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Top normal front derailleur

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Old 02-16-10 | 03:25 PM
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Top normal front derailleur

I'm having an issue that perhaps some of you have had - the front derailleur on my Univega Gran Turismo (1980), a Suntour Vx, can't shift into the smallest chainring (triple crank) under load. It's a low-normal derailleur, and either the spring just isn't strong enough or it's worn out , but I think a top normal model would allow me to yank it into gear with some pressure on the pedals.

If I'm not mistaken, I thought that was one of Suntour's major innovations, the top normal front derailleur. Why isn't mine like that, and which models should I look out for?
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Old 02-16-10 | 05:16 PM
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Before you go searching out a new derailleur, check the cable to make sure it isn't at fault. Just release the cable bolt and if the derailleur moves further inward, it's likely the cable. Sometimes you can increase spring tension sufficiently by slipping a piece of tubing over the spring ends. Also make sure the travel limit screws are properly set.

I don't know when SunTour switched the operation of their front derailleurs, but I can guess why. Even though their approach made more technical sense, it wasn't the normal operation and it was confusing people. Shimano's Rapid Rise rear derailleurs also used the spring to facilitate shifts onto larger cogs and they didn't catch on either. IIRC correctly both the SunTour Spirt and SunTour Compe V were the reverse action front derailleurs, though I don't know if they have sufficient travel for a triple.
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Old 02-16-10 | 11:22 PM
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Originally Posted by T-Mar
IIRC correctly both the SunTour Spirt and SunTour Compe V were the reverse action front derailleurs, though I don't know if they have sufficient travel for a triple.
I am using a Compe V, it does have the reverse action and I am using it with a triple.
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Old 02-16-10 | 11:40 PM
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Thanks for the advice. It's about time for a deep cleaning. Maybe it'll shape up after I degrime everything and add some lubrication, cable adjustment, etc. Good to know those top normal fronts will shift a triple.
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Old 02-16-10 | 11:48 PM
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ixnay on the pirtsay - I had to switch to an XCD to run triple on the grocery-getter. The Spirt will just barely swing a triple at the extremes of its adjustment and uses EVERY click of the Bar-Con. So, under a load uphill you really have to yank some cable. Not ideal. (YMMV.)
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Old 09-17-11 | 07:06 PM
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I've got an old Compe V that I am trying to set up and the shifter isn't making it move down from the upper position. Anyone have any advice for setting these up? I am able to manually move the swing-arm...
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Old 09-17-11 | 08:13 PM
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Originally Posted by T-Mar
I don't know when SunTour switched the operation of their front derailleurs, but I can guess why. Even though their approach made more technical sense, it wasn't the normal operation and it was confusing people. Shimano's Rapid Rise rear derailleurs also used the spring to facilitate shifts onto larger cogs and they didn't catch on either. IIRC correctly both the SunTour Spirt and SunTour Compe V were the reverse action front derailleurs, though I don't know if they have sufficient travel for a triple.
A top normal FD makes sense if you're running straight crossover gearing, where you never have to double shift. But if you're running gearing that does require double shifts--especially half-step gearing, where every other shift is a double shift--it makes no sense, because it's very inconvenient to have to move the levers in opposite directions when double shifting. With a low-normal FD, you move both levers in the same direction to double shift.
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Old 09-17-11 | 08:23 PM
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I use a Compe V, but I also use a TA double with 48 -30. I like having it default to my 48.
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Old 09-17-11 | 11:09 PM
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I think I may have found my problem. Some more research led me to this thread:
"High Normal Front Derailleur"
https://www.bikeforums.net/showthread...ont-Derailleur

and this:

My one bike has a Suntour COMPE V front derailleur that normals to high. The cable attaches to the bracket attached to the seat post and does not move. The cable housing attaches to the mechanism that actually moves. The cable housing shifts the gears, not the center cable.
The old Gitane* I pulled it from had two cable stops for it. One that left exposed cable for most of the down tube and another for a short run of housing under the bottom bracket to the derailleur. I only have one of those plastic cable guides screwed to the bottom of my bottom bracket and assumed it would be okay to run bare cable to the clamp on the derailleur. Any suggestions short of brazing on a cable stop?


* Likely a pre '72 given that the front derailleur lacks a date code, just a four digit number!
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Old 09-18-11 | 11:50 AM
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There was also a Suntour XC triple reverse pull front derailleur.
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