Classic & Vintage - Freewheel Cleaning

Can I toss an old freewheel in a can of gas to clean it up? Are the internals on these mostly metal?

Dont throw that freewheel into anything, much less gas. If you want to clean it up use mineral spirits and a brush, brushing the spirits all over it and between the cogs. Gas is highly flammable.

Throwing it in mineral spirits won't hurt, I wouldn't use gas.

How about a light weight oil?

I dunno, just wondering out loud.

If they're really old and gunked up, I slosh them around for a while in citrus degreaser to take care of the internal stuff, and use a fairly soft wire brush and rags to get the external stuff. I shake them dry thoroughly, then lay them out on the hearth in front of a warm woodstove for a day or two to make sure that all of the moisture is out of them. There are tools out there to inject grease into freewheels, but I lubricate them by oiling them, a few drops at a time, at the point where the stationary body intersects with the spinning cogs. Drip, spin, drip, spin ... you get it. You can tell when they're good and lubricated when the sharp "tickticktick" turns to a more muffled sound.

Gasoline ...uhhhh, no. It goes boom. It's carcinogenic. And if you use it for shop solvent, you've got a toxic disposal issue.

I generally just drip in a light penetrating oil while turning the ratchet. Keep going until you hear a distinctive muffling of the ratchet clicks. Dirty oil should emerge from the other side of the freewheel body.

I've cleaned several now with a *solvent* soak, in one of those robust plastic Rubbermaid food storage tubs with a tight-fitting top. Let soak a day, spin awhile and remove, filtering the *solvent* through a coffee filter, then repeat, until spinning no longer gets you gunk or particles out of the thing. Let air out a few days (no heat, now) and stink the house up good. Then spin in drops of oil until it won't take any more, let drain on rag/towel and spin some more. I try to keep the cogs themselves relatively free of oil in use (use ProLink Gold on the chain), and clean the freewheel superficially about once a week when riding regularly, or whenever it's been windy/wet.

*solvent* I've been using is kerosene, which others will pooh-pooh, but I, like General Melchett, will pooh-pooh the pooh-pooh, until I find something I think works better. I've had no luck with using Simple *color*, just because it doesn't seem to cut the grease well enough, and I am morally opposed to putting water and steel together when I can avoid it! Someone whose nick is etherhuffer has no call to complain about solvent.

I have a spray can of brake parts cleaner to get the nasty gunk off, then mineral spirits and a toothbrush for the rest

Last FW, I re-lubed with Case/IH Hy-tran ultra, but you big city types might have a time finding that.... :D

Ha! You guys are big chicken ****s! Gas and kerosene are not that far apart. Both are hydrocarbons but indeed gas is more flammable. Acetone is too harsh on plastic, and alcohol is not solvent enough. But thanks for the advice.

I take them apart, then soak the parts in lacquer thinner.

I drop them in my ultrasonic cleaner with some water/degreaser. If it has a bunch of thick gunk I take a plastic brush or flat screwdriver to scrap the gunk off. Once more through the ultrasonic, let air dry on a rag, and then oil/spin until clean stuff comes out the bottom. Most of the freewheels now look almost new.

There have been a number of discussions on Mechanics about best solvents. BF poster is a professional chemist, and he has posted a bunch of interesting facts about different solvents. Main conclusions I've come to from his and other chemists' postings are as follows.

1. Odorless mineral spirits is the ideal solvent because it (a) is fairly low in toxicity and (b) evaporates the quickest (good for keeping away rust, also).

2. Simple Green only works because of the polarity of water molecules. That is, it bonds to grease, and only goes away because it resists water. It's a pretty poor solvent. Beyond that, it's not 'green' at all if you just wash it down the drain--all that oily gunk and metal does no good for the sewage system.

I actually have a minor(BA) in chemistry so no problem on the chemistry, just didn't know the guts of the freewheel. This is a Voyageur 11.8 freewheel that is supposed to be Shimano. I bought a Shimano freewheel tool but its too small and has exterior splines. The hub will need a tool with internal splines. What am I looking for?

