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[Closed] 2 chainrings on a singlespeed

 DezB
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[#1603692]

I'm sure I saw this on a Singular at Swinley.. is it fairly common practice?Presumably so you can manually change onto the bigger chainring for road use?


 
Posted : 13/05/2010 12:17 pm
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Usually, there's a second sprocket too. Provided the chainring+sprocket has the same number of teeth, most tensioning systems have enough adjustment to take up any minor slack.

So, 32:18 and 36:14 as a low/high gear.


 
Posted : 13/05/2010 12:23 pm
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I used to run 2 rings, as I did not want to spend £10 on some short bolts!


 
Posted : 13/05/2010 12:26 pm
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quick question though, i have a WI duo freehub, and deore HT2 cranks. if i have rings in the middle and big spaces (but 2 teeth different), will the spacing and chainline get mesed up?

thinking of running 32:19 and 34:17


 
Posted : 13/05/2010 12:26 pm
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meehaja +1 😉


 
Posted : 13/05/2010 12:29 pm
 DezB
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[i]Usually, there's a second sprocket too.[/i]

Ah - to keep the chainline, I guess..


 
Posted : 13/05/2010 12:31 pm
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Ah - to keep the chainline, I guess..

And to keep the chain length similar.


 
Posted : 13/05/2010 12:34 pm
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thinking of running 32:19 and 34:17

The change in chain angle means that it won't be taut.

Trust me I've done it!


 
Posted : 13/05/2010 12:51 pm
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figured as much, but i've sliding dropouts, but they don't quite slide enough to allow me to run the 2 gears, reliably, on the same chain length.

plus, 2t difference ain't a large amount!


 
Posted : 13/05/2010 12:55 pm
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Aye fair enough if you want to adjust the sliders. I stuck a chainring in to keep it tight but that was a PITA TBH TYVM.


 
Posted : 13/05/2010 12:57 pm
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errr. not really a singlespeed then is it?


 
Posted : 13/05/2010 12:58 pm
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you can get upto 10 sprockets now with a self tensioner thing....


 
Posted : 13/05/2010 12:58 pm
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no jam bo, its 2 speed.

HTH 🙂


 
Posted : 13/05/2010 12:59 pm
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Do you mean a dinglespeed?
http://www.psyclestore.com/pages/INSTRUCTIONS:-Dingle-Speed.html


 
Posted : 13/05/2010 12:59 pm
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you can get upto 10 sprockets now with a self tensioner thing....

uh huh. which i have, and guess what, you can even get 14 speeds INSIDE a hub!!!!! which i have also had.

🙂

2 speed though, doesn't have all that mess on your bars, doesn't get caught on anything and ripped off, and doesn't weigh a ton 😉


 
Posted : 13/05/2010 1:01 pm
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gearfreak, i currently have a DOS, want 2 on the front.

thanks for the link 🙂


 
Posted : 13/05/2010 1:03 pm
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I run a granny ring with a rohlhoff tensioner in addition to my 32:16 ratio, so whn I'm knackered at the end of the day, I can still ride hills without getting cramp. I call it my 'cheater gear' because that's what it is.

I don't use it at all locally though.


 
Posted : 13/05/2010 1:37 pm
 DezB
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jam bo - Member
errr. not really a singlespeed then is it?

Not that it matters, but yes, it is. You can't change gear when you're riding can you?


 
Posted : 13/05/2010 1:46 pm
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The change in chain angle means that it won't be taut.

Trust me I've done it!

So have i and its fine, infact i reckon a lot of people have or they probably wouldnt sell any.

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Posted : 13/05/2010 1:52 pm
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w/o adjusting the chainstay length?

Can work for some magic pairs of ratios I guess.


 
Posted : 13/05/2010 2:06 pm
 Olly
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Black magic and guessing!

i think it would only be worth it if you could get it to work in two ratios that used the same number of links (taking up slack is no real problem)


 
Posted : 13/05/2010 3:19 pm
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well i ran a 40-18 which according to a magic calculator is 16.909" and 42-16 is 16.873" for an assumed chainstay length of 17" , so not a massive difference. I never felt the need to take up any tension when i changed ratio, and id like to see someone who can set their tension that perfectly!

http://eehouse.org/fixin/formfmu.php

Rich


 
Posted : 13/05/2010 6:05 pm