes wrong. :crazy:

but for pure speed clipless is still better though...but i am lazy to ride fast. lol


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## toyota200x (Sep 9, 2005)

I love home made parts, especially chain tensioners. Here is one I made in 1/2 hour and it works great.


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## fishcreek (Apr 10, 2007)

nice DIY's, can anyone tell me what exactly is the size of a derailleur hanger bolt? i mean the thread, thanks.

edited: 
found it, M10


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## ernesto_from_Wisconsin (Jan 12, 2004)

I remember seeing one that someone made with a spoon.


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## eccentricbottombracket (Nov 13, 2006)

How do you adjust it for chainline, with washers or pliers?


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## mafia6 (Sep 30, 2005)

eccentricbottombracket said:


> How do you adjust it for chainline, with washers or pliers?


washers to adjust chainline...pliers if the tensioner becomes crooked or starts twisting..so far no problems.


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## fishcreek (Apr 10, 2007)

*here's mine*

used to be magic, but i thought it will be safer with my DIY.


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## smonroe100 (Mar 23, 2007)

Funny, I just made a tensioner out of some trash because I was frustrated with magic gears and it works so much better than it should for a piece of trash. 

I was wondering where some of you found those socket head allen bolts in the right size. I have checked several hardware stores as well as the internet and I can't find anything. It is an odd size with that 1.00 pitch. Any Suggestions

I'll Post pictures of my creation when I get the chance


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## fishcreek (Apr 10, 2007)

I was wrong about the M10 size bolt, or maybe I just picked up the wrong size. I end up using a smaller bolt with a nut and washer at the back so I can tighten it good.


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## smonroe100 (Mar 23, 2007)

fishcreek said:


> I was wrong about the M10 size bolt, or maybe I just picked up the wrong size. I end up using a smaller bolt with a nut and washer at the back so I can tighten it good.


It is an M10 Diameter but it has a really fine pitch/threading (1.00). I have only been able to find that diameter and pitch with a hex head, but I really wanted an allen head but I can't find one that fine.


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## ScaryJerry (Jan 12, 2004)

Take an old derailer and bust up the main pivot to harvest the delicious honey out of the hive. Or you could just get the main mounting bolt out of it and use that as the basis for your tensioner. Don't forget the zip-ties!


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## mack_turtle (Jan 6, 2009)

sorry, old thread. I am trying to make a DIY tensioner for a beater bike right now. any new ideas?

and if i can't make a diy tensioner work, has anyone tried this? http://www.slanecycles.com/shimano-...silver-p-11049.html?currency=USD&delivery=223

i had a Surly Singleator once and the spring blew up after just a few rides.


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## hatake (Jul 16, 2004)

First time I saw CT-S510. It's a fixed position (compared to spring loaded CT-S500), hangs onto the wheel axle (looks like it has a flat side). So you'll probably have to round the hole for your QR. If you do that, I'm not sure if it'll stay fixed on QR instead of the hanger - I'd bet not. So it may not be an ideal set up if you ask me...


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## aka brad (Dec 24, 2003)

The spoon


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## mitzikatzi (Sep 9, 2008)

More here


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## hoolie (Sep 17, 2010)

*Sweet Spoon*

I keep one in center console of my truck for lunch emergency. Little did I know I could walk back to truck, install spoon repair, and keep riding my bike.


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## sasquatch rides a SS (Dec 27, 2010)

I just made this today out of a backplate of an old derailleur and one of its jockey wheels.


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## jackspade (Jul 23, 2010)

I prefer the roller type than the pulley one.

I use pulley it's noisy and easy to derailed.


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## sasquatch rides a SS (Dec 27, 2010)

jackspade said:


> I prefer the roller type than the pulley one.
> 
> I use pulley it's noisy and easy to derailed.


I make sure to grease the spindle and bushing area of the jockey wheel every now and then and it's actually quieter than the STS tensioners that I've used and seen in the past. I'm not saying that goes for all, but in my experience I've always had more noise out of rollers. I always thought that it was because the shape of the chain never really ran smoothly on the flat surface of the roller, it would make alot of noise as it bumped across it with each link, whereas the jockey wheel is cut out to each roller on the chain so it kind of fits the form of the chain. I'm not sure if that made any sense..that's the best I can put it in words. And as far as derailling I've never had a single issues with either kind of tensioner whether it be spring, fixed, roller, or wheel.


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## mitzikatzi (Sep 9, 2008)




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## cdn-dave (Jan 6, 2007)

you da man!


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