Best way to Clean and Degrease a Dirty Drivetrain?
 

I've noticed there is a fair bit of resistance coming from the pulleys in the rear derailer while spinning the cranks backwards.

I'm well aware that using a pressure wash on a bike is a rather terrible idea. What if I pressure wash the frame, chain and derailer at a safe distance first before removing the chain and derailer for a proper degrease?

Or should I just remove the chain and derailer in the first place to get to work? What would be the best way? Using some sort of shallow bin filled with degrease and a brush?

There are a lot of crevices and what not such as in the front derailer as well which have been caked in dirt and grease for a very long time. Any suggestions would be much appreciated.

For most people doing this at home the easiest would be something like this:

Get some good degreaser. I really like the Pedro's stuff, it's thick, stays on, and cleans well.
Put some in a cut down water bottle and use a 1" brush to paint it on the cogs, chain, and rings. You can definitely slop it on the derailleurs too.
I have a toilet cleaning brush that works well on the cogs and chainrings, I use a cheap car wash sponge w/ soapy water (I use Dawn) for doing the chain. Wrap the sponge around the chain and back pedal. Rinse w/ your hose or whatever. Dry. Lube. Don't let it get dirty again. The more you clean the less time it takes.

And of course...this post should be in 'bicycle mechanics' not GD.

Since you asked for the best way:
Take everything off and use a proper parts washer and brushes. You might be able to find some cheaper ultrasonic cleaners and if you have enough space in one you can clean it all. Granted that cheaper cleaner may not work as well but hopefully will get you a couple decent enough cleans.

Also when doing a drivetrain clean, it would be a good idea to just go ahead and remove bottom bracket and check other parts and replace cables and housing at least for derailleurs.

Ultrasonic cleaner

Forget all that. Get a hand-held propane blowtorch and just burn off the accumulated grease.

Automatic transmission fluid won’t “degrease, clean, and lube the chain all at the same time”. Using it the way you are suggesting is only going to result in having oil all over the bike in places where you’d rather not have oil...like the rims and brakes. ATF is largely high molecular weight mineral oil and, as such, will stick to everything. There are far better solvents out there and far less messy lubricants. Dish soap like Dawn would be a better choice...and it’s a really poor choice.

Using a pressure washer on a 1980s bike might have been a bad idea but the seals on modern bikes have vastly improved. Even back in the 80s, it wasn’t that big of a deal. I’ve been using pressure washers since the 80s (on the rare occasions that I actually get around to washing a bike) without ever getting water into any bearing on the bike. I didn’t use the wand at high power around the bearings but now I wouldn’t worry about it. I don’t consider Shimano hubs to have the best seals but I wouldn’t hesitate to use a pressure washer on them.

But your problem likely isn’t going to be fixed by washing with a pressure washer...or soap and water of any kind. If your derailer jockey wheels are binding because of crud, you need to take them off and clean them. I’d use mineral spirits because you’ll only need a little bit. You might have to scrub them a little (wear gloves) as well. Put the derailer back together and then use a power washer.

Finally, at the risk of being flamed, find another lubrication regime, preferably one that doesn’t leave your drivetrain as a dirt magnet.

I often scrape gunk of the jockey wheels with a flat screwdriver, then scrub them with an old toothbrush and Simple Green---but any degreaser works. Mineral spirits work well.

Thank you for the suggestions. It looks like the crud stuck inside the derailer should be easy to blast out if I hit it from a couple different angles though.. Please bear with me and tell me what you think.. So far i've rehauled the hub on my rear rim and replaced the badly bent axle. The bottom bracket feels very smooth (may have been reserviced in the past by previous owner) but I will be taking apart the BB to replace the spindle with a shorter one, as my new crankset sits too far out on the spindle. The front derailer does not reach into second gear. Plus the cranks are wobbling slightly, so I am not too worried about getting water into there anyways.

I live in a condominium, so my only real choice in the mean time is to head over to a car wash bay. I don't know how friendly my friend or the local bike hub will be when they find out I am planning to use their local resources for a degreasing. The pulleys are not binding or anything, but in general there is so much dust and greasy crap all over the bike/frame I reckon it would be easier to start with a pressure wash first and simply not to use high pressure around the bearing areas. Then I can head over to the bikehub the next day and do a proper degrease there if I still need to. Does that make more sense? Or should I still do the degrease first and then pressure wash?

I've learned the hard way not to use excessive lubricant on a bike's chain, especially when the chain is dirty to begin with.. lol

If the cranks are wobbling and the front derailleur can't reach the big ring .... First find out what is up with the cranks. Likely they are already ruined or will be soon, unless the BB bearings are completely shot.

Second either the FD is completely misadjusted, or possibly the chain ring is wobbling too far for the FD to reach.

Either way, it would be a Very bad Idea to ride the bike anywhere until you fix whatever is wrong with the cranks/ BB.

As a last resort, 1,1,1 Trichloroethane will degrease even the most stubborn mess.

It'll also give you various nasty cancers.

