# Recommendations for a chain tensioner



## Jenkins (10 Feb 2017)

I have an old Boardman road bike which I converted to single speed at the great cost of £8.95 for a Planet X kit and using an old dérailleur as a chain tensioner as an experiment. Having decided to keep the bike in this mode permanently, the dérailleur looks ungainly and I'm expecting my bodge to lock it into a position that gets an acceptable chain line will fail so I'm looking for something neater. The best option seems to be something like the On-One Doofer, but can anyone suggest something similar or better or (preferably) cheaper as I want this to be a real budget job?


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## S-Express (10 Feb 2017)

Brick Lane sells the same/similar item for £18, but it's not like £19.99 is a lot of money either way.


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## Jenkins (10 Feb 2017)

S-Express said:


> Brick Lane sells the same/similar item for £18, but it's not like £19.99 is a lot of money either way.


Yes I know, but I'm a tight arse when it come to this sort of thing


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## S-Express (10 Feb 2017)

Try ebay - there's loads.


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## Racing roadkill (11 Feb 2017)

Jenkins said:


> I have an old Boardman road bike which I converted to single speed at the great cost of £8.95 for a Planet X kit and using an old dérailleur as a chain tensioner as an experiment. Having decided to keep the bike in this mode permanently, the dérailleur looks ungainly and I'm expecting my bodge to lock it into a position that gets an acceptable chain line will fail so I'm looking for something neater. The best option seems to be something like the On-One Doofer, but can anyone suggest something similar or better or (preferably) cheaper as I want this to be a real budget job?



One of the problems with converting a stock, derailleur geared road bike, to a single speed set up, is the fact that the rear dropout is typically vertical, rather than the more traditional horizontal, found on a fixie / SS. It's a bit of a pain, but as you've no doubt found out, there are ways around the problem.


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## simongt (12 Feb 2017)

I had a Surley Singleator put on my GT Outpost when I converted to a SA 5 speed about ten years ago. So far no issues.  More recently, when my GT Bravado was converted to a SA 8 speed, I simply kept the rear derailleur hanger in place and it's been fine. As long as it's lined up with the chain run and the pivot points are kept lubed, shouldn't be an issue.


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## bonsaibilly (12 Feb 2017)

Why don't you just get a single speed chain? They only cost a fiver. 

I'm assuming the planet x kit you bought was the same thing I did, which is a cog plus a bunch of spacers for your freehub.


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## S-Express (12 Feb 2017)

bonsaibilly said:


> Why don't you just get a single speed chain? They only cost a fiver.



How is getting a new chain going to help?


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## bonsaibilly (12 Feb 2017)

S-Express said:


> How is getting a new chain going to help?



Surely it would obviate the need for a chain tensioner? 

Maybe I'm missing something.


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## S-Express (12 Feb 2017)

bonsaibilly said:


> Surely it would obviate the need for a chain tensioner?



It wouldn't. Why do you think that?


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## bonsaibilly (12 Feb 2017)

S-Express said:


> It wouldn't. Why do you think that?



I don't know. How does a chain tensioner work? I didn't use anything like that, just a single speed chain with some links removed. 

I would have thought that a single speed conversion would look best if one removed all the mech bits and put a single speed chain around a single speed cog.


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## midlife (12 Feb 2017)

Takes the slack out if the chain for single speed bikes with dropouts that don't allow the wheel to be pulled back..

Shaun


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## bonsaibilly (12 Feb 2017)

Okay thanks that's the technical explanation I needed. Still and all, can't one just remove links to fit?


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## S-Express (12 Feb 2017)

bonsaibilly said:


> I don't know. How does a chain tensioner work? I didn't use anything like that, just a single speed chain with some links removed.



Not sure what you mean by a 'single speed' chain. Chains are generally either 3/32 or 1/8 pitch, single speed or not.



bonsaibilly said:


> I would have thought that a single speed conversion would look best if one removed all the mech bits and put a single speed chain around a single speed cog.



The bike would need track ends, not vertical dropouts, in order to be able to do that.


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## S-Express (12 Feb 2017)

bonsaibilly said:


> Okay thanks that's the technical explanation I needed. Still and all, can't one just remove links to fit?



No, because you would still have no means of micro adjustment, because the bike does not have track ends. Which is why you need a tensioner.


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## midlife (12 Feb 2017)

Tricky, sods law says using half links is that the chain is just very slightly slack or too tight to fit in the dropout

There's always an eccentric bottom bracket 

Shaun


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## Elybazza61 (12 Feb 2017)

Hello Jenkins,started a conversation with you.


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## bonsaibilly (12 Feb 2017)

S-Express said:


> Not sure what you mean by a 'single speed' chain. Chains are generally either 3/32 or 1/8 pitch, single speed or not.
> 
> 
> 
> The bike would need track ends, not vertical dropouts, in order to be able to do that.



First off I set out to Google "single speed chain" but then I realised you and I both know already that such products exist. I've no idea what makes them vastly different to multispeed chains.


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## S-Express (12 Feb 2017)

bonsaibilly said:


> First off I set out to Google "single speed chain" but then I realised you and I both know already that such products exist. I've no idea what makes them vastly different to multispeed chains.



Your google results are probably returning 1/8 chains, which is the traditional single speed width. The OP is almost certainly still on 3/32, which is the standard width for multi-speed chains. So fitting a single speed chain, while technically possible, is not going to solve anything.


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## midlife (12 Feb 2017)

A slight digression.....I'm just about old enough to remember 1" pitch chains and the chanrings that went with them....







And just about young enough to remember the 10mm Shimano jobbies.





Shaun


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## S-Express (12 Feb 2017)

midlife said:


> And just about young enough to remember the 10mm Shimano jobbies.



Proof that not even Shimano can alter a global standard that doesn't want to be altered...


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## midlife (12 Feb 2017)

S-Express said:


> Proof that not even Shimano can alter a global standard that doesn't want to be altered...



I guess you remember their failed attempt at a new standard for brazed on gear bosses to LOL

Shaun


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## Jenkins (12 Feb 2017)

Thanks to all and just to confirm, I am running a converted 10 speed freehub with a Planet X conversion kit (spacers and a cog) on a bike that runs vertical dropouts with no means of horizontal adjustment to keep the chain (3/32nds and a spare 10 speed I had lying around) tensioned, hence the need for something like the Doofer to take the place of the rear dérailleur using the same mounting.

@Elybazza61 - I'll send a reply shortly - thanks


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