Is this a good idea?
 

I think my issue is the free-wheel being gunked up. This is what my bike-friend told me; he lubed it for me a while ago but told me it was just a band-aid fix and that I really needed to take it apart and re-grease. After a few weeks, my pedals once again move when I push the bike backwards.

I want to learn more about my bike, so I want to do it myself. I'll be going to a local bike DIY place, where there will be staff to help.

Is is correct to assume this job should take no longer than a few hours? And that the chances of me breaking something or needing a new part are minimal? I have an older bike, and the place doesn't really sell parts beyond the very basic. Also if I can't get my bike apart & back together in less than 3 hours I'll be screwed.

New freewheels can be had for around $10. Opening one up to clean and lube would be next to impossible (actually, only reassembly would be next to impossible). Just purchase a new freewheel (get one with the same number of cogs and with the same number of teeth on the cogs) and take the bike and freewheel to the bike DIY place, Should not take more than half an hour to swap out.

And if you really want to take it to the next level, take the old freewheel apart and see what you would have been in for trying to clean and lube.

freewheels can be disassembled, but it's rarely done. They're reasonably inexpensive, so most will simply replace them. Otherwise you should be able to find plenty of threads here on how to flush and relube freewheels w/o disassembling them.

+1 on getting a new freewheel or flushing and lubing, if you really want to. I took apart a freewheel once. There are literally 70-80 tiny ball bearings in there, on two levels if I remember correctly. It is very difficult to get everything cleaned up and back in there, in order. In the past, I've flushed the entire freewheel with WD-40 by spraying in the crack (at the top) between the part that rotates vs stay still if you were to rotate it in your hand (you can also do this in the back). Then, wait a day or two for the solvent to evaporate out...then lube, using a similar process. Set somewhere on newspaper/towel/plastic, and let the excess drain out. Wipe the whole thing up...put back on to bike. I did this once...now, I'd just find a new/used freewheel in better shape. It really isn't worth the effort. Any place that sells used bike parts will have many old freewheels that are functional If you spend a lot of time with solvents, don't forget some gloves. The following link is a bit better explanation on freewheels and lubing them...

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

If you have a grease-injector tool for free wheels (I have a Phil Wood FW grease injector) and to lube a freewheel with fresh grease takes a couple minutes. You just need to remove the FW, attach the tool with a tube of grease, squeeze a bit for maybe 15 seconds until old oil and black sludge ooze out the front, then remove, wipe off excess, spin the freewheel to loosen up the grease and wipe off more excess and re-install.

For a more complete overhaul, if there isn't any play to adjust, I don't bother taking apart the FW, and simply soak the whole unit in a solvent tank and spin the center a little to let the solvent work in. Commercial tanks w/ ultra-sonics vibrate and do an awesome job on these parts and you can come back after just 2 minutes and see a ring of grit under the FW if the tank has relatively clear solvent. You can also just let soak in a standard big plastic tub, like for butter, and some degreaser and put your FW in there, and get some nitrile or rubber gloves and spin the center of the FW while soaking in the solvent. Leaving it in the solvent for 15 minutes or so, then taking a hose and rinsing it under pressure, and then soaking in clear water and spinning gears for a minute will help clean the FW.

In a shop, they have compressed air and can use that to blow into the crevices to flush out remaining solvent. You can do that at home too if you have the equipment. Otherwise, I just simply let the part sit in the sun for an hour on a hot day and it will literally get REALLY hot and cook off a lot of water or solvent from inside. Then I repeat with the freewheel injector. The FW will ooze for a week or two and so wiping down the rear drive-train is a good practice. Then the FW seems to just work great for almost a year before I feel the urge to do that again.

thanks everyone! I'm going to try flushing it (hopefully the DIY bike depo has a FW grease injector), and if it stays cranky after that I'll get a new one.

thank you for stopping me from trying to take it apart, that does not sound like something I want to do.

Don't all drivetrains do this? I assume you mean that when you spin the wheel forwards, the pedals rotate, right?

Taking apart a freewheel is more trouble than it is worth not to mention that there are 23 1/8" bearings in the back and 9 or 11 more 3/16 bearings in the front - any they all fall out at the same time. Don't ask how I know.

The best thing to do if you have a sluggish, gungy freewheel is to soak it overnight in Odorless mineral spirits (solvent) or if you have access to a parts washer run the solvent over so it washes through the bearings, pawls, etc. Slosh it around real good. Then let the thing dry thoroughly. I let my complex parts just sit in the sun on the driveway for a couple of hours. After this when you spin it, it should sound clean but dry. Now put in the lubricant. My absolute all-time favorite for lubricating freewheels and free hubs is Chain-L No.5 (a play on Chanel No.5, the perfume). This stuff ain't cheap but it is perfect for lubricating the bearings and pawls without clogging them up. It is about as viscous as honey and you put your freewheel small-cog down (on newspapers or corrugated, you don't want this stuff to soak into your concrete floor) and lay on a ring of oil on the small gap between the cogs and the core. Let it soak through (a few minutes) and do this again twice more. Leave it for 12 hours. There will be a pool of oil where it rests on the paper and just the right amount inside. Spin it and the pawls will be nearly silent. This stuff won't gum up the pawls like grease but give better lubrication than "regular" oil or even wet chain lube. DON'T use dry chain lube (wax based), WD-40 (it is NOT a lubricant, it is a preservative), or Boeshield T-7 (too thin). Remember to heavily grease the threads of the freewheel AND the hub before screwing it on. Any extra will just squeeze out. You can destroy a hub trying to remove a frozen freewheel. You don't have to tighten it more than hand tight. Riding it will tighten it more and using a wrench to screw it on will just make it harder to remove in the future.

200k

You haven't stated the problem correctly. All bikes, even with a perfectly working freewheel, rotate the pedals when they are pushed backwards. If the bike rotates the pedals when pushed forward, then you do have a lubrication or wear problem.

Soak it in a solvent like diesel fuel or mineral spirits, then when it's free, spray it full of white lithium aerosol grease. This stuff will require several applications as it goes on thin, then dries but loses volume. The grease injector would overcome this difficulty but your shop may not have one.

It is definitely very important to get grease in there because it's what stops the fw from getting full of grit as well as providing lubrication.

Grease is specifically what you DON'T WANT in a freewheel. A freewheel only needs light lubrication because there are never moving parts under load. There' motion when you coast, but no load, and when you put a load on it while pedaling the ratchet engages and the freewheel moves as a unit.

After soaking and flushing with solvent, shake it out as well as possible. If you fon't have any time, tie a rope to it through the hole and go outside and spin it dry. Then apply a heavy sticky oil like Phil Tenacious or my stuff, and let it work in. I do this with the freewheel on a paper towel and know it'sm oiled when the oil starts to drain through the back.

The entire job or washing, rinsing, drying and oiling a freewheel takes about an hour or less so you should be in good shape.

I'm glad someone else caught that... I was starting to worry.