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Discussion Starter · #1 ·
Anyone using this combo up front?
Trying to set this up on a new build, but not having much luck with the front der. adjustment. Chain is getting stuck between the 42 and 39 rings.

Do I need to just keep trying, or is this just not gonna work? Any tips?

thanks-

ps. i know the gearing is almost identical, but that's what i have around -- trying to build with minimal new purchases
 

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Game on, b*tches!
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Why? If you're going to use that combo it would just be simpler (more simple?) to run a 1x9 or 10. IMHO....
 

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sounds like you may have chainrings reversed. Usually, they are not symmetrical. Flip one or both to check if the gap narrows. Some people do not recommend this - for safety reasons.
 

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duh...
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Kram said:
Why? If you're going to use that combo it would just be simpler (more simple?) to run a 1x9 or 10. IMHO....


I'm sure there are plenty of guys out there using that same exact combo... with all the teeth ground off the 42
 

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Number 2 on the course.
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FatTireFred said:
I'm sure there are plenty of guys out there using that same exact combo... with all the teeth ground off the 42
lol.

I would (did) pick one, disconnect the FD and adjust to limit screws so it keeps the chain from jumping off.

Assuming they are both inner chainrings, I suspect that good shifting with an indexed shifter will be elusive.
 

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veldrijder
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Single 39t is great, especially if you have an 11t on your cassette. 39 x 11-26 gets me around most courses, and I can use an 11-28 cassette for the occasional course with some hills.
 

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Discussion Starter · #9 ·
Excellent!

So, just about everyone thinks its a good idea then, huh?

(ha) Nah, I kind of expected these responses... was just wondering if anyone had done it. Guess not. Thanks anyway.
 

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I've run a 39-42 with 9-speed shimano with no problems. a narrower 10speed chain may fall between the rings, so you may need to follow carlosflanders' advice.

that ratio didn't offer much additional range (i use a 39-45 now), but i actually prefer having a front derailleur to a single front ring w/ chain guard. with the front derailleur, you at least have some chance of pedaling the chain back on if it drops.
 

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oh lonesome road for you
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I've known a lot of people to use 38 or 36 and 42. yes the ratios are close, but they swear by this gearing on muddy courses where your rear derailleur just stops working. They can still shift back and forth up front and while in the middle to top of the cassette this is apparently a useful little range.

I believe they use a SS 42 ring, though. I have a 38 inner and 42 ss chainring sitting around (well, the former is on the bike) and have though about trying them out. Of course, then I have to put the front shifter back on....so much work.
 

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I use 42/38 up front on my race bike and I like it. Both are BBB inner rings on a Dura Ace 10spd drivetrain. This works for me because I essentially race a single ring up front, if the course is fast I ride the 42, if it is muddy or hilly I ride the 38. There was only one course last year in BC that I shifted the front during the race. I looked at doing a dedictated single ring but it is not any lighter than my current set-up and not as versatile. It is also nice to do warm-up laps on the 38 and then race the 42. I have never dropped the chain in between the 2 rings.
 
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