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  1. #1
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    Ultegra inner chainring compatability?

    Ok guys, I have a question? I'm throwing around a idea in my head of maybe putting a smaller inner chainring on my Ultegra 6750 50/34 crank for when I do a steep long mountain climb. I know this will probaly raised some eyebrows, but i'm still having trouble getting up some of the mountains around here, I had to get off this weekend on a benefit ride and walk some. I ride about 3000 mi a year. Ok here's what I want to know. Can I put a 30t inner chainring on my 6750 crank(like when I know there is going to be a steep long climb on a ride) and it work ok. Will this be to big a drop from the 50t ring. Do they make a 30t that will work with my crank? Will this benefit me enough to be worth it. Before some suggest I run a bigger cassette I'm already running a 11-32, I know this should be plenty of gear, but its not, its not my legs that give out, its my lungs. I can't afford a triple setup right now, or I would go this route,(that's what both of my buddies are running that made it up all the way). Now this was a steep climb 2 plus miles, and we were told by the locals it was up to 15% grade a lot of the way.

  2. #2
    wim
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    I don't think there is a ring smaller than 33T for 110 BCD cranks. But let me throw this out: if your left shifter does triples, you could install a relatively cheap triple crank along with a cheap triple derailleur and be on your way. If you keep your compact and double derailleur, you could just go back to that setup once you've had enough climbing for the season.

    For what it's worth: This is basically what I do. I don't climb all that much any more, so I put my triple stuff (Sugino 48-36-26 with a 12-25 rear) on before I head for the hills once or twice a year. Out of sheer laziness, I left the triple derailleur on when I went back to the double a few weeks ago. It shifts my double (52-42) just fine. YMMV.

  3. #3
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    If you have a 34x32 low now, and that's not low enough, a triple is the only way to improve it. Wim is correct, you can't put anything smaller than 33 on a 110mm bcd crank.

  4. #4
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    You could get a Shimano SLX Chainset Double M665, about US$160. It comes as 36/22T. A bit low on the high end, but definitely low enough on the low end. You don't need new shifters nor do you need a new BB, though you may need to do some reinstallation.

  5. #5
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    33t won't work on all 110mm BCD cranks. On some cranks the chain side plates hit the arms.

    You could get a 10sp 11-36 MTB cassette. You may need a new derailleur to handle it. 11-34 is common and all MTB derailleurs can handle it but it's not that much change from your current 32.

  6. #6
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    Thanks quys for the reply's, that what I needed to know. I hadn't thought about a bigger gear cassette, that might work, as I have a Deore XT long cage derailleur already on. Would I probably need a longer chain if I used a 11-36? Currently have a 11-32.

  7. #7
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    Quote Originally Posted by Ventura Roubaix View Post
    Thanks quys for the reply's, that what I needed to know. I hadn't thought about a bigger gear cassette, that might work, as I have a Deore XT long cage derailleur already on. Would I probably need a longer chain if I used a 11-36? Currently have a 11-32.
    You will be able to get by using your current chain, just be careful not to cross chain, ie big front chainring with big back ring. If necessary, you can add a couple links(ask at your LBS) or get a new chain, but I'd just go with it.

  8. #8
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    Your current lowest gear is 34/32, or 1.1. With 34/36, you get down to 0.94. It's about like a largish shift, but just one.

    Going to a standard triple actually only gets you about the same change. 30/32 = 0.94. (Obviously I'm rounding some here, there's a difference, but it's less than 1% so whatever.)

    For someone who's able to finish all the climbs on his regular routes but wants it to be a little easier, it would be a useful change. I think you should go straight for the heavy artillery.



    VO Triple Crankset w/ 24t inner - Cranks - Cranksets - Components

    This gives you a 24t granny. 24/32 = 0.75, about 30% lower than what you're pushing now. And it's a road crankset with standard road bolt patterns. A 110 middle is a slightly unusual ring, but nothing you can't order. You don't give up much top end. Basically, you get the small gear you need now and you have the option of raising your gear ratios later if you find you want to.

    I haven't bought any of V-O's stuff, but it certainly looks pretty. I think Sugino does a compact triple crank too, check out rivbike.com. A little more expensive and according to some sources it ties you to Sugino chain rings. Not that that's a bad thing, necessarily.

