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Discussion Starter · #1 ·
I have a KHS Solo one Se that has different chain tensions depending on where you are in the crank revolution. It is tight at 12 o'clock(pedal at top) but very loose at 3 o'clock. It looks like the chainring is oblong if that makes since. Is this normal?

Thanks,
Brian
 

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Ye Olde Phartt
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I've had that issue on every bike I've ever owned to some degree. My Surly Singleator tensioner takes care of it though and works great on my KHS DJ300.

I would assume that there are better machined and/or stronger chainrings out there that would minimize or eliminate this. Or maybe bashing the chainring into obstacles causes them to get out of round. Is this a new setup?
 

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Out spokin'
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There's a degree of out-of-roundness to every drivetrain component, some more than others. Don't rule the crank's spider out, either.

If most of it comes from your chainring, there's a technique that may help. Find the place where the chain is tightest. Loosen the chainring bolts, but not all the way. You want a little friction left there, but you want the ring to be able to move when you apply enough force. Once you've loosened the bolts, squeeze the chain's top & bottom run together. This may "center" the chainring by pulling it to a place where it's more concentric with the bottom bracket spindle. Then tighten the chainring bolts.

Sometimes this helps, sometimes not.

--Sparty
 

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Discussion Starter · #4 ·
It is new. It is a very cheap crank and wonder if a "better" crank would help or if it's just the chainring. I have asked a few people that own this bike and they notice it also. I just wondered if it was just the crank or is the bike. The crank is a Truvativ Blaze. Thanks Ken for your reply.

Brian
 

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max_29
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blooper said:
It is new. It is a very cheap crank and wonder if a "better" crank would help or if it's just the chainring. I have asked a few people that own this bike and they notice it also. I just wondered if it was just the crank or is the bike. The crank is a Truvativ Blaze. Thanks Ken for your reply.

Brian
i have a Truvativ Blaze crank and don't have the issue you described. that crank may be cheap, but that does not mean it's poorly made... just a realistic price :)

you'll need to play with a chainring centering, like suggested above.

FWIW, i just installed a ring ordered from ISAR (Dan) - a perfect "circle" fit.

does you chainring has a lot of play on a spider when not fully tightened?
 

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Are we there yet?
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Sparticus said:
There's a degree of out-of-roundness to every drivetrain component, some more than others. Don't rule the crank's spider out, either.

If most of it comes from your chainring, there's a technique that may help. Find the place where the chain is tightest. Loosen the chainring bolts, but not all the way. You want a little friction left there, but you want the ring to be able to move when you apply enough force. Once you've loosened the bolts, squeeze the chain's top & bottom run together. This may "center" the chainring by pulling it to a place where it's more concentric with the bottom bracket spindle. Then tighten the chainring bolts.

Sometimes this helps, sometimes not.

--Sparty
Right. Sometimes re-installing the ring in a new position in addition to the above technique will help center it too.
 

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It normal and if you've moved the position of your chainring make sure you put it back with the indexing mark(bump or notch on the inside of the ring) behind the crank arm because it's done to compensate for your power stroke. I have my girlfriend to thank for learning about this "my chain is too loose"
 

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chrispanosc said:
It normal and if you've moved the position of your chainring make sure you put it back with the indexing mark(bump or notch on the inside of the ring) behind the crank arm because it's done to compensate for your power stroke. I have my girlfriend to thank for learning about this "my chain is too loose"
But this only applies to chainrings with shifting pins and ramps, and as this is the Singlespeed forum..........:eek:

Other than centering issues, it makes no difference how you position a SS chainring (well, unless it's Biopace or Egg, I suppose :rolleyes: ).
 

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Andy R said:
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Other than centering issues, it makes no difference how you position a SS chainring (well, unless it's Biopace or Egg, I suppose :rolleyes: ).
This is true if the parts in question are %100 percent true in all respects. As mentioned earlier, all parts have some variance. If they didn't this chain tension issue wouldn't exsist.

In some cases it will indeed be easier to get closer to even results after trying the ring in a different position.
 

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AlmostQuick said:
This is true if the parts in question are %100 percent true in all respects. As mentioned earlier, all parts have some variance. If they didn't this chain tension issue wouldn't exsist.

In some cases it will indeed be easier to get closer to even results after trying the ring in a different position.
Which is why I said "other than centering issues" ....;)
 

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Andy R said:
But this only applies to chainrings with shifting pins and ramps, and as this is the Singlespeed forum..........:eek:

Other than centering issues, it makes no difference how you position a SS chainring (well, unless it's Biopace or Egg, I suppose :rolleyes: ).
Thanks for letting me know what forum it was:thumbsup:
I was talking about a singlespeed specific crank and chainring on a singlespeed bike.
 
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