Chain intermittently slips in all gears. Is there an adjustment

Firstly ensure the derailleur is in good condition and not bent so the chain is running perfectly in line with the sprockets. Ensure the stop screws limiting the extent of the travel of the derailleur are set correctly to prevent travel beyond the first and last sprocket.

A badly worn chain could need shortening or replacing in order to provide the correct chain tension or a loose chain could be a matter of a derailleur that hasn't seen the oil can for a while and is not tensioning the chain correctly.
If the bike has been involved in an accident the rear forks could perhaps need some adjustment so a straight edge laid alongside the main chain-wheel coincides approximately with the middle of the rear sprocket cluster.

At this stage it is also wise to ensure the gear cable is in A1 condition, smooth operating and properly oiled with no internal frayed strands causing problems.

If your gear selectors are of the modern style with detents the gear cable needs adjusting so the centre of each detent at the gear selector positions the derailleur precisely below the selected sprocket. Once this is done if everything else mentioned above is ok the gears should now operate smoothly and positively.

If adjustment doesn't work then the problem is likely to be with the basic requirements above.
Good luck!

tighten the chain and straighten the back tyre

Hi michaelcook1....
Sounds like you need to adjust your derailer on the back of the bike, it may be out of adjustment and causing the chain to slip.
Please take time to rate me

http://www.parktool.com/blog/repair-help/rear-derailler-adjustments-derailleur

You might also evaluate the chain...

http://sheldonbrown.com/chains.html

http://www.parktool.com/blog/repair-help/categories/derailleur-systems

Or you might have chain, drive train wear.

http://bicycletutor.com/chain-wear/

Evaluate what is really happening. The chain has to engage in the teeth both front and rear or it will seem to slip.

If your drive train is original, high-mileage and/or under-maintained you probably have worn gears and a 'stretched' chain.

http://sheldonbrown.com/chains.html

http://bicycletutor.com/chain-wear/


Total replacement is the only way to resolve worn

Incorrect rear derailleur adjustment will allow unintentional shifting between adjacent gears which sometimes feels like skipping.

http://www.parktool.com/blog/repair-help/rear-derailler-adjustments-derailleur

If you mean that your gears are slipping by means of the chain improperly engaging or riding along the walls of the cassettes outer gears, you can adjust the rear derailleur by means of a few tools. You can control how far in and out the derailleur moves by adjusting the two limit screws with either a proper fitting allen wrench or a small phillips head screwdriver. This won't have any affect on the inside gears but if it slips on the outer-most gear, it may help. You can then adjust the cable pull by hand on the adjusting knarp if present on the derailleur. It is the little (sometimes plastic shrouded) adjusting mechanism which the cable housing seats itself in. It is found directly on the derailleur and commonly on the shifter being used with the derailleur. You can rotate the knarp clockwise to loosen the cable or counter-clockwise to tighten. If the knarp has been threaded all the way in or too far out, you can return it to its original position and tighten or loosen the shifter cable manually using either a 5mm allen wrench, a 9mm box end wrench, or a specialty tool. Depending on the positioning of the derailleur and its design, tightening or loosening the cable will affect the position at which it is placed for each related gear. With a little bit of time and examining, you can hopefully figure out the most effective setting which would hopefully allow the derailleur to engage each individual gear without hesitation. To tell wether you adjusted it properly, follow these guidelines. 1, Make sure each gear being engaged is reflected on the position of the shifter. 2, When shifting gears by hand, the chain should not drop below the selected gear nor should it hesitate to move into the selected gear from its previous gear. 3, Check the limit screws position on the derailleur and make sure it is adjusted so your low and high gears are engaged without the chain slipping past the low or high gear, and slipping of the cassette. 4, When tuning the rear derailleur, make sure you account for the change in the chains travel path due to front chainwheel shifts.

- If the derailleur is not an issue, and you attempted to adjust it with similar results afterwards, look over the drivetrain of the bike closely while it is in motion and try to see the exact component that seems to be the source of the problem. I will be happy to dig deeper into this problem if you wish to ask another question regarding this issue. Good luck.

okay lets ask why it broke did it get jammed?was it worn?is your front crankset or rear gearset loose with play in it?does the chain make a clicking while pedalling hard? first and last require a replacement chain because it broke for a reason.if your drive gears are loose then you will have to adjust/repair them also checking adjustment on the derailuers should be checked.
hope this helps

You may have knocked the gear derailleur when fixing and re-fitting the rear wheel. This can knock the derailleur out of whack slightly and will need proper adjusting by your local bike shop.

This could be the hub assembly slipping I would replace this assembly and the pedal chains call National Gym Supply @ 800-496-7278 and get pricing for the hub assembly and step chain ( L & R )