trek 520 gearing - chainring swapout
08-11-08, 04:37 PM
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trek 520 gearing - chainring swapout
i have a 2007 trek 520 with the stock Shimano 105 52/42/30 triple. i'm heading to the dolomites for touring next month and need to lower my gearing. instead of swapping out the crankset i'm thinking of just getting some new chainrings. i'm thinking 46/36/24 to keep the 22 differential between big and small ring as well as to only have a 10 differential on the big and medium (since this is where i'll be doing most of my shifting/would want the smoothest movement). does anyone have any thoughts on this/do you think it might be worth going even lower-- say 44/34/22? additionally, does anyone have suggestions on good, cheap replacement rings? (i believe these are 5 bolt, 74cm).
08-11-08, 04:52 PM
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i have a 2007 trek 520 with the stock Shimano 105 52/42/30 triple. i'm heading to the dolomites for touring next month and need to lower my gearing. instead of swapping out the crankset i'm thinking of just getting some new chainrings. i'm thinking 46/36/24 to keep the 22 differential between big and small ring as well as to only have a 10 differential on the big and medium (since this is where i'll be doing most of my shifting/would want the smoothest movement). does anyone have any thoughts on this/do you think it might be worth going even lower-- say 44/34/22? additionally, does anyone have suggestions on good, cheap replacement rings? (i believe these are 5 bolt, 74cm).
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Plan Epsilon Around Lake Michigan in the era of Covid
Old School…When It Wasn’t Ancient bikepacking
Gold Fever Three days of dirt in Colorado
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Stuart Black
Plan Epsilon Around Lake Michigan in the era of Covid
Old School…When It Wasn’t Ancient bikepacking
Gold Fever Three days of dirt in Colorado
Pokin' around the Poconos A cold ride around Lake Erie
Dinosaurs in Colorado A mountain bike guide to the Purgatory Canyon dinosaur trackway
Solo Without Pie. The search for pie in the Midwest.
Picking the Scablands. Washington and Oregon, 2005. Pie and spiders on the Columbia River!
08-11-08, 05:30 PM
#3
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Set my 520 up as a 2x9 with 28 and 39 chain rings plus 11-34 cassette.
Was hoping for a 24 or 26 chain ring, but it didn't shift as well; however this set up gives a 22-97 gear in range which so far has worked well.
Was hoping for a 24 or 26 chain ring, but it didn't shift as well; however this set up gives a 22-97 gear in range which so far has worked well.
08-11-08, 06:37 PM
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The inner BCD is 74mm which will take a 24 tooth ring. The outer is a 130 mm BCD and the lowest you can go is a 38. A 50/38 isn't bad but the 3 rings will probably cost you what a good ISIS/Octalink mountain bike crank will cost. Expect to pay $30 to $40 each (or more).
