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rebuilding a Shimano 7 speed shifter?

I have  a hard rock bicycle with a Shimano 7 speed rear axle and a Shimano three speed front sprocket.  Neither shifter will work.  Is there a way to fix these?

Aron3131 year ago
Sounds like you could use a new bike if you would bring it to the bike shop and pay over $100 to get it fixed. First check the cables. Main problem with locked up derailleurs!
NachoMahma3 years ago
.  Depends on what the problem is.
.  Stuck control levers?
.  Rusted or bound cables?
.  Broken derailleur?
jay oliver (author)  NachoMahma3 years ago
Thank you for your interest. Both of the shifters are stuck in the high end and will not begin to return down the line - engaging the other gears.

Joe
.  Sounds to me like your best bet would be to do a complete teardown. Clean and lube everything and re-assemble. Adjust as needed. http://www.google.com/search?q=derailleur+rebuild 
seandogue3 years ago
Yes.

Unless you are planning to take the bike to a shop for repair...that is,if you intend to learn to take care of your bike (which imo everyone should do), the single best investment you can make is to purchase a bike repair manual. They are not expensive, unless you get all snooty. I've been working on bicycles since I was seven years old, (that works out to 44 years I've been at it) and I can tell you, that unless you're designing bikes and are really *way up there, a five to ten dollar paperback (or thereabouts) is all you need to keep the bike in top conditions, failing a catastrophic accident which might need professional help.

1) check the cables to ensure that they are clamped securely at their termini

2) check that the derailleurs are secured to the frame. The front derailleur attaches to the column that the seat goes into. make sure it doesn't move when you try to twist it. If it does, tighten the clamp screw. if that doesn't work, try inserting a small band of an old inner tube between the derailleur clamp and the tube and retighten.
The rear derailleur should be attached the rear fork and is often held in place by the rear wheel. Ensure that it is secured.

3) Adjust the derailleurs... This is best done using a bike maintenance book. The local library is a good place to find one, or purchase a copy at your local bike shop or book store. Directions can also be found online. Search for derailleur adjustment instructions

4) clean, oil blah blah, standard maintenance...Keeping the bike clean is a good way to prevent many of the problems we encounter.
A stiff nylon brush is good for getting caked mud (dried!) and road dirt off the mechanical components, optionally followed by hosing the bicycle down and drying it.

If this fails, or if you have no mechanical inclination, then you might want to consider taking the bike to a shop and have them have a look to see what needs to be replaced.
Also depends on which model shifter. I have fixed two sets of these. One was just gunked up with old grease and dirt. A little bit of light weight oil and parts cleaner got them moving again then I re-greased them and put them back into service. Another set had a inconsistent skipping in and out of the gears. I took them apart and found the head of a couple old cables jammed in the mechanism. Once removed they worked great.

S
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