[jimigunne]

Its a WalMart. 26in 10 speed mountain bike. The rear shifter cable is moving free between right twist-grip shifter and derailleur---but wont shift more than one cog. I pulled every bit of slack out of cable at derailleur. But if I push on shift cable where it is exposed along upper bike frame itwill shift easily through all five cogs. How do I adjust or fix the twist-grip shifter?
Sorry I don't have make/model off the top of my head. Its a lot like Mongoose but isn't

[davereo]

Make sure the derailuer is all the way over on the smallest sprocket. Loosen the srew attaching the cable to the deraileur. Make sure the grip shift is on 5. Screw the adjuster knob that the cable sits in all the way in. You should have at least one adjuster it will be right where the cable housing either enters the shifter or derailuer. Pull the slack out of your cable at the deraileur and tighten the clamp screw.

You should now be fairly close to all is working. Try shifting to 4 and pedal the bike. If the chain dose not move up one sprocket adjust one of the barrel adjusters outward 1/4 of a turn pedal bike if it dose not shift repeat this process of 1/4 turn at a time until it shifts up. Once it shifts you should be perfect.

Check on you tube. Plenty of videos on how to do this.

[superj]

yah, its super easy to do but you have to make sure the chain is on the smallest gear and your adjuster at the shifter is all the way tightened down. just don;t forget those two parts and you'll be good

[SG78]

YouTube

YouTube

This is the YT video that helped me get my rear derailleur going. It's pretty well along the lines of davereo's comment.

[jimigunne]

I have a much cheaper and simpler derailleur that has no limit screw adjustments. Also, It doesn't have the lever-type shifter, it is a shifter that you rotate like a throttle. There are no numbers visible any longer in the little window (creating confusion). So we need to know if you start out with this handlebar shifter in max slack or max tension position. Would it be max slack, since the derailleur is on the smallest/high gear when the cable is slack? The other difference is that there are *two* barrel adjusters--- one at handlebar shifter, and one at the derailleur end also. Am not sure if we need to start out initially with BOTH adjusters screwed in full clockwise or not? The only problem we are fighting is that the handlebar shifter doesn't vary the tension enough to be able to select all the gears/cogs. By making adjustments, we have only succeeded in getting derailleur to work on the lower 2 or 3 cogs, or the higher 2 or 3 cogs...but not all. There is absolutely nothing wrong with the rear derailleur, since pushing on the cable, as I said, at the first place where the cable is exposed going back from the handlebars will make it run through all the gears, no problem! When we stop pusing with finger, it shifts back to high/smallest gear! thanks, all, Jim

[i12ride]

max slack and any adjusters adjusted into der or shifter as much as they will go then pull cable tight, tighten lock screw and adj adjuster out until it shifts right each click.