I just take mine apart and use dish-soap and a toothbrush. It's not any nastier than doing the dishes, and the freewheels work like new when you put them back together. The real-deal, full-on disassembly takes quite a commitment but the results are worth it. The half-ass way that works pretty well is to just remove the cogs and clean them up separately and hit the ratchet with a little pb blaster until you hear the sound change or the solvent coming out is the same color as the solvent going in. Taking them apart really is the most effective as well as the most ecologically friendly method but i think most people are afraid of trying it for whatever reason.

Just to throw my $00.02 in here; no doubt some people here have the option of using

compressed air to finish-off the cleaning. This works great with one exception:

DO NOT SPIN THE BEARINGS, as in allowing the sprocket-set to spin on the hub.

There is no lube (hopefully) left, and it will damage the bearing surfaces with the high rpm.


Regards,
J T

I find it funny that, with a minor in chemistry, you ask if gas is a good solvent, get a majority of NO replies, and then reject and criticize the respondents.
Sure, gasoline can do the job, but it's far from ideal. It's too dangerous. It's not about having big enough balls to use it. You probably know better of it than I, but gasoline's flash point is a fire hazard, it contains aromatics such as cancer causing benzene. Evaporates quickly, and potentially explosive. Plus a load of additives not necessary for degreasing bike parts.
Kerosene is a very good choice. Mineral spirits an even better choice being less 'oily' (as in fuel oil).
They are less volatile and evaporate slower. Kerosene is safe for rubber parts too.

A more mild, extended long-term soaking or storing can be done with ATF. It has high detergency and still offer lubricity. I soak chains, freewheels, derailleurs that I don't have immediate plans for.

Well, humor translates poorly on the internet. Indeed kerosene and mineral oil are less harsh, if that applies to the item being degreased. The issue here is the object being worked upon. My question was contingent upon whether or not there are plastic parts in a freewheel which could be harmed. It does not sound like older freewheels have plastic internals which would be harmed by the solvency of gasoline.

Modern gas can have alcohol or MTBE for pollution/octane boosting. Alcohol is actually useful as a penetrating agent. Note its use in chemical strippers based on methylene chloride. Methy and ethyl alcohol are both safe, the latter being in my nightly beer. The MTBE is not particularly nice stuff but actually a very close cousin to the stuff that has been in "409" cleaner for decades and oft used as a lacquer thinner for evaporation ***********. Its a great degreaser. Its soluable in water or other solvents. Modern gas surfactants are similar to Tide laundry detergent, usually with a large benzene ring attached to a long chain aliphatic hydrocarbon. Keeps the sludge suspended in the oil.

ATF is a great detergent/lube as you note. I have an RX 7 and ATF is one of the few items that can work to break free a stuck apex seal in a seized engine, if Marvel Mystery Oil doesn't work.

As for fear of benzene and toluene, those are indeed not nice to breathe. But as a chem lab tech doing quality assurance for some years, I am sure I have long ago been exposed to enough to kill me. Sure don't want folks to go buy any at Homer Despot however(still legal to get toluene) and start washing parts in it.

The best degreasers ever are carbon tetrachloride, now illegal, perchlorethylene(drycleaning fluid), 1,1,1 trichlorethylene or trichloroethane, the latter two used in vapor degreasers in metal fabrication(mag wheels being common). Breathe those a while and then have a beer and you can get "degreaser's rash'', which is not very pretty.

The uber solvent of all times is Freon TF. The trouble with Freon and trichloro compounds is that they kill the ozone and some will etch aluminum, being slightly acidic.

Most water based degreasers are surfactant based, and rinsing parts with water afterwards means rust unless you can dry the part, bearing spinning not being a good finish to that act.

Can I toss an old freewheel in a can of gas to clean it up? Are the internals on these mostly metal?

