m2005

I tried turning the B tension all the way in and all the way out but it didn't even move anything. Maybe my b tension doesn't work? I'm super new.

hueyhoolihan

looks like the cage is too short. may be able to fiddle with the b screw if the frame has one.

m2005

I'm sorry, where would the b screw be on the frame?

hueyhoolihan

if present, it will be on the derailleur just below the attachment bolt. it pushes against a boss, if present, on the dropout that is just below the RD mounting threads. it screws in and out and moves the whole RD forward or back. sometimes it can give it little extra room between the jockey pulley and the rear cogs.

in essence it's a way of making minute adjustments between the relationship between the frame and the RD, in hopes, i guess, of improving shifting. it has lost some of it's significance, in my eyes at least, in recent years with all of the technological advancements in shifting design.

fietsbob

a spacer between the freewheel and that big pie plate?

Or maybe a smaller plastic spoke protector behind the freewheel, instead of the big steel one will quiet things down .

spdracr39

Mine did this and the chain was completely worn out. The lack of tension caused it to be so far out that the b adjuster wouldn't do any good.

Bill Kapaun

Do you have the same problem using the largest cog and all your chain rings?
Ditto smallest cog........?
How many rings?

With the chain on the largest cog and chain ring, insert 2 skinny screw drivers or similar about 4" apart through the chain links.
Squeeze them together, keeping them parallel.
How many "excess" links can you make?

choteau

I think you should read Sheldon Brown's Articles about Gears and Drivetrains he covered almost everything in an article or two.

hueyhoolihan

sorry, i assumed your problem was that the derailleur was making an unacceptable amount of noise when in the largest cog. and i meant to say the the derailleur may not be able to handle a cog that large.

krobinson103

Sometimes if the difference is small enough a slightly shorter chain can fix the problem. Though you need to be careful. Too short is just as bad as too long. The easiest way if its really not working is just to get a derailler with a longer cage.

Bezalel

Why isn't the axle fully seated in the dropouts?

The pic looks like a 28t cog, matching the capacity of the RX100.

hueyhoolihan

that bike, which is, i think, much older than the derailleur (at least the 5 speed freewheel is), probably came with that metal filler in the dropout. it prevents the wheel from engaging further. and it could be the reason the early 90's 1991 vintage rx100 that, i agree, has a 28t cog capacity, doesn't allow enough clearance between the jockey wheel and the largest cog, which is i THINK what this thread is addressing.

i didn't notice that dropout filler until it was mentioned, but i would suggest that the OP remove it and shove the wheel all the way back and see what that does. there may be one on the other side too, BTW.

Grand Bois

That's a French-style axle spacer and I've been looking everywhere for a pair.

Looigi

What ring is the chain on in the pix? If it's the big ring, the chain is too long. Shortening it may pulley, cog clearance.

cyccommute 

All ya all are missing the point with the exception of fietsbob. m2005's derailer is grinding against the spoke protector when he is in low gear. The lower limit screw could be adjusted to move the derailer outboard a bit if the pie plate protector is straight. Or he could remove the spoke protector (it's also known as a "dork disc", m2005) and be a whole lot faster, 'cause that thing weighs about 3 metric tons!

Metacortex

There is a pair of Huret Ref. 849 Alignment stops listed here: Vintage Axle Stop for Campy Style Drop Outs NOS | eBay

Grand Bois

That was pointed out to me before. It would cost me $23.98 for a pair. That's outrageous, but thank you anyway!