Freewheel Maintenance

fabieville

100 W
Joined
Jul 15, 2012
Messages
114
What method(s) should be implement to keep your single speed freewheel in perfect working condition?
I realize that sometimes the "dog" in mines sometimes slip and I have to flush out the freewheel with Double D40 to get it working again.
I normally use the Double D40 to flush it out and then I lubricate it with Tri-Flow Superior Lubricant P.T.F.E oil as I saw on the net that someone suggested.

I do a daily commute on my ebike of approx. 40 miles each day. Can you tell me how often I should flush out the freewheel and lubricate it with oil to ensure proper working conditions at all times?
Would once per 2 weeks ok or what do you suggest?
Also would proper maintenance of the freewheel prevent it from never have to change? Reason why I ask is because mines is a mid drive e-bike so therefore all I do is change the chainrings sprockets that are connected to the freewheel whenever they are rub down too much.
 
Most freewheels are made with sealed bearings and can’t really be serviced.
When you start needing flushing them with lubricant spray, it is usually because they soon need replacement.

Freewheels that are serviceable can be opened with a spanner, to access the bearing crown. With those, you can clean and grease them, and replace the bearings when needed.
 
Whatever lube you use on your chain can be applied to your freewheel occasionally to keep it running smoothly. Normally, any freewheel that's used regularly will wear out its sprocket teeth long before it wears out its ratchet teeth or pawls.

Make sure you have good chainline and you're not applying force (which is different from power) far in excess of what the freewheel was designed to tolerate. Ordinary single freewheels are cheap enough that it's a good idea to replace them anytime they misbehave.
 
Where I ride off road, cheap screw on freewheel pawls get full of sand. Lying the bike on its side, I pour motor oil in it and let it rinse the sand out the other side. You can use a lighter oil too, like zoom, or 3 in 1, sewing machine oil, etc. Motor oil is cheapest. I just fill an old zoom oil container with 10-30 my car uses.

God awful mess of course, as the freewheel continues to puke gritty oil for several rides. I just rinse off the rim after those first rides. WD 40 would be only to free up a dirt packed, rust filled, old junk freewheel.

On the street bikes, I use white lightning, or other similar clean chain lube. Its cleaner in there, but I still do the same thing, over lube, and the excess takes some grit out the back side of the thing.

The axle bearing, lubes with grease like normal on a cheap bike wheel. Take the axle nuts off, and the bearing nut, and stuff the axle with grease. A motor wheel will have sealed bearings.
 
I have no idea what Double D 40 is, but it sounds like the title of a movie I would watch 15 minutes at a time. :twisted:

If I can get the freewheel apart, I'll dismantle it, soak it overnight in ATF, and then repack the bearings and pawls with Boat trailer grease. Boat trailer grease can help bearings to survive even if they get water in them.

If I can't dismantle it, I'll pretend it's a ninja star and see if I can make it stick in the fence. If it sticks, it has a use and I'll leave it there as a reminder of my awesomness. If I can't make it stick, then it a useless ninja star, and it goes in the trash. My time is worth more than the replacement cost of those things, so there's no point in putting it back on a bike. Rebuildable replacements can be had for less than $3.
 
Drunkskunk said:
I have no idea what Double D 40 is, but it sounds like the title of a movie I would watch 15 minutes at a time. :twisted:

Just do a Google image search for Double D 40. :wink:

I had one fail when the grease got sticky and the pawls didn't engage fully. Almost hurt myself when it slipped under load. It was good after just cleaning and re-greasing. It was the kind that comes apart.

If sand is a problem, it might be better to use dry lube.
 
MadRhino said:
Most freewheels are made with sealed bearings and can’t really be serviced.

I haven't seen any in the stuff I've gotten (used) that are sealed bearings--they're all loose balls inside. Both singlespeed and multispeed stuff. Which brand(s) do you use? (so I can keep an eye out for those, as they'd be a lot easier to work on if I had to, and less likely to have to).

However, I've seen some of the cassette hubs that have sealed bearings in them.


