The Thin Man 

I follow a clever, local bike shop in Corvallis, Oregon. They posted about a J.A. Stein tool I hadn't seen before. Here are their comments/pictures:

We do have a few Stein tools, including a couple of freewheel injectors. When the internals of a freewheel get gummed up, most people don't find it worth their time to rebuild the part, which has dozens of tiny ball bearings to repack, assuming you can get it apart in the first place.
The injector pushes grease through the entire freewheel, lubing the bearings and the pawls in one shot. The downside is that heavy grease is great for the bearings, but can be a little stiff for the pawls. I usually add a tiny bit of lighter lube to the mix to find a happy compromise.
It's a satisfying tool to use, partly because it recovers an otherwise doomed part, but mostly because like a good nose blow it clears out nasty, unwanted buildup. You start by drizzling some solvent like WD-40 through the freewheel, then you attach the injector, and you push grease through until it comes out clean.







I'm into this little gadget and it looks like it works pretty well.

Who out there has one and what do you think?

Also, if you have one, I am also curious about if you also add a lighter grease since the zerks only really accept the heavy stuff.

merziac

No pics for me

tricky 

Weird. Pics work for me.

brandon98

It looks like an interesting tool for 30 years ago when freewheels were far more common (at least in the US among "serious" riders). It's definitely a specialty shop tool as most of us collectors and hobby wrenches are far too cheap to buy such a tool. But, I have to admit, that if I owned any freewheel bikes, I'd be tempted....

pastorbobnlnh 

IMO, I'd never use one. It really is the most improper way to service a freewheel. It is even worse than the "flush and dribble" method which is an okay short term fix. Also, what an incredible waste of grease!

Why? Because a freewheel is not meant to have the cavity in which the pawl recesses, or the ratchet teeth flooded with grease. Grease is sticky. Grease takes up space. Would you want your pawls to stick in the closed position? Or not be able to disengage from the ratchet teeth?

The LBS is smart to add a bit of oil to thin the grease in order to keep the above from happening, but why not service the freewheel appropriately in the first place? This is the only way to inspect for bad bearings, pawls, corrosion, bad races and gouges in the ratchet teeth.

rootboy 

I dunno. I just always used the method recommended in a few books I learned from back then. The dreaded flush and dribble method Bob mentions. I also learned that light oil was the proper lube with which to do it.
All of which was, apparently, wrong. But it was good enough for Eugene Sloane, so I guess it was good enough for me. And my freewheels always seemed to be fine. Back then, I had no desire, nor the skill, to do it right, by disassembling the whole unit and cleaning it properly.

JohnDThompson 

I have one. Phil Wood used to distribute them, and recommended using their grease, which I think was a mistake. The Phil grease is much too viscous, and in cold climates can interfere with the pawls catching. I've successfully used lighter greases with it, but these days prefer the Shimano MF-68nn or MF-78nn freewheels with their oil port.

steelbikeguy

If I were to guess, I'd say that it wasn't cost effective when the bodies were pretty reliable and cheap. It definitely wouldn't be cost effective for a bike shop, and for home mechanics... I don't recall many folks who were willing to open up a freewheel. Flushing the body with some oil was much faster and lower risk for the home mechanic.

Going slightly off topic, what conditions lead to failures of the pawls, races, etc.? In the days of SunTour cog boards in most shops, I used a single body for quite a while and don't recall any failures. Does it take some serious abuse to cause a failure?

As far as the issue of injecting grease... I've had trouble with a brand new SACHS Aris freewheel in cold weather. The factory grease kept the pawls from engaging, which isn't really something you want when it is 20 degrees F and you face a 5 mile walk home. I flushed it with oil when I got home, and that seemed to take care of the issue. A bit of WD-40 to get the grease thinned out, and then motor oil for lubrication.


Steve in Peoria

Ex Pres 

+1

Harvey at this years CR gathering demonstrated freewheel disassembly & servicing, and also concurred that this tool was a stupid idea. He does own, and brought, a similar tool, but it just hangs on his tool board as a joke.

crank_addict

That tool is a nice idea for the wrong application, perhaps better for auto or?

Rare occasion in having to rebuild a freewheel but the only time needed for grease is when setting the bb's. I use Tri-flow for lube. WD-40 for clean and rinse.

Cynikal 

I've used one but I wish it was smaller for BMX freewheels. After years of racing single speed CX those freewheels take a beating.

pastorbobnlnh 

In the old Regina, Atom and Maillard 5 speed models (to name just three) there is significant slop around the retaining ring and on the inside/back of the body (where it is threaded on to the hub) that can allow rather large grit to enter the internals. Maillard used plastic seals in these gaps and that helps, but sometimes they break and disappear. Shimano and Suntour freewheels have close tolerances, thus keeping out large grit.

