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Old 06-24-10, 12:20 PM   #1
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Will a Shimano SG G-26 granny gear fit on a 105 triple crank?

I'm considering a 26 or 28t granny gear for my Shimano 105 Crankset. The crank now has 50, 39 & 30t chainrings. I'm using a 105 triple front derailluer and an Ultegra GS rear derailluer.

I'm using a 10 speed chain.

The SG G-26 is the correct 74 BCD, but is discribed as a MTB chainring: http://cgi.ebay.com/Shimano-SG-G-26-...92346847569163

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Old 06-24-10, 12:57 PM   #2
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Since the BCD matches, it should fit. It's likely listed as a MTB chainring simply because road bikes never come equipped with such a small chainring. Your deraillers should have no trouble handling that chainring swap either. I'm running a 52/42/28 triple on my commuter with the same deraillers (9 speed versions) with a 12/27 cassette.
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Old 06-24-10, 04:47 PM   #3
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"Fits most mountain bike cranks" ?1? 110/74 BCD cranks haven't been used much on mountain bikes for about 15 years!

It'll fit. You may need a chain watcher to prevent the chain from falling off the inside on down shifts but then probably not since your middle ring is 39 and not 42 so the jump isn't so large.
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Old 06-24-10, 11:57 PM   #4
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Originally Posted by Barrettscv View Post
I'm considering a 26 or 28t granny gear for my Shimano 105 Crankset. The crank now has 50, 39 & 30t chainrings. I'm using a 105 triple front derailluer and an Ultegra GS rear derailluer.

I'm using a 10 speed chain.

The SG G-26 is the correct 74 BCD, but is discribed as a MTB chainring: http://cgi.ebay.com/Shimano-SG-G-26-...92346847569163
Yes. I have a variety of chainrings on my Ultegra crank:
http://home.comcast.net/~jeff_wills/...-grr%20008.htm
That's SR, a Shimano, and a Sugino rings on a Shimano crank. As long as the bolt circle matches, the rings don't care.
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Old 06-25-10, 10:09 AM   #5
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This is the chain ring mentioned by OP.

Why the strange-shaped attachment tabs, and why the 2nd set of holes?

Also, it just says "steel"--Is that stainless, or is it going to rust like a chain, or does anybody know?

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Old 06-25-10, 11:43 AM   #6
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bump
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Old 06-25-10, 11:45 AM   #7
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I can answer part of your question. Steel means steel. It will have a protective coating on it (similar to cassettes) but if left out in the elements long enough, it will rust. I had two steel chainrings on a bike that I frequently used at the beach for several years. I never had a rust problem on the chainrings.
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Old 06-25-10, 12:42 PM   #8
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It fits 2 different bolt patterns.74 and 58 or something.
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Old 06-25-10, 12:53 PM   #9
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It fits 2 different bolt patterns.74 and 58 or something.
Doubtful. Those inner holes are much too small for any chainring bolt that I've seen.
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Old 06-25-10, 01:14 PM   #10
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Doubtful. Those inner holes are much too small for any chainring bolt that I've seen.
Yeah, those inner holes just look too small for anything I can imagine. I asked the guy who's selling them on ebay--If and when he replies, I'll post the answer here.

I have 2 105 triple cranksets that are crying out for something like this--and the cheapest steel I've been able to locate before today is Blackspire stainless, $30+. The way you describe this steel, apparently carbon steel, should work just fine for me; so I save $40 if i buy 2 of these.

Thanks for the help!
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Old 06-26-10, 03:22 PM   #11
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After giving this a lot of thought, I don't think this granny will work on a 105 triple crankset with external bottom bracket. Just eyeballing how far those tabs extend in toward the axle of the bb, it looks like they would hit the external bearings (Hollowtech II). On a square-taper bb they'd be fine.
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Old 06-26-10, 04:43 PM   #12
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Trim the tabs back and add a little black paint.
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Old 06-26-10, 05:03 PM   #13
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Living in a small high-rise apartment, no way to trim. Take it somewhere to get it done, I've lost the price advantage. Not worth it.

i heard back from the seller--Don't know Jack about Jack. Forget it.
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Old 06-26-10, 05:11 PM   #14
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Get a 24t small ring. It will work and you will have a very low gear when you need it. You can find them without the extra metal on the mounting tabs. I have put them on my friends bikes and on my RAAM rider's climbing bike.
The shift from the smaller ring to the middle won't be smoothly indexed, but with practice it works fine.
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Old 06-26-10, 05:29 PM   #15
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I already have, but aluminum.

I'd like to replace with steel when the alum wears out.
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Old 06-27-10, 08:47 PM   #16
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Originally Posted by ClarkinHawaii View Post
This is the chain ring mentioned by OP.

Why the strange-shaped attachment tabs, and why the 2nd set of holes?
The inward-projecting tabs prevent a dropped chain from getting jammed between the frame and the chainring. Moot point now.

If you're still looking, try to find an old SR Ninja chainring. Steel, silver, very, very durable. No inward chain de-jammers.
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Old 06-28-10, 09:11 AM   #17
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Originally Posted by ClarkinHawaii View Post
I already have, but aluminum.

I'd like to replace with steel when the alum wears out.
Unless you spend hours in the granny ring on a daily basis, you will never wear out the Al chainring.
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Old 06-28-10, 03:35 PM   #18
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The inward-projecting tabs prevent a dropped chain from getting jammed between the frame and the chainring. Moot point now.

If you're still looking, try to find an old SR Ninja chainring. Steel, silver, very, very durable. No inward chain de-jammers.
Looking at Ninjas now. Thanks
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Old 06-28-10, 03:38 PM   #19
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Unless you spend hours in the granny ring on a daily basis, you will never wear out the Al chainring.
You and opthers have told me this before; and you are probably correct. All I know is that I wince every time the chain falls ker-chunk from the 39t ring to the aluminum 24t.

What it boils down to is that I'm not buying just a steel chain ring--I'm also buying peace of mind and freedom from wincing.
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