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  1. #1
    Senior Member arkansasgal's Avatar
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    Problem with Crank/Chainring combo

    Hey guys and gals -- I have a triple crank Cannondale Synapse which I love. I have put a lot of miles on the bike, and it was time to put a new chain on Orange Crush. At the same time, the LBS thought I should put on a new chainring. The original crank is a Truvativ and they put a Shimano chainring on simply because they wanted to get me out riding and did not have a Truvativ chainring. I am having some problems shifting into the small ring. The LBS says they think I need to put a Shimano crank on to replace the Truvativ, and this will make the shifting problem a lot better.

    I know there are sometimes shifting problems with a triple, but, until now, have not felt the problems were enought of a handicap to switch to a compact double, which has been suggested. I do a lot of hills and like having the lower gears on a triple.

    Any comments or experiences with this problem would be appreciated.

    Arkansasgal

  2. #2
    ES&D t4mv's Avatar
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    Is there a big diff between the middle ring and the small ring? Even if you had 42 middle and a 30 small (or whatever) the triple FD has to be able to kick it over onto the small ring (usually overshifts, in my experience). So you can help things along by adjusting the angle of the FD's rear outer cage plate hitting the chain on the way down. Depending on how you use the cassette on the back determines how much angle you're going to put into the FD. The determining factor is how much adjustment before the chain overshifts, because the chainline on a triple is obviously sharper than a double (if you cross chain).

    I guess the question for starters is, how is the chain or c'ring not shifting to you satisfaction?

  3. #3
    gone ride'n cyclinfool's Avatar
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    I'm not sure I buy it. Sounds like they want you to purchase more stuff. However I would yield to those with more experience here. I suspect they just haven't got the FD adjusted just right. Triples can be finaky and the adjustment is always a bit of a tradeoff.
    "Of all the things I ever lost I miss my mind the most." Mark Twain
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  4. #4
    Rides again HiYoSilver's Avatar
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    Don't think it's the crank. I have a truvativ/{sram** crank. It's more with the adjustment of the shifters. could they have tried to force a 10 chain on a 9 speed shifter combo?
    Hi 'o Silver away

  5. #5
    just keep riding BluesDawg's Avatar
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    First they sell you a mismatched chainring. Then you start having shifting problems. Now their solution is to change the crank to match the chainring?
    The more you ride your bike, the less your ass will hurt.

  6. #6
    Senior Member BikeArkansas's Avatar
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    Got to go with BluesDawg on this. They dug a hole and want you to pay to get out of it.

    However, I will also say that IMHO nothing shifts like a Shimano system. If you are stuck paying the way out of the hole go wtih the Shimano.
    I started riding my bike to get healthy. Now I try to stay healthy so I can ride my bike.

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    Did they replace all three chainrings, two of them, just the small one?

  8. #8
    Senior Member arkansasgal's Avatar
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    They didn't sell me the Shimano chainrings (all three) - they put them on at no cost because they did not have Truvativ chainrings. They actually had a Shimano crank, but no bottom bracket. They say they will order a bottom bracket and sell me the Shimano crank and bracket for less than it would cost to buy the Truvativ chainrings. I really feel they have gone out of their way to fix the problem. I had a ride scheduled with out-of-town company and they did what they could to get me back riding. So now we just have to do what we can to fix the problem. They seem to think the Shimano crank and chainring will do that.

    Thanks guys for your comments.

  9. #9
    just keep riding BluesDawg's Avatar
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    Oh. That's different. It is often true that it is cheaper to buy a whole new crankset than a full set of replacement rings. Hope it works out for you.
    The more you ride your bike, the less your ass will hurt.

  10. #10
    OM boy cyclezen's Avatar
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    1st
    how many miles do you have on the original setup?
    chainrings generally, especially the 'new' ones (those made in the last 10-15 yrs) last an awful long time under serious hard ridin.
    replacing a chain doesn' mean you have to replace the front rings.
    more common is to wear the chain so much that one or 2 rear cogs (those ridden the most) may wear a bit too much.
    I have a Truvatic elita triple which has at least 15K miles on it and the rings are way fine.
    Not seeing your setup, I would still say the greater possibilities are
    A. nosepicker really doesn't what he's talkin about
    B. trying to sell you something you don;t need
    C. covering some screwup

    I'm always suspect of the 'something for nothing' deal, just because you're sucha good customer and we want to get you back on the road...

    Shimano rings work fine on a truvativ crank ... and they are really nice rings.
    triples work fine, if setup properly.
    that said, a Shimano 105 or Ultegra triple is a nice crankset.
    truvativ makes good stuff also.
    if there is something 'wrong' with the truvativ cranks and rings, then they need to demonstrate the problem. This **** is not magical, smoke and mirrors stuff. Only their bull**** is smoke and mirrors.
    Problems in the cable run (dirt, rust, kinks, etc.), worn and flimsy cables often cause problems which can be put onto the rest of the main drive train. A nice braided cable will set you back maybe $4 or $5 bucks.
    cable housing issues (and hangups here cables enter and leave bosses and housing, like the BB area) can also contribute to shifting problems. Often its the combination of crappy cables, cable path and clogged housings which together make shifting an adventure.
    Then, per the nosepicker, you give them $150+ bucks for a new crankset, and it doesn;t resolve the issues.
    I always start with the simplest and least expensive area if the problem isn;t clear. $8 for 2 new cables is money well spent if you've never replaced them and the bike is a couple seasons old.
    Then I make sure the housings are clean (not clogged with crud) and not kinked. Kinked gets replaced.
    also not a big ticket item, but a real improvement over worn housings

    everyone should have a chain checker. Park tools CC-3, nashbar and performancebike also have same tool for a bit less dough. All work real fine.
    Even if a rider doesn't want to do the maintenance, you can still do the easy 15 seconds check of the chain condition and know exactly when to 'replace' the chain (I replace when checker shows .75% stretch). a no-brainer. And it assure much longer 'life' out of the cassette cogs and rings.

    ...next they'll be chargin you to replace the blinker fluid...
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  11. #11
    Senior Member Garfield Cat's Avatar
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    How would you like a brand new bike?

  12. #12
    Time for a change. stapfam's Avatar
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    Quote Originally Posted by cyclinfool View Post
    I'm not sure I buy it. Sounds like they want you to purchase more stuff. However I would yield to those with more experience here. I suspect they just haven't got the FD adjusted just right. Triples can be finaky and the adjustment is always a bit of a tradeoff.
    Have to agree as I run Truvativ cranks and run a Shimano small ring with no problems. Admittedly this is on the doubles on the road bike- but The Mountain bikes have a complete mismatch of rings on them and still no problems.

    And if all 3 rings have been replaced with the Shimano ones- All the crankset is doing is acting as a carrier for a new set of rings. And if given a choice- I would buy the truvativ cranksets over shimano any day- Mainly because they are cheaper but also because they have the other factor I like- Long life rings.
    How long was I in the army? Five foot seven.


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  13. #13
    Senior Member BlazingPedals's Avatar
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    The cranks are just a thing to mount rings to; it doesn't matter the brand. If you get the Shimano cranks, you'll have the same issue; but the shop will try harder to figure out what's *really* wrong.

  14. #14
    Senior Member arkansasgal's Avatar
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    I spoke with several other large bike shops and with the Tech Dept. at Shimano. They all agreed that there might be enough difference in the machining of the two parts to cause a problem. I guess we will all find out when they put the new crank on and, if the problem is not solved, perhaps they will work harder to find out what is "really" wrong. I dealt with the problem today by doing a 37 mile ride and just getting rid of some of the frustration.

    Thanks for all your comments.

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