# 2008 555 chainring Q???



## brucemx372 (Mar 24, 2009)

Hi Guys, i am new to this forum and new to road biking.....anyhow, i took my 2008 555 for its first ride this weekend, but even in my newbie status, the gearing seems off- in top gear i was spun out at 90rpms and 30mph and i feel like i need bigger chainrings....does anyone know what ultegra cranks the 2008 555 is running and what replacement chain rings i can use????


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## nealrab (Aug 6, 2002)

*Well that depends....*

on the crankset assembled. I have a 34/50 chainring with a 12-27 cassette, but of course there's no standard here. It could have been assembled with a triple 52-39-30 or some variation of that, or a standard double 53-39. Where is your spec sheet from the purchase? Or you could look on the chainring for the sizing, or you could count the teeth...All sizing of cranksets and cassettes should be stamped on the set or looking vertically into the cassette for the sizing stamp. I sure wouldn't switch out anything until you've ridden for at least 2-3 months to get the feel of everything. Certainly don't judge gearing going downhill or with a tailwind...


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## brucemx372 (Mar 24, 2009)

thanks Neal....i forgot to mention, its the 12-27 cassette and the compact crank with definately a 50 and i think the 36 as the smaller chainring. Even on this first ride or two, i found myself mainly on the big chainring and running a good cadence- i was hoping to goto a 53-39, so i suppose the real question i want to know is which ultegra chain rings will be compatible with my ultegra crankset??? when i searched, there seemed to be several types of ultegra stuff. i looked at the stuff that came with the bike but i couldnt find the spec.

cheers, bruce


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## brucemx372 (Mar 24, 2009)

tell-a-lie, its actually a 50-34 compact crankset.....oh yeah, i am not too worried about climbing since its so flat here in the midwest!


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## wuggabugga (Oct 3, 2005)

Have you thought about a cheaper interim solution of changing the current 12-27 rear casette to a 11-23? I've seen Ultegra casettes for aroung $60. Take a peek at some of the gear ratio calcultors. Here's one at http://www.bikeschool.com/gearcalc/gear_calc.cgi


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## chas (Aug 10, 2006)

brucemx372 said:


> tell-a-lie, its actually a 50-34 compact crankset.....oh yeah, i am not too worried about climbing since its so flat here in the midwest!


Hi Bruce,

With the compact up front, and a 12-27 in the rear, I think the easiest way to gear up would be to swap to an 11-25 rear cassette. A standard 53t chainring and a 12t cog gives you approx 119 gear inches, while your 50t / 12t setup results in 112.5 inches. If you made the swap to an 11-25 cassette and kept your 50t chainring, you would have a high end of almost 123 gear inches. Here's a basic gear chart that I've found to be pretty helpful: http://home.i1.net/~dwolfe/gerz/


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## brucemx372 (Mar 24, 2009)

thanks guys, i didnt realize shimano made a 11-25 cassette....a much easier option for sure!


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