gleplae

Hi,

My chain recently broke and I replaced it with a new one and also installed a new rear derailleur. The problem I am having is that the chain skips when I shift into the three smallest sprockets on my freewheel. I have also noticed that the skipping gets worse when I shift into the smallest sprocket and when I shft onto the fourth sprocket and above the skipping goes away.

SpokesInMyPoop

hmm... sounds like you need a new freewheel. Are the cogs on the freewheel worn out? I've heard that it's generally good practice to install a new cassette/freewheel when you change out a chain. I know it's worked for me on my ole bike.

brokenrobot

Yep, very likely time for a new freewheel.

cuda2k

I've been experiencing a little bit of this myself with my freewheel when I put on a new chain (gave the other one away when selling a frame). The Freewheel only has maybe 7-800 miles max on it but guess that's enough to cause periodic chain skip, esp in the middle gears where I spent most of my time. I picked up a 7speed freewheel (Shimano HG) on ebay for 19.50 delivered.

koine2002

If those are the gears you used the most, then it's most likely that you will need a new freewheel. As a chain "stretches" (when the innards wear and make the chain longer), it wears on the freewheel and they are meshed together. When you replace that chain, the freewheel (at least your favorite cogs) don't mesh with the new chain and skipping occurs. If you replace your chains before the stretch is too bad, your freewheel will last a whole lot longer. You can go here to see all that you'd ever want to know about this, and more.

San Rensho 

Probably worn cogs but check to make sure you don't have a tight link in the new chain. Twist the derailleur so the chain is slack and backpedal. A tight link will show up as a kink in the chain and can also be seen and heard as it goes through the der.

NFields

Have you micro adjusted the new derailler yet? Mine skipped the same and was fixed by using the barrel adjuster.

NFields

HillRider

It may be derailleur adjustment or a tight chain link but the smart money says it's worn cogs. The fact the skipping occurs only on the smallest few cogs makes this almost a certainty. Time for a new freewheel.

You could in theory replace only the worn cogs but individual freewheel cogs are very difficult to find these days and, when available, are priced so high that a complete new freewheel is more cost effective.

gleplae

Well I guess my next question is what type of freewheel can I install on my bike the one I have now is a shimano hyperglide 400 kfgfom, I looked on ebay and saw af ew different types but I am not sure if they are compatible with my hub.

roccobike

+1 I wouldn't be so fast to change that freewheel. I've had three bikes skip after installation of a new chain. Only once was the cassette/freewheel at fault.
Did you replace the chain with a like for like or did you change brands or within the same brand, a different style/grade? I tried a SRAM PC on a six speed freewheel. Although they advertise it will work, it did not.
Did you micro adjust the deraileur as NFields suggested? You installed a new deraileur, I'm assuming the new deraileur requires the same chain length and that you've checked the chain length to assure it's correct.
I mention these items because changing the cassette/freewheel, will not fix the skip problem if it is not the source of the problem.

Ronin

If this problem stared right when you replaced the chain then more than likely you got the wrong chain. A six speed chain will skip like hell on a eighter or niner cassette.Assuming your derailluer adjustment is ok. Good luck. If you need help adjusting the derailluer see sheldonbrown.com for more help.

koine2002

Assuming you have a threadon freewheel, they are pretty much interchangeable between brands when it comes to the hubs. Just to be sure that the spacing works with your indexing (assuming you have index shifting), I would get another Shimano freewheel, a SunRace or a SRAM. If you're running a cassette, the same brands will work. Sheldon Brown has a good article on how to tell the difference.