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Discussion Starter · #1 ·
I just recently converted my old bike to a single speed. I have a chain tensioner and used a cog from the disassembled cassette. The problem that I can't seem to fix/understand is that if I put a fair amount of pressure pedaling (uphill for example) the chain will skip on the cog. I thought it was a chain alignment issue but that doesn't seem to be it (as aligned as can be). My next step is to shorten the chain a bit in order to tighten the tensioner and get more conatct area between the chain and the cog.

Has anyone else had this issue and/or know what I am doing wrong?
 

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sometimes it can be the rear cog not having deep enough teeth to hold the chain. SSing means a lot more pressure on that cog and also is it an old chain (they can stretch).
 

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Birthday Collector
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Sounds like you used an older cog and/or chain? Most likely the chain is stretched (worn) or the cog is worn to an older chain, and the new chain is not seating properly. Once a chain has worn too much it is no longer 1/2" pitch and will need to make up the difference every so many links, which comes across as a "skip" as the bushing comes down on top of a tooth instead of in the "trough". Likewise, the worn cog can have problems matching with a new chain and the same sort of thing will happen. If both items are worn, I'd recommend getting 1/8" width chain and cog - they last a lot longer SS'ing!
 

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As the two previous posts - use the tensioner pushing up to get the maximum chain wrap, fit a new deep tooth singlespeed specific rear sprocket along with a new chain (I suggest KMC-Z610) and have the chain as short and as well aligned as possible.
Should do the trick I think. :thumbsup:
 

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Discussion Starter · #6 ·
Thanks for everyones reply.

The chain and cog have been paired together on the same bike since i bought it. The only thing i did was disassemble the cassette and shorten the chain. I suppose that could cause any of the issues that have been outlined.

My tensioner is one that pushes down - is there a recomendation for me as to one that pushes up?

I will get a new chain (and I have a SS cog in the house somewhere).

thanks again.
 

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I had the same issue when I first converted and found that after changing every thing (bottom bracket, chainring, crank arms, rear cog, chain) I was ever so slightly out of alignment. But does frame flex come into the equation? Sorry for going off on a tangent on you guys, but can that happen?
 

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Hoosier
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I had the same problem with my chain tensioner that pushed down. I took out an extra chain link and that fixed the problem.
 

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knock-knock...
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i had a similar problem once, but it turned out i had worn my (ramped) front chainring down to the point where it was the culprit.
 

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Frt Range, CO
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jbsmith said:
....I have a chain tensioner and used a cog from the disassembled cassette....Has anyone else had this issue and/or know what I am doing wrong?
Yes, I had the exact same problem when I used a used cog from a disassembled cassette. I switched to a single speed cog, problem went away.
 

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Retro Grouch
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jbsmith said:
I just recently converted my old bike to a single speed. I have a chain tensioner and used a cog from the disassembled cassette. The problem that I can't seem to fix/understand is that if I put a fair amount of pressure pedaling (uphill for example) the chain will skip on the cog. I thought it was a chain alignment issue but that doesn't seem to be it (as aligned as can be). My next step is to shorten the chain a bit in order to tighten the tensioner and get more conatct area between the chain and the cog.

Has anyone else had this issue and/or know what I am doing wrong?
As said above, first you need to get the basics right. Assuming your gears and chain are in reasonable condition, look to the tensioner. First, your chain needs to be as short as possible (think half link if necessary); most tensioners are not designed to adjust to a smaller or larger cog. Sometimes, you'll have everything right and still get a skip. That is because spring tensioners don't have much chain wrap in the push down position and unless you have a Surly, most the other spring tensioners don't have a push up mode. If you find yourself in that position, pull out the spring and use some zip ties to tension the tensioner arm to the chain stay; it will look like below. Good luck.
 

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