FWIW, I only use grease on the bearing races, and only just enough to cause the bearings to stick to them while I reassemble the freewheel body, cuz I've had too many stuck pawls from the grease hardening.
 
MadRhino said:
Most freewheels that I have are White ind. single. Very easy to service.

They had better be! You can buy at least ten ACS Main Drive freewheels at my shop for the price of a single White Industries freewheel. I don't think I could ever get enough life out of the sprocket teeth to make one cost-effective.
 
flat tire said:
You need to use grease.

I'm not sure what you're talking about, but every freewheel I've ever come across in 30 years of working on bikes was oil lubricated.

Grease causes pawls to stick down and the freewheel to malfunction.

It's not the worst idea to grease the bearing balls, separately from the pawls, but keep in mind that freewheel bearings are very light duty, because they only turn when there's no load on them. (Unless you use them in an ineptly designed freewheeling crank.)
 
As soon as you build a hub motor bike with too much speed to pedal, the freewheel bearings are spinning most of the time, and heated by the motor contact. Freewheel failures are more frequent and it is even worse riding dirt.

A good freewheel is not luxury then, when you get tired taking them off.

Anyway, this is true with many other components. When you turn a bike into a motor bike, quality components are a good investment for reliability and maintenance as well.
 
MadRhino said:
As soon as you build a hub motor bike with too much speed to pedal, the freewheel bearings are spinning most of the time, and heated by the motor contact.

But you understand that there is still no radial or axial load on the bearings while they turn, unless you've overtightened the chain? I don't see how foreseeable e-bike speeds and temperatures change the prognosis for bearing life.
 
I can see them grinding to dust if you don't flush the sand out often enough though. That's why I pour oil through them on the dirt bikes, messy as that is.

Far from proper bike maintenance, but on the dirt bikes that rarely pedal, and use cheap freewheels, it works for me.
 
fechter said:
I had one fail when the grease got sticky and the pawls didn't engage fully. Almost hurt myself when it slipped under load. It was good after just cleaning and re-greasing. It was the kind that comes apart.
i'm not sure if we're talking about freewheels inside a geared hub motor, or about the freewheels mounted to the wheel.
last week my MAC's freewheel started to slip. horrible screeching sound. this was expected, as the motor sees 2.5kW+ all the time, so something has to give.
the question for me: normally i would replace it with a new one, but it cleaning and re-greasing will make it work again i would try that. any chances of success?
 
dogman dan said:
I can see them grinding to dust if you don't flush the sand out often enough though. That's why I pour oil through them on the dirt bikes, messy as that is.

Here, the dry and gritty freewheels I flush out are full of rust, not dust. I wash out most of the crud with solvent, then squirt in enough Tri-Flow to quiet them down a bit. If I let one of mine get that bad, I'd throw it away.

It's funny, the differences that environment makes. Back in Seattle, it was normal for an all-weather commuter to grind up a pair of rims per year. Here in Austin, I very rarely see rims with worn-out sidewalls. But Seattle is built on granite and Austin on limestone. Seattle's style of rain gets everything dirty, and Austin's style of rain washes it clean.
 
And here in Phoenix, the extremely fine flinty(?) dust tends to grind things away if you lubricate them with anything that gets sticky--I've had better luck with zero lubrication than with just about any dry or wet lube or grease on anything I can't seal against dust.
 
True enough here too. The sand I'm talking about comes straight from granite peaks 9000 ft tall, about 4 miles from my house. Its like sandpaper grit, so you either flush it out regular, or you can just go dry. On the street bikes, its not so bad that you can't water flush, then lube with white lightning or similar stuff. Not much risk of water flushing causing rust, when the relative humidity is around 1%. I won't water flush when its rainy though.

On the dirt bikes, I just flush em out with oil every 10-20 rides or so, about monthly when I'm riding a lot. The chain just gets white lightning on both kinds of bikes. Oil just attracts too much grit. But on the freewheel I just oil flush it, and run with a filthy rear wheel all the time. Only if I go mudding does the dirt bike get washed, but I don't water the freewheel. just the mud caked on the frame and tires.
 
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