# Singlespeed & Fixed Gear - If 46x18 works without tensioner what else will?

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MtbVA
06-08-08, 06:16 PM
If a 46 front & 18 rear works without a tensioner how many teeth at a time can I drop and still not need a tensioner?
I guess I'm looking for a relationship between cog teeth & links.....such as X teeth = Y links.
I'm converting a Klein Pulse MTB to single speed for commuter use and the 46 tooth front (stock shimano triple cranks with 26-36-46) with a conversion kit using 18 tooth rear cog has perfect chain tension, but I'd like to drop a few teeth to make it a little easier to pedal for everyday use.

bdfresh
06-08-08, 06:23 PM
im not sure but its interesting. I have a Scattante XRL single speed that had a tensioner on it but now doesn't, its perfect tension too, and i am kinda (but in not at all) wondering what else would work as well. IM sure it correlates to some many gears=so many links bla bla bla

helloamerican
06-08-08, 07:39 PM
you's gonna get jello legs riding an easier ratio than that.

mtnbiker4791
06-08-08, 09:22 PM

06-09-08, 03:42 AM
Maybe my stoned logic is faulty, but wouldn't any ratio with the same number of teeth work? If you have the same total number of teeth in two ratios, wouldn't that mean the same number of chain links are engaged at all times? Would that not mean that the chain lengths would be the same?

For example:
46x18=64 teeth
45x19=64 teeth
47x17=64 teeth
etc.

Is this correct?

ryansexton
06-09-08, 06:45 AM
Nope. 1 tooth in your rear cog is worth 3 in the front, or at least thats what I was explained.

The teeth might be the same, but the gear inches would be off.

Aeroplane
06-09-08, 07:21 AM
Maybe my stoned logic is faulty, but wouldn't any ratio with the same number of teeth work? If you have the same total number of teeth in two ratios, wouldn't that mean the same number of chain links are engaged at all times? Would that not mean that the chain lengths would be the same?

For example:
46x18=64 teeth
45x19=64 teeth
47x17=64 teeth
etc.

Is this correct?
This is the rule of thumb. Of course, there will be a little bit of variance due to the angles at which the chain comes off the chainring/cog, but it's the best thing you can do without doing some mad trigonometry.

06-09-08, 01:49 PM
Nope. 1 tooth in your rear cog is worth 3 in the front, or at least thats what I was explained.

The teeth might be the same, but the gear inches would be off.

Well, of course. We're talking about changing ratios without having to move the wheel. Being able to have ratios with different gear inches is the goal here.

Cynikal
06-09-08, 02:26 PM