    104/64 4-bolt cranks with bigger rings are certainly an option too, but I think there's something to be said for sticking with a touring crank based on a road bolt pattern.

  9. #9
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    Quote Originally Posted by AndrwSwitch View Post
    Your current lowest gear is 34/32, or 1.1. With 34/36, you get down to 0.94. It's about like a largish shift, but just one.

    Going to a standard triple actually only gets you about the same change. 30/32 = 0.94. (Obviously I'm rounding some here, there's a difference, but it's less than 1% so whatever.)

    For someone who's able to finish all the climbs on his regular routes but wants it to be a little easier, it would be a useful change. I think you should go straight for the heavy artillery.



    VO Triple Crankset w/ 24t inner - Cranks - Cranksets - Components

    This gives you a 24t granny. 24/32 = 0.75, about 30% lower than what you're pushing now. And it's a road crankset with standard road bolt patterns. A 110 middle is a slightly unusual ring, but nothing you can't order. You don't give up much top end. Basically, you get the small gear you need now and you have the option of raising your gear ratios later if you find you want to.

    I haven't bought any of V-O's stuff, but it certainly looks pretty. I think Sugino does a compact triple crank too, check out rivbike.com. A little more expensive and according to some sources it ties you to Sugino chain rings. Not that that's a bad thing, necessarily.

    104/64 4-bolt cranks with bigger rings are certainly an option too, but I think there's something to be said for sticking with a touring crank based on a road bolt pattern.
    A couple of questions? Is this crank going to work with my Shimano shifters (105's, I think 5500 series currently a compact setup). Will I have to change bottom bracket currently a 6700 Ultegra?

  10. #10
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    No, and no.

    You'll need a left shifter that can shift a triple. That would have a model number ending in 03. So, 5503 for example. You can sometimes buy loose left shifters. You'd also want a triple front derailleur. So, it's an expensive change. But it's a pretty significant difference.

    It's a very different bottom bracket standard. But they fit the same frame, so you're good there. And the bottom bracket for this crank is a very common standard, so you can get anything from a $15-$30 Shimano model that does the job fine to something for around $200. In case you hadn't guessed, I get the $20 ones.

    So it's not the cheapest change you could make. I don't like the word "upgrade," usually it's vain people applying it to bolting stupid, expensive things to their bike. However, having appropriate gearing will help you to be a more efficient rider. I think you'll find you enjoy your hillier rides more, and improve your times on climbs.

  11. #11
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    Quote Originally Posted by AndrwSwitch View Post
    No, and no.

    You'll need a left shifter that can shift a triple. That would have a model number ending in 03. So, 5503 for example. You can sometimes buy loose left shifters. You'd also want a triple front derailleur. So, it's an expensive change. But it's a pretty significant difference.

    It's a very different bottom bracket standard. But they fit the same frame, so you're good there. And the bottom bracket for this crank is a very common standard, so you can get anything from a $15-$30 Shimano model that does the job fine to something for around $200. In case you hadn't guessed, I get the $20 ones.

    So it's not the cheapest change you could make. I don't like the word "upgrade," usually it's vain people applying it to bolting stupid, expensive things to their bike. However, having appropriate gearing will help you to be a more efficient rider. I think you'll find you enjoy your hillier rides more, and improve your times on climbs.
    Thanks for the reply, not sure i'm ready to go that route just yet, I have to do most of my on mech work,(closet shop over 1 hr away) an i'm not sure i'm ready to tackle something that big yet. I am already running a long cage Deore XT RD, so i'm thinking of trying a 11 or 12-36 cassette.
    m

  12. #12
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    I was about to say "it's not a terribly difficult change." But it's probably one of the hardest on a bike. I just don't think any of them are all that hard. And to be honest, crankset swaps are something I usually get done at the shop.

    To do it at home, you'll need both the tool to remove the old BB, if you don't already have it, and a specialized tool for the new one. Neither is terribly expensive, but they're expensive enough that if you didn't also have to spend an extra three hours of your time on going to the shop, just getting it done has been the more attractive option for me most of the time.

    I hope the 36t ring is enough lower for you. I don't know how long you've been riding, but sometimes cleaning up your form can help with climbs too.

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