I replaced the crankset with a new one. It sits further out onto the spindle than the original crankset.

the BB feels smooth when spinning it with the chain removed, and the wobble is slight.

I'm still going to take apart the bottom bracket and replace the spindle.

Dude, please. Don't make this complicated. Spread out a drop cloth or some cardboard. Flip the bike upside down & take the wheels off. Wrap the brake pads with plastic sandwich bags. Put on some really old clothes. Get a can of WD-40, a toothbrush and, some rags. Use a fan for ventilation. Start working on that thing. (Try not to make a huge mess). If you get oil on the rims wipe it off with a rag soaked in alcohol. It's all good. That's it. That's all. Have fun.

The best way to clean a derailleur, pulley wheels, and cogs, I have found, is throwing them out and buy an IGH.





No, seriously, though: You can get some citric acid power, dissolve a little bit in boiling water, add cold to cool it down so it's safe to handle. Use a brush. Best degreaser ever (for non-brakes). Rinse with cold water. It dissolves fats and oils very efficiently. It is also better than vinegar for descaling your kettle. Fill the kettle with cold water, put in the citric acid powder and boil it. Rinse after.

If there is any play or wobble at all in the BB something is terribly wrong. No part of the bike bears as much force as the BB---all of your weight, all of your power, every road shock is transmitted through the BB.

If I lived in a condo, with no easy way to do an outdoor chain cleaning, I would do this (which is what I do to clean the chain on my old bike that stays in the basement on the trainer for riding on Zwift):

Buy one of the chain cleaning tools, like this one. Go to a big box store, or online, and buy a cheap gallon jug of Simple Green. While you are out there buy a new toothbrush. Find a rag, place under bike chain.

Put the new toothbrush near your toothpaste, take the old toothbrush and dip in Simple Green and clean jockey wheels, cassette and chain rings.

Fill the chain cleaner with Simple Green, clean the chain. Dump the dirty Simple Green, fill chain cleaner with water - clean the chain again, to remove the degreaser. Dry chain off with the rag.

Oil chain. Done, no mess indoors.

Agree with the other comments about the other issues with the drive train.

My friend told me that a slight wobble isn't anything to worry about... I guess I'd have to agree with you because I can sometimes feel a bit of a clunking when I pedal. Thank you for pointing this out. Surprisingly enough, the bearings feel fairly smooth in there. Any reason why you think this happened? Just old age?

Luckily, I'll be visiting my local bike hub and replacing the spindle tommorow anyways. Thank you for pointing this out. Any suggestions on how to get it out if it proves to be stubborn?

As for Degreasing, I think my best bet would be to remove the parts and let them sit in a tub of degreaser before scrubbing. I actually scrubbed the middle part of the pulleys yesterday using a toothbrush/rag and lysol spray quickly and it did help free up some resistance. I'll look into doing a more thorough job tommorow at the hub.

As an added bonus, Lysol kills germs too. In case anyone has sneezed on your bike recently.

The easy option is to put the bike on a stand, spray liberally with a degreaser - I often use Simple Green - then hose the bike down to rinse it all off. I have used the "jet" function on my hose sprayer without issue - it's a big step down from a pressure washer.

If you really want to get things clean, remove the chain, chainrings, cassette and run them through an ultrasonic cleaner. Also, remove the rear derailleur pulleys to clean them out. Rags, soft brushes, q-tips and pipe cleaners are your friend.

I am no genius and not even a decent mechanic ... but I have been rising for more than five decades and doing pretty much all ny own bike-building and maintenance except wheel-building for about 35 years .... I don't want to disagree with your friend who says crank wobble is okay .... but NOT ON MY BIKES.

If you have ANY play in the BB you are in trouble. The spindle is harder than the cranks and will stretch the holes. The bearing can fail, and the spindle will eat the outer cups. (been to all those places, done all those things.) The whole unit can wobble and eat the threads in the BB shell, which can be a real bear to repair .... basically you need to buy a rescue BB.

You should be able to move your cranks in one way only---spinning. Any movement in any other direction indicates a big issue which will only become bigger.

One thing about a seized BB---you'd better have a chain-break tool because otherwise you can't roll the bike home. I have actually rigged a sling out of a spare inner tube and a bandana to lift the rear wheel because carrying the bike a few miles home wasn't happening, I have two loaded panniers I would have needed to carry also, and I needed the bike. Five miles with 50 pounds of bike around your neck leaves lasting impressions.

There are a few ways to get out stuck BB cups ... many will also take the threads. I think there was something I found on Sheldon Brown's page involving a 1/2 in threaded shaft, multiple nuts, a crescent wrench, a ratchet, and a breaker bar. i will check.

https://www.sheldonbrown.com/bbcups.html
https://arcady.genkin.ca/2016/03/an-...-removal-tool/

The idea is that as you turn the ratchet, it tightens the bolts and washers onto the right-hand (fixed) cup and increases your grip the harder our turn. Sometimes the cups get galvanically welded in place and the little flats on the cup don't offer enough purchase.

Lots of penetrating oil, lots of patience.

Perhaps you are thinking of trichloroethylene?