Lowering Gear Inch (Ultegra 6700)
Hi all,
I'm just getting back into cycling after 5 months off with knee problems (ITBS and torn ligament). My legs aren't quite upto what they should be and my standard 53/39 chainset is hurting! My initial thought was to change it for a compact 50/34 option and throw on a 12-27 cassette (running 12/25 atm), but I've been given a 12-30 Tiagra 10-speed cassette which I'm tempted to use.
I've spoken to a few buddies and it seems it will work fine with the 6700 rear derailleur; therefore am I right saying that 39 at the front with a 30 on the back is almost identical in GI to 34 on the front and 27 on the back?
Ta
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I'm just getting back into cycling after 5 months off with knee problems (ITBS and torn ligament). My legs aren't quite upto what they should be and my standard 53/39 chainset is hurting! My initial thought was to change it for a compact 50/34 option and throw on a 12-27 cassette (running 12/25 atm), but I've been given a 12-30 Tiagra 10-speed cassette which I'm tempted to use.
I've spoken to a few buddies and it seems it will work fine with the 6700 rear derailleur; therefore am I right saying that 39 at the front with a 30 on the back is almost identical in GI to 34 on the front and 27 on the back?
Ta
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0
Comments
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39/30 = 34.2 inches, 34/27 = 33.1 inches. Dropping your 39 to 38 would make them almost identical.0
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How much drop can you have from a 53 then? Could I just be cheeky and throw on a 34 or is that a bit extreme?0
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Dropping to a 34 would cause all sorts of problems as your derailleurs couldn't handle it, but then it's not possible anyway. On a 130mm BCD crank (I'm assuming it's Shimano) 38 teeth is the smallest ring you can fit.0
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I'll install the cassette and see how that feels, in the mean time i'll try and grab a compact crank as well0
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I use a Tiagra 12-30 cassette on my compact and it is great for getting up hills if needed.0
