What to use to clean a really dirty drivetrain?
 

My plan is to remove the derailleurs and soak them, then use compressed air to blow out all the gunk. I'll give the bike a good cleaning and replace the chain.

Is soaking in a degreaser a good idea? Any potential damage to parts or finish with an overnight soak?

My choices at home are citrus degreaser, TSP, isopropyl alcohol or methyl hydrate. I also have xylene but hesitate to pull that nasty stuff out. What should I use?

I would not soak metal parts in a solvent overnight. Some solvents can encourage hydrogen embrittlement if left in contact long enough. Now spraying a layer of WD40 on the parts to be cleaned to start the softening up is fine. Kerosene is a well proven solvent that won't hurt metals. After use if the Kerosene is left still the grit will settle out and good/clean kerosine can be poured off for use again. Andy

I agree with Andy. Kerosene, or it's less smelly and cleaner evaporating cousin OMS (odorless mineral spirits), are the most effective degreasers and can be reused by letting the dirt settle and decanting the clear solvent. Kerosene is available by the gallon at many gas stations and OMS in any paint store or big box home store.

DO NOT use gasoline.

I generally use citrus stuff but rarely if ever do any long term soakings. I would probably just go with Mineral Spirits and use that if I really had to soak it for a longer bit however unneeded. Just use an old tooth brush and some citrus degreaser and you should be set. Or even some hot water and Dr. Bronners can help loosen stuff.

Avoid Xylene, imo.

Too late for this episode, but if you wax your chains boiling water makes everything spotless.

No gasoline, no overnight soak - noted. I used to use Xylene in my composites business and I know it's effective but even short term exposure to the fumes is not healthy.

I ended up using the citrus degreaser. Put the derailleur in a closed container and shook the bejesus out of it - poor man's ultrasonic cleaner. A bit more scrubbing with a toothbrush and she came out all sparkly.

Thanks for the input.

I'm a fan of Simple Green. I rarely need to soak anything long term with it and an old toothbrush scrubs aways the gunk and grime after a short dip in it. But I do suggest you investigate if your derailleurs have any plastic parts like bushings that may be weakened by some harsher solvents.

This one is an old, 9 speed Ultegra. All metal, AFAIK.

I would advise against soaking entirely. There is lube in the joints and pins and a solvent would remove it. Disassemble the unit to the extent possible, wipe everything clean, and reassemble with lube on all contact parts.

After 20 years, I doubt there is much original lube left in pivots. Also, some lightweight lubricant like Tri-flow should restore it. It's better to get all the grit and grease out of the joints IMO
.

I like this stuff, it's not gasoline.
https://www.amazon.com/Totally-Aweso.../dp/B007TX3W9C

I don't buy it from amazon though.
I buy it from dollartree
https://www.dollartree.com/las-total...ll-64oz/963845

As a high volume bike flipper, I have to clean bikes and components fast and get it to look showroom new.

I won't go into detail my routine or what I use, too many Karens and haters here. I decide what is best for me and my income.

I will say I've never had to remove derailleurs to clean them.

A used toothbursh and any liquid will do 95% of the work. If you feel a Park Tool brush is necessary, go ahead.

I understand the FD usually can't be disassembled, but tampering it means realigning it all over again and more paint bites.

The RD is more forgiving as you can remove the jockeys without taking off the RD.

The more you do this, the more you learn what works best. After overhauling a few hundred bikes you get the gist of it.

This is the poor man's ultrasonic cleaner.

https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

Siphon sprayer
 

I actually remove my pulley wheels and put the whole derailleur into a sonic cleaner (with degreaser) for 15 minutes. Quick rinse with water makes it almost look new. I hand wipe the pulley wheels and put it back together with some spot greasing and that is about it.

For the people who dip the whole rear derailleur in a bath of cleaner: How do you reapply/refresh the grease in the main pivot spring.

So far as I've been able to figure it requires pulling the massive e-clip of the hanger bolt, unloading the heavy coil spring and manually cleaning out the grease destroyed by the chemical bath. Then reversing the process.

Loading up the heavy coil inside the knuckle is a challenge if done in such a way that allows for reinstalling the e-clip.

Please advise.

I like this guy's video - I go by his steps and products .

Make certain that you get the real stuff NOT the milky-white substitute.

For most all ders the B pivot, and it's spring if any, really wants grease. Flushing out the old is only half the job. When I was a full time wrench in the Rust Belt I would have to disassemble, derust, regrease and reassemble these top pivots due to corrosion making them freeze up. I got fairly comfy doing this but still struggled sometimes. Placing a 5mm hex wrench in a bench vise pointing up to hold the B pivot bolt, having a thin flat blade screwdriver to rotate the backing plate and having needlenose pliers to hold the clip while you press it in place while also pushing the plate down on the bolt is my usual plan. Usually a one person job although a skilled third hand can be nice.

I suggest only adding a thin lube (Triflow is my go to) to the various pivots, and pins (don't forget the cable adjusting barrel threads) after a spray and wipe off cleaning. Pulleys are easy to take apart, clean, grease and reassemble. Andy

If its really crusty then just use a paint brush and tooth brush with old used motor oil or used ATF. Get the crust off first then go to other steps. Solvents and chemicals are rarely needed...

If ya do need a solvent then Charcoal Lighter Fluid is probably the easiest to get.

Wrench in a vise with a flat blade to rotate.
I don't know why I never thought of that. Thanks! :thumb:

https://cimg1.ibsrv.net/gimg/bikefor...df86bccd8d.jpg
sorry, couldn't resist. found this under "flame thrower bike cult" whatever that is ...

Dawn dish liquid. Brush. Flush with garden hose. Spotless.

Big fan of the LA awesome products and dawn soap. Dollar store is great for saving some money. For chains, i use a mason jar, first with the la awesome, shake it up and let sit for about 20 minutes, then rinse and switch to the dawn soap for two extra rounds of cleaning. Use high airflow to dry the parts. Re lube with triflow for pivot points. For chains I use the rock n roll, was using the red absolute dry, but am really starting to like the rock n roll holy cow lubricant.

Cheers!