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Suntour GPX Accushift question.

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Suntour GPX Accushift question.

Old 07-13-19, 03:39 AM
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robertj298
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Suntour GPX Accushift question.

My 89 Ironman is equipped with suntour gpx accushift shifters and derailleurs with a 7 speed freewheel.
I'm wondering why the shifters will click 8 times instead of 7 ? It will shift 1-7 and then it will click one more time like it has an 8th gear
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Old 07-13-19, 07:36 AM
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Same with my GPX shifter. But so do my indexed Shimano bar-end 8-speed and Dura Ace 7-speed downtube shifters. There's an extra click, but it doesn't appear to give enough throw to make an 8-speed out of a 7-speed or 9-speed out of an 8-speed.
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Old 07-13-19, 08:00 AM
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Originally Posted by canklecat View Post
Same with my GPX shifter. But so do my indexed Shimano bar-end 8-speed and Dura Ace 7-speed downtube shifters. There's an extra click, but it doesn't appear to give enough throw to make an 8-speed out of a 7-speed or 9-speed out of an 8-speed.
So if you couldn't use it on an 8 speed freewheel why is it there?
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Old 07-13-19, 08:22 AM
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Dunno. My best guess is the extra click or detent may be part of the machining process to ensure accurate alignment of the actual indexing detents.

BTW, some 7-speed shifters and rear derailleurs will cover an 8-speed cassette, but usually only in friction mode. I have an old 6-speed Shimano 600 rear derailleur that will work on my Ironman in all 7-speeds -- friction only. On my Univega Via Carisma I have an 8-speed cassette and 8-speed bar-end shifter, but the 7-speed Exage rear derailleur will cover 8 speeds only in friction mode. It'll click into the big cog on the 8-speed cassette but won't hold position under pedaling pressure -- it'll ghost shift down. But it'll work fine in friction mode, so that's how I use it.
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Old 07-13-19, 02:01 PM
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Superb Pro and Sprint downtube shifters will index 11 times in 180 degrees. If the Gpx only go 8 maby new enough for 8 speed Suntour?
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