If you've never done it you should detail-strip a freewheel at least once in your wrenching career.
Top

To clean a mildly dirty freewheel, I remove the cogs from the body, clean the cogs, and replace. Takes 10 minutes, a chain whip and a bench vise.

To clean a really nasty freewheel I remove the cogs and then disassemble the body. The body lockring is usually left-hand threaded, but not on all freewheels so check by trying left first, then right. Some (Suntour Winners?) actually have the thread direction marked on the lock ring. I clean all the individual parts in mineral spirits and then reassemble with a lightweight grease. I generally reuse the old bearings because FW bearings (and races) never really carry a load when in use (that's where the "free" comes from, as in no-load pedaling or coasting) and seem to wear at a rate much slower than the teeth on the cogs. Takes me about 20 minutes and only requires a chain whip, bench vise, the proper FW removing tool, and a pin tool (usually used to set the BB adjustable cup). I just sold two Lambert FWs on eBay that I rebuilt. They are way smooth now.

As an addendum to my last post about rebuilding freewheels, I have these thoughts to offer.

Any decent solvent, if dribbled into the gap between the freewheel body inner and outer shells, will go in clean and come out dirty. That much is a given. But that doesn't mean that the bearings, bearing races, pawls and springs have been cleaned of all (or even any) dirt, debris, old lubricant, rust and general gunk. It also follows that any lubricant thin enough to be dribbled in will eventually (and probably rather quickly) run back out again and be deposited all over the rear end of your bicycle, leaving the bearings starved of lubricant and your rear wheel and drive side chain stay a mess.

The freewheel body must be disassembled, properly cleaned and relubricated with light grease in order to achieve maximum performance.

OK, this begs the obvious question: If rebuilding and repacking a freewheel's internals with the proper lubricant is so important why have millions of bicyclists ridden tens of millions of miles with dirty, poorly lubricated freewheels and yet suffered no catastrophic failures, careening off the road and tragically crashing into a pile of bent steel at the bottom of a cliff (or some such)? Because, frankly, a dirty freewheel a) doesn’t noticeably degrade bicycle performance at all and b) doesn’t wear particularly fast. All they do is spin freely under no load when you are not pedalling and lock up completely when you are pedaling. Basically, freewheels, unlike hubs, are low performance parts whose bearings never see a load of any kind. They are replaced because the cogs wear out or because the rider desires a different gearing range—not because the internals wear out. Freewheels are critically necessary to supply the rider with a range of gear ratios. That’s why rear gearing has gone from 1 to 10 cogs over the last 100 years (and front chain rings have gone from one to two or three). But light or heavy, dirty or clean, pretty or ugly, alloy or steel, 3-speed or 7-speed... they pretty much all do the same job. Free hubs and cassettes haven’t replaced freewheels because they do a better job at shifting, driving or whatever. They have replaced freewheels because they inherently weigh less and because they allow the drive side bearing to be much further outboard, thus protecting the rear axle from stress-induced breakage. And, yes, a freehub should be disassembled and packed with light grease too.

http://www.sheldonbrown.com/freewheels.html

I've never disassembled a freewheel. Soak in mineral spirits, spin, dip and flush now and then, let it dry. I use motor oil to lube (probably 10/50, whatever's around). Same with chains, motor oil, let em hang a day.

But I've only been doing this 35 years, what do I know...

Ideally, complete overhaul of the body, and while you're in there, optimizing the number of balls and adjust the races, will yield the most satisfying operation. But not everyone has the time, aptitude, tools, patience (or the eyesight) :D, to tear down a freewheel or freehub.
If one follows a periodic cleaning of the unit as most have posted, the internals will never get to the point where only a complete overhaul can resolve.
I've only come across one freewheel (a Suntour) that was so worn/neglected, with excessive play, that only an overhaul might save it. Instead, I recommended replacement to the owner.

... Gas and kerosene are not that far apart. ...

In fact, good old WD-40 is 50% mineral spirits, a close cousin of kerosene. Other ingredients include about 15% mineral oil, plus "inert ingredients," which a chemist friend to me include vanilla extract.

