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Turning a 52-46-34 triple crankset into a 46-34 compact double

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Turning a 52-46-34 triple crankset into a 46-34 compact double

Old 06-09-11, 08:36 PM
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Turning a 52-46-34 triple crankset into a 46-34 compact double

I have a triple crank with 52-46-34 rings and really don't need all of the redunancy. I'm assuming that I could just remove the 52 and leave the 46 on the inside. But would it also work with the 46 on the outside of the crank?

Thanks
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Old 06-10-11, 05:17 AM
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Yes, that could work. I just turned a 118 BCD Sakae Custom that was originaly set up as a 52-47-36 triple (inner ring had been mounted on spacers on the same set of bolts as the outer and middle rings) into a 47-36 double. It works fine. I assume yours is set up the same way. If the small ring is on a smaller BCD than the outer rings, though, you're out of luck.
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Old 06-10-11, 07:46 AM
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Originally Posted by RFC
I have a triple crank with 52-46-34 rings and really don't need all of the redunancy. I'm assuming that I could just remove the 52 and leave the 46 on the inside. But would it also work with the 46 on the outside of the crank?
Hard to say, without a photo; there are cranks where this would work, and also cranks where it would not. If all three rings are attached with the same bolts, which are extra-long ones and have a single spacer between the 46 and 34 rings, then it's simply a matter of getting shorter bolts (readily available, ca $10). Put the crank together with the 46 and 34 where the 52 and 46 had been, respectively.

If you have one of the cranks where the two larger rings are configured as a normal double arrangement, and the granny is attached with another five bolts holes tapped into the spider, then doing what you suggest is more complicated and less elegant.
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Old 06-10-11, 07:56 AM
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I've been thinking about doing the same thing as of late.

34t is the smallest ring you can use on a 110 BCD crank, so it's possible this crankset uses only one mounting point. Many triples, though, use 110 BCD for the outer two rings and 74 BCD for the granny. Rudi is right, we need a pic

If it was the latter, I'd actually keep the 46t where it is, replace the 34t with a 30t and perhaps put a bash guard or the like in place of the 52t.
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Old 06-10-11, 08:11 AM
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I agree with Justin; I've had two bikes now set up with 74/110 BCD triple cranks as doubles. If that's the kind you have, I encourage you to shed the 52T gear and get a really tiny granny ring. It can look a bit funny, but if you like to spin it's awesome.

If you intend to use the 46T ring most of the time, having it in the "middle" position on a triple crank lines it up directly with the middle of your freewheel. (Assuming the correct BB spindle length, of course) That improves your average chainline across the whole freewheel.
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Old 06-10-11, 02:12 PM
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A lot of (maybe all of) the "middle" rings of a 110/74 double-plus-granny set have chainring bolt recesses on the inner side, and also a tapered ramp next to the teeth (often scarred up from chain traverses). Your choice with those is to mount the middle ring on the outside without flipping it (in which case the chainring bolts are on the "wrong side" of the recesses", or to flip the ring and be looking at the "inside."
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Old 06-11-11, 10:07 AM
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Originally Posted by jonwvara
Yes, that could work. I just turned a 118 BCD Sakae Custom that was originaly set up as a 52-47-36 triple (inner ring had been mounted on spacers on the same set of bolts as the outer and middle rings) into a 47-36 double. It works fine. I assume yours is set up the same way. If the small ring is on a smaller BCD than the outer rings, though, you're out of luck.
Hey, I'd be interested in those longer triple bolts if you want to get rid of them!
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Old 06-11-11, 10:10 AM
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Originally Posted by Charles Wahl
Your choice with those is to mount the middle ring on the outside without flipping it (in which case the chainring bolts are on the "wrong side" of the recesses", or to flip the ring and be looking at the "inside."
I've never had any trouble with simply removing the large chainring and using singlespeed chainring bolts, keeping the "middle" (now large) chainring in the "middle" position.

Why the complication? Have I just gotten lucky doing something most people have chain-dropping issues with?
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