Shimano Altus A20 help?

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Hi y'all!

I inherited a Giant bicycle, three sprockets up front and seven in the rear, with Shimano Altus A20 shifting levers on both sides. I guess some of you folks with the budget might be snickering, but this is the very best bike I EVER owned. Problem is that for some reason, though it worked fine before we moved, after the movers delivered it, neither shifter wants to do much. The front will still switch between two sprockets, but the back is not shifting at all. If I pull on the back cable I can cause it to switch gears as long as tension is maintained.

I am guessing a good place to start is the shifters, but after opening them up I see these are a bit complex, and to guess at what should be right is not my first wish. I can not access any tech diagrams on the Shimano site and can't find any Googling - can anyone offer an alternative (If I had the spare funds I would take it to a shop, but that is not an option)?

Hi y'all!

I inherited a Giant bicycle, three sprockets up front and seven in the rear, with Shimano Altus A20 shifting levers on both sides. I guess some of you folks with the budget might be snickering, but this is the very best bike I EVER owned. Problem is that for some reason, though it worked fine before we moved, after the movers delivered it, neither shifter wants to do much. The front will still switch between two sprockets, but the back is not shifting at all. If I pull on the back cable I can cause it to switch gears as long as tension is maintained.

I am guessing a good place to start is the shifters, but after opening them up I see these are a bit complex, and to guess at what should be right is not my first wish. I can not access any tech diagrams on the Shimano site and can't find any Googling - can anyone offer an alternative (If I had the spare funds I would take it to a shop, but that is not an option)?


Have a look at www.parktool/repair and that should have a step by step diagram on how to set your gears up properly. If you follow it carefully you shouldnt have too many problems. If you do, give us a shout on here and I'll see what else I can do.

have fun riding

dave

Hi y'all!

The front will still switch between two sprockets, but the back is not shifting at all. If I pull on the back cable I can cause it to switch gears as long as tension is maintained.here's your hint -- your cable tension has been lost. tighten the rear shift cable.

check all your rear shift cable to make sure it's in place -- a lot of bikes have "interrupted cable", which means some sections of cable have no housing, and the pieces of housing plug into bits welded onto the frame. Check all of these to make sure none are out of place before tightening cable.