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Down tube shifters

Old 03-05-21, 06:05 AM
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joehayes999
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Down tube shifters

I am rebuilding an old steel racer with Huret shifters and an Allvit derailleur. This is a very amateur question but am I correct is saying that shifter only stays in it's given position by the screw on the shifter being tight enough. So the mechanics of it is shifting to a smaller cog is done by the derailleur pushing outwards as it naturally will and shifting to a bigger cog is done by the shifter pulling the derailleur inwards and the shifter itself holding in place. My issue is the shifter is not holding in place, when I pull it towards me it goes back to the full forward position and I think this is simply because the screw is not tight enough.
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Old 03-05-21, 06:24 AM
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DOS
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Yes this is correct assuming you have any washers and bushing for the lever correctly installed. The reason many levers have a d ring mounting screw is to make fine adjustments easy. You shouldn’t have to go beyond finger tight to get it to hold. Also, you don’t need a ton of cable tension when setting up initially. Just pull the cable taught and attach to the derailleur.

Last edited by DOS; 03-10-21 at 05:06 AM.
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Old 03-05-21, 07:32 AM
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Correct
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Old 03-05-21, 09:00 AM
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Sounds like a missing or greased up friction washer. But sometimes the needed friction setting makes shifting harder. If your frame's rear is spaced at or can be cold set to 126mm then think about a 7-speed indexed upgrade. It should be possible to find a used Shimano DT shifter and a compatible derailleur. The indents do a good job of holding the setting without a lot of lever effort in shifting. DT index shifting is very reliable and easy to use as long as you are on drop bars.
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Old 03-05-21, 09:30 AM
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sovende
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“Friction” is key to the proper function of friction shifters! I’d check to make sure that the shift lever assembly is properly assembled and that the contact surfaces are clean, smooth and free of lubricant. As mentioned, some shift levers have a D-ring or tiny wing nut like arrangement to allow adjusting the degree of friction that holds the level in any given position. As also mentioned, if “finger tight” isn’t sufficient, something’s not right.
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Old 03-05-21, 09:46 AM
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55murray
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Also, that is pretty much the last thing you worry about, after the FD and RD are clean and moving freely with decent spring tension, and all cables and and housings are replaced.
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Old 03-05-21, 11:14 AM
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HTupolev
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Originally Posted by joehayes999
I am rebuilding an old steel racer with Huret shifters and an Allvit derailleur. This is a very amateur question but am I correct is saying that shifter only stays in it's given position by the screw on the shifter being tight enough. So the mechanics of it is shifting to a smaller cog is done by the derailleur pushing outwards as it naturally will and shifting to a bigger cog is done by the shifter pulling the derailleur inwards and the shifter itself holding in place. My issue is the shifter is not holding in place, when I pull it towards me it goes back to the full forward position and I think this is simply because the screw is not tight enough.
Yes. They usually work pretty well assuming they're properly assembled... which unfortunately can be tricky, because sometimes they have a surprisingly large amount of internal parts all lined up on the bolt. If the front shifter is holding properly and the rear shifter isn't, one thing you might do is disassemble the two shifters piece by piece - very carefully keeping track of everything and what direction it mounts - and seeing whether the two shifters match.

If the issue is really marginal - like if it's mostly working but you're having to occasionally tighten it up during a ride - then you could try hitting the threads of the bolt with a bit of a not-super-aggressive threadlocker like blue Loctite.
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Old 03-05-21, 01:01 PM
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Originally Posted by sovende
“Friction” is key to the proper function of friction shifters! I’d check to make sure that the shift lever assembly is properly assembled and that the contact surfaces are clean, smooth and free of lubricant. As mentioned, some shift levers have a D-ring or tiny wing nut like arrangement to allow adjusting the degree of friction that holds the level in any given position. As also mentioned, if “finger tight” isn’t sufficient, something’s not right.
Check any plastic parts carefully as they tend to crack.
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Old 03-06-21, 08:07 AM
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Make sure you have all the pieces and that they are installed in the proper order and orientation. You don't say what model levers you have, but perhaps this thread and its illustrations might help:

https://www.bikeforums.net/classic-v...n-diagram.html
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