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Old 02-17-10 | 11:16 AM
  #23  
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Chris_W
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Joined: May 2007
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From: Switzerland

Bikes: road+, gravel, commuter/tourer, tandem, e-cargo, folder

The better approach to get lower gearing is to use a smaller chainring and not to use a wider-range cassette. I'm amazed that a company like SRAM cannot see the logic behind this argument and instead go in completely the opposite direction.

I agree that a triple is not necessary. In fact, I run a "super compact" setup with 28 and 46 tooth chainrings, mounted on the inner and middle positions of a triple crankset (with the outer position empty). With an 11-26 cassette, I get all of the gearing of the Apex groupset except the very top gear, but have nice tight spacing between my rear gears (plus the rings and chain are lighter than a 34-50 plus 11-32 combination would be). The jump between the two chainrings is a bit extreme, so I wouldn't recommend it for an inexperienced rider. For them, I always recommend a triple with a standard road cassette. And if they want even lower gears than come as standard with that (which is common because I live next to the Swiss Alps) then I'll switch their inner 30-tooth chainring for a 26-tooth ring BEFORE suggesting a wider range cassette (in that situation, the smaller chainring is a much cheaper and lighter option than a wider-range cassette).

My point is that to get a sufficiently low gear AND tight spacing you need a chainring that is smaller than the 34 tooth rings that come on compacts (and sometimes even smaller than the 30 tooth rings that come standard on triples). Achieving lower gears by using a wide-range cassette is not a smart way to do it. Whether you decide to use 3 chainrings or 2 is then up to you, but you need to start by having a sufficiently small inner ring and then figure out the rest of your gearing from there.

Thanks for the pdf PlatyPius. It lists the Q-factor of the Apex crank as 147mm. I have a Truvativ Rouleur triple crankset which is almost exactly the same as the SRAM Apex except that it is a triple, and it's Q-factor is actually one of the lowest of any intergrated-axle triple at 151mm. Therefore, all SRAM's hype about a lower Q-factor is concerning a 4mm difference, which I would consider to be un-noticeable/insignificant.

Last edited by Chris_W; 02-17-10 at 11:20 AM.
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