robertj298 

Recently I've noticed that the chain loosens and tightens on it's own
but only when it's coasting. It can do this 3 or 4 times in a row. It's always
ran perfect in the past. I did change to a newer freewheel and chain a couple
years ago which made shifting much smoother and quieter. It's running
Shimano 105 components.

robertj298 

After reading and testing further I've determined it is the freewheel. Whats
strange is I changed to a newer freewheel and chain a couple years ago
and it vastly improved shifting smoothness and made it a lot quieter. I have
put very few miles on it since then.

icemilkcoffee 

What do you mean by the chain loosening and tightening on its own? How are you seeing it?

robertj298 

While coasting the top of the chain loosens up.

robertj298 

I put the bike on a stand. Put it in the highest gear. Turned the rear wheel
with my hand and felt the freewheel. The freewheel has a tenancy to spin
clockwise while doing this causing the top of the chain to loosen

icemilkcoffee 

Mmmm. sounds like the freewheel has a lot of friction. Some of these freewheels have been sitting on a shelf for ages.

HillRider

Lay the bike on its side, freewheel side up. Spin the rear wheel and dribble light oil (Tri-Flow is a good choice) into the seam where the inner core and outer shell of the freewheel meet. That should lubricate the bearings and flush out any hardened old lube.

Andrew R Stewart 

Other causes of FW lack of spinning/coasting is stuff wedged behind it. Sometimes it can be the spoke guard rubbing on the FW's back side. But this should be able to be seen and internal rust or gummy lube not so. Andy

robertj298 

Took your advice only I took the wheel off the bike squirted WD40 into the seam and spun
it over and over then squirted some T9 oil in it and it works like a charm again.

Andrew R Stewart 

T9 is not oil or was intended to be a lube. It is a wax designed to prevent Al corrosion during aircraft parts storage. Andy

robertj298 

Says on the bottle it is a bicycle lubricant.

Pop N Wood

No, WD40 is also a solvent that dissolves grease and washes it out. Your freewheel will quickly wear out from a lack of grease. I once destroyed a set of pedals "oiling" them with WD40 before.

Do the triflow trick that AndrewRStewart suggested.

robertj298 

I know WD40 is a solvent. Is that not what you would use to flush out the old gunk and then lubricant out afterward?

easyupbug 

In our experience after flushing with WD the bearings have no grease and T-9 is a wax not a grease, which while fine for some time in an open chain is far from ideal for bearings and races over the long term.

rosefarts

That bike probably came with Biopace chainrings. I think that constantly changing chain tension has to have an effect on freewheel.

FWIW, on my wife's Ironman, I switched to 50/38 round rings and a 13-28 freewheel. She's not a serious rider but it certainly gives her better options than the 52/42 and 13-24 it came with.

Andrew R Stewart 

Given enough of it, water is a lube... So wax can be used to lube stuff. As can soap. But both make a lousy long term one and wax being a solid will flake and get pushed away from the contact points. Of which in a FW there are many.

I will agree that wax is far better then gummy oil based lubes. Just it's only a stop gap one at best. My point was to have people not think waxing ball bearings is the better method to lube them. After over 100 years of bikes using ball bearings this has been pretty well figured out way long ago. Andy

oldbobcat

That's your freewheel/freehub body binding up with dirt and dried-out lubricant. If it's a freewheel, shoot a few drops of thin oil into the bearings. Even better, if the freewheel and chain are as old as the bike, replace them. If it's a freehub, you're looking at a hub overhaul. Something I don't recommend for beginners.

oldbobcat

WD-40 is an excellent solvent. Be sure to flush and dry before applying the lubricant of your choice.

easyupbug 

I have heard this about WD but struggle as with my experience with it is just some OMS with a little oil kicker for some reason. At our HD WD is $22 and OMS $8 a gal for the same job.

oldbobcat

I didn't say use it by the gallon. It's not my favorite, by any means, but most households have a can of it somewhere and it works. Especially for applications that require an aerosol blast.

ShannonM

Phil Wood Tenacious Oil is the absolute, no doubts, #1 bestest-ever lubricant for freewheels.

Drip in slowly while spinning the freewheel. Wipe off excess, including between the back of the freewheel and the hub flange. For maximum points, remove the freewheel and lube from both sides.

F(un) Fact: "Tenacious D" was named after Tenacious Oil, because it's that awesome.

--Shannon