Saturday, April 25, 2009

How-To: Clean your drivetrain.

I often get asked just exactly how I get my drivetrain so clean. The answer is somewhat complicated and involved but once you get the steps down it's actually pretty easy and quick to do. It now takes me about 15 minutes from start to finish to complete the job, depending on how dirty it is in the first place. Here's what you'll need to get started.
-Bucket with water
-Chain whip
-Cassette tool
-A rag or two
I have been using gloves with this brand of degreaser because I find it burns the skin off my hands. I typically use degreaser called Mean Green, which is what the bottle in the picture is. Either way it pretty much all works well. Get stuff that is eco friendly.

Lets see what we're dealing with here. Nothing too crazy since I do this about once a week (depending on trail conditions and how much I'm riding).

Shift your rear derailleur into the smalled cog on the back so that the rear wheel is easier to remove.

Remove your skewer from the rear wheel and re-assemble it so that you don't lose any springs or parts from it.

With the skewer out of the way you can insert the cassette tool. Essentially it is a spline to hex nut interface allowing you to loosen the cassette lockring.

The next part can be a little tricky the first couple times you try and do it. You need to use a tool called a chain whip, which is the red handled tool you see. Its job is to stop the cassette from spinning when you are turning the wrench to loosen the lockring. Make sure you wrap the chain from the whip around a larger cog so that it can get a good hold and not damage your nice XTR cassette in any way. Holding the chain whip you can now loosen the cassette lockring by turning the blue handled wrench counter clockwise.

Lift the cassette off and you will reveal your freehub body. Make sure to keep good track of any spacers or parts that you are pulling off the freehub. Many wheels like Mavic and Shimano will have spacers that shim the cassette away from the wheel. Many cassettes will have spacers that separate the cogs from each other. In my case I have none of these. The Cobalts have no shims and the XTR 970 (new generation) cassette has no cog spacers. Put all parts including the cassette lockring together on a rag.

Feel free to take a little time to clean it this area on your wheel up. After all that's why we're here in the first place. You can now access hard to reach areas like the hub and lower spokes.

Now lets tackle that dirty cassette. Spray it down with degreaser and use the toothbrush to get all the crap off.
The purpose of the degreaser is to make grease water soluble. You still need to clean off the dirty and potentially corrosive degreaser. Use your bucket of water to rinse each cog clean.

Once you have finished cleaning each cog just set them aside on a rag all together so you don't lose anything and let them dry.
Moving on to the next step, cleaning the chain. For this you'll need the same bucket of water, some more degreaser, and a chain cleaning tool like this Park Tools one. It is best to clean the chain with the back wheel off the bike. That way you don't have dirty degreaser finding its way into the freehub and bearings in your hub.

Fill the chain cleaner to the fill line with degreaser. For this tool the fill line is roughly 1/2 way.

Snap it together over the chain. I am putting it over the chain stay because I will be rotating the crank clockwise. This way it pulls the chain through the cleaner with no problem. Give it a good amount of rotations (15ish) to let the degreaser really do its job.

Take the chain cleaner off the chain and pour out any remaining degreaser (remember it's biodegradable :-D ). Rinse the cleaner out in your bucket of water to get out any dirty degreaser. Fill it back up to the fill line with clean degreaser and do it all over again. I always run 2 cycles of degreaser, takes an extra 30 seconds but leaves you with a much deeper clean.

After rinsing the chain cleaner out from the 2nd cycle of degreaser go ahead and fill it up to the brim with water (don't worry about the water being crystal clean, it's still good enough).

Run the chain through the chain cleaner full of water just like you did when it had degreaser in it. Remember the degreaser is still on the chain and is dirty and potentially corrosive so you gotta get it off of there. When you have completed 15-20 rotations of the cranks remove the chain cleaner, rinse it out and then fill it back up and do another cycle of water. Again doing this twice only takes an extra 30 seconds and gives you a much cleaner chain.

Dry your chain off with a clean rag.

Now that your chain is sparkling clean lets get back to assembling the cassette since it should now be dry. Your cogs will only go onto the freehub one way so don't worry about doing it wrong. The only thing you need to worry about is making sure they go on it order (largest to smallest) and that you reassemble any washers or spacers that were in there. Since you kept good track of all that stuff and this is not rocket science, you are prepared for this step.

A tip to remember is that the printing on the cogs faces up. Also look for the one big fat spline as a good reference.

Now gently start the threads for the cassette lockring. Be very careful threading this onto the freehub because the threads are delicate and some freehubs are soft alloy. I cannot stress enough that you do not want to cross thread this at all, take your time. Tighten it down, you won't need the chain whip. The freehub locks when you try to spin the cassette clockwise which is the direction you are turning the wrench to tighten. You don't need to reef on it with He-Man strength, on a tightening scale of 1 to 10 I give it a 7.

Now that your cassette and chain are clean you can finish the job by cleaning your pulley wheels and chainrings. I do this just by wiping with a clean rag. You can use some bike lust on the rag to help you get the gunk off. The reason I don't use degreaser on the chainrings is because they are too close to the bottom bracket. You don't want to seep dirty corrosive degreaser into your nice Chris King BB. If your cranks are so dirty that you want to clean em up really well then pull them off the bike. Doesn't take long, I'll show you how to do that later ;-)

Now put the rear wheel back on the bike by holding it firmly against the dropouts while simultaneously tightening the quick release to make sure that it is square in the frame.

Here are a couple before and after shots.




All done and clean. Now lube your chain as soon as you are done to leave time for it to soak in.

Questions, comments, suggestions, all welcome.