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Discussion Starter · #1 ·
My friend bought a 2001 schwinn moab in mint condition.However the rear derailleur shifter will not shift from 1st thru 4th speeds.These are 8 spd acera model shifters.
Is their a repair possible?
If not what is a decent lo budget replacement model.I am talking about 10-40$ in the budget...Also what is straight cable shot?And is their incompatibility issues regarding replacemnt shifters....Will buy new or used..

Thanks
 

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Old man on a bike
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Could be a few things going on but hard to tell from your description. What exactly happens when you try to shift between those four cogs? Don't know what you mean by straight cable shot at all. As long as you use Shimano (or SRAM Attack series) 8-speed shifters you should be fine should they need replacement (and there's no reason yet to think they need replacement yet). Your problem may lie in adjustment or alignment of the derailleur, sticky cables/housing or old shifter grease needing flushing out...
 

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Discussion Starter · #3 ·
you can shift from 8-7-6-5 but then it just jams...you cant advance anymore...On this shifter you have 2 levers.One that moves the gear and the other that seems to be a clutch?On my mtb i just shift into gear with one lever on the pod.
 

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Old man on a bike
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That description doesn't help a lot either. If you have a trigger type shifter, one lever moves the derailleur in one direction, the other lever moves the derailleur in the opposite direction. I have no idea which specific models either of you have, the model number (not just name) would be helpful. What happens on the dual lever setup when you try to shift to the cogs that aren't cooperating? Does the lever move and ratchet but nothing happens or does the lever just push through when it should be ratcheting?
 

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Discussion Starter · #5 ·
okay,

i figured out that one lever is for shifting up and the other down...the problem is when youre trying to shift from 5th to 4th it wont extend any further...and i dont see how it could either it is already pretty extended at 5th i guess their is too much slack between each gear..like it seems you have to push the lever too far as it is to go from one gear to the next and then there is no more space to go further...this is basically what im trying to say...so does that sound like i have to make the spacing between shifts much more close and do i adjust that by messing with the shifter cable?shimano acera 8spd thats all i know....
 

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Old man on a bike
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dsq said:
okay,

i figured out that one lever is for shifting up and the other down...the problem is when youre trying to shift from 5th to 4th it wont extend any further...and i dont see how it could either it is already pretty extended at 5th i guess their is too much slack between each gear..like it seems you have to push the lever too far as it is to go from one gear to the next and then there is no more space to go further...this is basically what im trying to say...so does that sound like i have to make the spacing between shifts much more close and do i adjust that by messing with the shifter cable?shimano acera 8spd thats all i know....
Try this http://parktool.com/repair/readhowto.asp?id=64. Model numbers are usually stamped somewhere on the lever assembly (a number like the ones shown here on the techdocs.shimano.com site http://techdocs.shimano.com/techdoc...older_id=2534374302051137&bmUID=1231389990285
 

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Sounds like you may have your low (L) limit screw is not adjusted correctly on your rear derailleur. Try turning the screw counter clockwise a quarter turn at a time and see if this helps. If that is the problem, just make sure you keep it set so it can't shift PAST gear #1 (and into the spokes)
 

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Dirt Deviant
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those acera shifters gum up after about 5-10 years. You can most likely flush them with some degreaser or wd40 and bring em back to life. I've fixed several sets of aceras that way.
 

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As said, manually try to shift to the gears to see if maybe somehow the High/Low screws need adjusting - if it will move manually then doubtfull it's the adjustment screws. Open up the shifter and thoroughly spray it out with WD40 while actuating it - might take a little time doing this if it's really gummed up. If the bike is that old also check that the cables are good - both inner and outer.
 

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If ypou do the cmpressed air make sure you know hwo to put everything back together again, as the parts in there are generally not heavy and can easily be blown out - small springs etc. - but not a bad idea, but bad if you're not to mechanically inclined.

zarr said:
I was thinking blowing some compressed air through it along with the WD-40 cleaning might help too.
 

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Discussion Starter · #14 ·
I want to thank you all for the suggestions.
I moved the derailleur by hand and saw that it wasnt jammed.
I then adjusted the pair of screws that are close together on the derailleur but nothing happened.I then adjusted the single screw above those 2 and the chain moved up to the low gear sprockets...It doesnt seem like its stayiing in place but at least i know im on the right track.
Also the front derail wont get chain on the big chain ring.I tried the h/l screws there but no luck.

btw,It was 2 bike shops that recommended new shifters without even bothering to check the derail adjustments.My friend doesnt know jack about bikes so maybe they saw hin as a sucker?
 

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Glad we managed to point you in the right diredtion, now go visit the Park Tools web site and learn how to properly adjust your derailleurs and work on everything else on your bike.
 

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This is a copy paste from another thread I posted in from a while back. All the info applies to your shifters. Read through this and you should be on the right track.

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I've seen this a hundred times. What happens (this is my theory) is that after about a period of 5-10 years the grease inside of the shifter turns into a cake batter like substance.....and there is a very fine spring inside the shifter that controls the indexing. The dried up grease holds this spring in the open position. After a little while it will slowly return to the closed position and you will be able to shift again. At least you will be able to shift once, then the spring returns to the open position and the process starts over again.

It actually really easy to fix.
There are a few ways I have done it.
First way was to remove the shifter cover on the bottom side using a small phillips screwdriver.
Then I used an old toothbrush and dish soap and scrubbed the whole inner workings.
Work the shifter until it starts to grab.
Rinse with warm water and repeat until it starts indexing properly.
Then relube the inner parts with a white plastic compatible grease. Lithium grease works good.

OK, thats the hard way.

Now the easier way.
Get a spray can of Tri_Flow
Open the bottom of the shifter as described above.
Spray a blast of about 15 seconds all over the inside. Work the shift levers in both directions.
Spray another blast.
And repeat all above until it indexes.

Really all you need to do is breakdown the old grease and relube it and it will work 100%
I've never not been able to repair shifters using these methods. Even the super old 7spd sis shifters that wouldn't even get a single click when you hit the button.

I suppose you could use simple green, or just about any kind of soap or other degreaser that won't harm the plastic and it will work too.

I've also had good results with WD-40, since it is actually a better degreaser than it is a lubricant.

Also, Finish Line Citrus Degreaser works great. Stay away from the speed degreasers like Clean Streak and the like since they will attack the plastic.

If you can't find a proper grease to use, just lube up the internal gears with triflow or something. You may have to lube them often though if you don't replace that old grease with new grease.

You can do all of this with the shifter on the bike, but it is much easier if you remove them. Also, it is way easier if the cables are removed from the shifter as well.

Its a good time to do a cable swap and full tune.
-----------------------------------------------------------------------

More info in this thread.......
http://forums.mtbr.com/showthread.php?t=449406
 

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Discussion Starter · #17 ·
yes,spraying wd 40 did the trick.
I blasted the shifters several times and now they index and ratchet properly.
The only thing left to figure out is how to get the front derailleur to move the chain on to the big chain ring.
 

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Have you even bothered to go to the Park Tool site and look around like suggested? Somehow I think not, because if you had you would have found the answer - which BTW is a very simple one - and have that sorted already.

dsq said:
yes,spraying wd 40 did the trick.
I blasted the shifters several times and now they index and ratchet properly.
The only thing left to figure out is how to get the front derailleur to move the chain on to the big chain ring.
 
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