"I recommended replacement to the owner." QUOTE.

Should't that read "replacement OF the owner" ?

(LOL)

Regards,
J T

"I recommended replacement to the owner." QUOTE.

Shouldn't that read "replacement OF the owner." ?

(LOL)

Regards,
J T

As someone who uses kerosene, I feel compelled to defend it, relative to gasoline: they differ a lot in flash point (the lowest temperature at which the liquid forms an ignitable vapor). Gas is -40 C, while kerosene is 38-162 C. Quite a difference.

I always soak them in mineral spirits, brush between the cogs, etc., dry well, then lube them with Sturmey-Archer 3-speed oil, which seems to work quite well. I've never disassembled one... could be fun :eek:

One of my pet peeves is the use of registered trade-marks as generic names for a product, as in Band Aid for any bandage strip, Coke for any soft drink, or Freon for any refrigerant. Freon TF is Duponts trade-mark for trichlorofluoroethene. A chemist should know the difference.

Hey, thanks for all the comments folks. I got the layers of crud off of the cassette, and there is little gold plating left on the original Voyageur gears. This is one trashed out bike. The gear tips look ok, but barely. I ran some PB Blaster into the freehub, followed by some light oil and it sounds and feels quite quite good. But the wheelset is trash, the spokes heading into corrosion land. Not worth the work for me. Harris bike has 27" wheelsets with freewheels for 120 bucks or so, a much better deal in time, quality.

Same goes for the gears on the Super Maxy crankset. Uff da!

Waldowales, Freon TF is indeed trichlorofluoroethane, not an ethene, if I remember correctly. For the sake of folks here, that is getting down to minutiae. But I do agree that generic chemical names take the mystery out of products. My favorite is all the combos of trisodium phosphate and bleach sold as Miracle Whatever for home use. I have bleach and tsp and mix the stuff at home. All I lack is the small amount of colored tint that completes the 'miracle!'

As an addendum to my last post about rebuilding freewheels, I have these thoughts to offer.

Any decent solvent, if dribbled into the gap between the freewheel body inner and outer shells, will go in clean and come out dirty. That much is a given. But that doesn't mean that the bearings, bearing races, pawls and springs have been cleaned of all (or even any) dirt, debris, old lubricant, rust and general gunk. It also follows that any lubricant thin enough to be dribbled in will eventually (and probably rather quickly) run back out again and be deposited all over the rear end of your bicycle, leaving the bearings starved of lubricant and your rear wheel and drive side chain stay a mess.

The freewheel body must be disassembled, properly cleaned and relubricated with light grease in order to achieve maximum performance.

OK, this begs the obvious question: If rebuilding and repacking a freewheel's internals with the proper lubricant is so important why have millions of bicyclists ridden tens of millions of miles with dirty, poorly lubricated freewheels and yet suffered no catastrophic failures, careening off the road and tragically crashing into a pile of bent steel at the bottom of a cliff (or some such)? Because, frankly, a dirty freewheel a) doesn’t noticeably degrade bicycle performance at all and b) doesn’t wear particularly fast. All they do is spin freely under no load when you are not pedalling and lock up completely when you are pedaling. Basically, freewheels, unlike hubs, are low performance parts whose bearings never see a load of any kind. They are replaced because the cogs wear out or because the rider desires a different gearing range—not because the internals wear out. Freewheels are critically necessary to supply the rider with a range of gear ratios. That’s why rear gearing has gone from 1 to 10 cogs over the last 100 years (and front chain rings have gone from one to two or three). But light or heavy, dirty or clean, pretty or ugly, alloy or steel, 3-speed or 7-speed... they pretty much all do the same job. Free hubs and cassettes haven’t replaced freewheels because they do a better job at shifting, driving or whatever. They have replaced freewheels because they inherently weigh less and because they allow the drive side bearing to be much further outboard, thus protecting the rear axle from stress-induced breakage. And, yes, a freehub should be disassembled and packed with light grease too.


Well said!