The other big issue is fine grit, i.e. dust, which enters along with moisture and especially salty moisture which causes the bearings, races and all the surfaces to rust. Rust then provides an internal source for abrasion. If the grit is big enough or if bearings fail and crack apart, the freewheel can lock and/or gouge out the ratchet teeth. I've seen all of this occur.

For whatever reason Sachs Aris are great freewheels with lousy grease! Sachs flooded the internals with their bad grease which after many years often looks like peanut butter (but not as tasty). Sometimes the PB grease hardens to a plaster on the ratchet teeth and has to be picked away at with a small, thin bladed screwdriver.

Salamandrine 

I remember those. In the early days of mountain bikes, people thought it would be a good idea to grease your freewheel. The owner of the LBS where I worked after school insisted that all mountain bikes get their freewheels greased. Before long, it became obvious that this was a bad idea. On occasion it could cause the pawls to stick open. One occasion is enough to make it a very bad idea for a commercial shop.

That said, there aren't automatically problems. It is possible to make it work, if a freewheel that can tolerate full grease is used. Mixing some oil into light grease would be a good idea.

BTW every bike shop I've worked in serviced freewheels the same way: dump in solvent tank for a soak, blow out with a compressor, oil with Phil tenacious oil.* If a freewheel was corroded and required rebuilding, a new one would have been cheaper than paying shop rate to rebuild it.

*(Phil oil is too thick for some modern freehubs)

thumpism 

I have one and use it occasionally on freewheels. Mine does not have the zerk fitting so needs a grease tube with the right threads. Phil worked fine but I have not tried others since that dedicated Phil tube is still around.

T-Mar

The Stein freewheel injector or is old enough to be classified as a genuine vintage bicycle tool. While I agree with Bob that the only proper way to clean and lubricate a freewheel is via disassembly, many home mechanics find this intimidating and a shop's labour costs for this would be prohibitive. Consequently, the Stein found favour among some cyclists and shops.

It's interesting to note the comments about Phil Wood grease and Shimano freewheels. Phil Wood was the reccommended grease for use with the Stein and the injection port was threaded to accept a Phil Wood grease tube or Zerk fitting. Sometime after the release of the tool, the description was modified to state that they were not for use with Shimano freewheels.

Kevindale

I just did a quick search and didn't turn up any Shimano MF-68nn or MF-78nn freewheels. When were these made?

JohnDThompson 

Sorry, got my model numbers wrong. Should be 62nn (Shimano 600) or 74nn (Dura-Ace) freewheels, early to mid-80s production.

Lascauxcaveman 

Sure about that?



Yeah I think these Nose-blowers are a very cool idea, but more a of a quick lazy man's way to lube the freewheel. How are you ever going to know that the grease is both heavy enough to do the job and light enough to let the pawl springs do theirs? Too big a risk for me. And while disassembling a freewheel, cleaning and re-lubing it is a PITA, it's a fun kinda PITA, and I'm happy to do it on any freewheel I really care about.

On the ones I don't really care about, flush-dribble works fine for me.

Kevindale

Ah, thanks.

T-Mar

.

Once I had to assemble a freewheel on the side of the road. A friend's freewheels had exploded on an isolated section of road, during a rainstorm. Trying to find and pick the small bearings out of the crevices in the asphalt and then rebuild the freewheel with cold, numb fingers was not even a fun kind of PITA. It was one of the most miserable cycling experiences I've had.

Chombi1 

The question I always had with these FW injectors is, How much is too much grease in the FW?
Do we really need to fill them up with a quarter of a tube of grease?...... I think it's a bit overkill because you really need grease only at the bearings and races and not the gap between the outer and inner body castings..... The pawls and ratchet teeth can live with just light oil on them, or just some consequential amount of grease coming from the races/bearings

fietsbob

I had My Father , the retired machinist [1920-2000] Make one for the Sun Tour New Winner Pro freewheels .
those have labyrinth seals on the out side, and an Oil port on the inside covered up when it was screwed on the Hub.
Screwed on it worked pumping thru a zirk , pushed cleaning and Re lube thru the Hole ..

and then out thru the very narrow path to the outside


Others had big enough gaps around the ball races you could just add oil and spin the FW and that was Enough for a while.
you can use the grease Gun And fill it with very low viscosity grease , Or use a Needle Grease gun ..
There are or were even plastic Tube adapters to use Grease, like Phil's, Packaged in squeeze Tubes ..




...

old's'cool

+2

repechage

Maybe with really lightweight grease on a cyclocross bike.
I too just do not like filling the entire cavity with viscous grease knowing that the pawls could well not engage when you need them.

Bad Lag

My plan -


Buy tool


Buy grease cartridge.


Squeeze all grease out of cartridge into sealed container.


Refill cartridge with Phil Oil


Inject Phil oil into freewheel.


Let excess oil drain overnight.


Install freewheel.


Go for bike ride and enjoy life!