Degreaser and Hub?
 

So I just clean my chain and cassette by spraying citrus degreaser on my chain, derailleur, and cassette. I just wonder if there's any chance or degreaser getting into my rear hub and cause the grease inside to go away? It this a common problem and a serious one? Or is there another way I should use to clean them next time without using fancy stuff like a chain box or taking out the casette? Thanks

Unless you sprayed it under a fair bit of pressure or washed it off with the hose aimed directly at the hub, you are probably ok. most hubs are fairly well protected from water and dirt. Use the degrease spray gently and wash it off with a mikld water stream.

I hear ya and worry the same. It seems like degreaser can work it's way into the freehub body and start to dissolve the existing grease.

Hillrider is probably correct. But to be safe, I do remove the chain and cassette to scrub, soak and clean them. It takes more time, but I believe the cleaning is superior to the on-bike method.

I've seen multiple cases of people spraying WD-40 on freewheels and it ruining the grease inside. Freewheels and older hubs have *no* seal between the bearings and the outside, and if something runs into the bearings there is nothing to stop it.

I'd echo what Hillrider said and stress that you want to apply and rinse from the "edge" of the cassete rather than spraying either the degreaser or water onto the "face" of the cassete. The idea being to avoid spraying anything towards the opening between the cassete retention nut and the axle. That opening leads into the inner workings of the freehub and wheel bearing so it should be avoided as much as possible.

I'd further suggest that if you must use a citrus degreaser that you buy it in the gallon bottles rather than a spray can. It's far, far cheaper to do it that way. Then pour out a little into a dish and use a brush to apply and scrub. That'll give you a lot more control of where the degreaser actually goes plus allow you to use less of it by being able to scrub with the brush.

One of the chain cleaning gizmos also allows you to clean the chain on the bike quickly and efficiently. And, for the most part, it further avoids having too much degreaser around the cassete.

Your basic reasoning and concern is well founded. Washing can serve to wash out lube from and dirt and grit into bearing and pivots . You need to exercise care and common sense trying minimize doing those things. IMO, more damage is done washing bikes than leaving them dirty.

+1 Sort of killing them with kindness. Over enthusiastic cleaning has probably damage more components then helped them.

There's certainly things you want to avoid when cleaning. Such as using a hard blast from a hose. Such high velocity water is actually able to lever up seals and pass through into the internal "sealed" area. This comes up on motorcycle forums often where some folks want to use a pressure washer to clean their bikes. It results in a bevy of "NO! ! ! !" from the rank and file for this reason. Even a hard jet straight from a regular garden hose is able to lift away a seal if it hits just right. Bottom line? Hoses are great but limit the power of the spray to something you'd be willing to use on a delicate garden plant.

While I tend to agree with the "killing with kindness" comment on the other hand when anything on a bike sounds like sand rubbing between two plates of glass then it's time to clean.

No question, the problem of over cleaning doesn't justify negligence. There is certainly a middle ground between doing way too much and doing nothing.

The thing is, bikes often don't even have seals, especially if you're dealing with components that aren't fairly new. Runoff from other parts can easily find it's way into your bearings, no pressure required. No seals on my loose bearing headset, no seals on my loose bearing road hubs. Dustcap, but no real seal on my freehub. I've got a sealed bottom bracket, but that's about it.

If you want to leave the parts on the bike, then I suggest getting a pourable citrus degreaser (Finish Line seems stronger than Pedros, that's what I use), and using a cheap 2" paintbrush. Pour a small amount of degreaser into a can, dip the brush, spin your rear wheel backwards and swab the cassette cogs as they turn (and you can get the chain while you're at it). Keep an eye on where the degreaser's running off to and try not to let it near the bearing areas.

After a minute or two, rinse away the citrus degreaser with hot sudsy water, dry the chain as much as possible, and relubricate it promptly. Rinsing the citrus degreaser away with Simple Green Foaming Degreaser first will get stuff even cleaner, the two degreasers annihilate eachother and the grime comes pouring off in the process. But if you're working on a daily-driver bike that's just going to get dirty again, don't get too carried away trying to make it spotless.

And that leads right into the thread I was going to start. How often do you service your old, sealed hubs? Mine is Shimano 600 hyperglide, recently acquired. I've never disassembled a freehub before.

I assume you mean cup-and-cone hubs with dust seals and some O-rings, not true sealed cartridge bearing hubs. I service my Shimano and Campy cup-and-cone hubs about every 6000 - 8000 miles which used to be once a year but is now evey two years since I split most of my riding between two bikes and neither is subject to a lot of rain or salty roads. For my rain bike I service them about twice as frequently.

Without the seals, high-pressure water will displace the grease from the bearings. I've seen grease blown out of e.g. headsets simply from driving long distances with the bike on a roof rack.

With a bit of care you can still avoid a lot of the muck getting to the entry around the shields that are fitted to the wheels or other parts in such cases. I road for years through winters and cleaned the bike regularly as a result whenever it sounded like sand between two plates of glass... which in the worst times of winter was about once a week. The front wheel on this particular single speed budget build only had shields instead of seals. By watching what I was doing I would go two years between taking it apart. And even then I did the hub more due to feeling guilty than anything else. Sometimes it's a case of tilting the wheel or bike a certain way so the spray can't flow in. It just needs a bit of considered attention to avoid mucking the stuff up.

Trust me, you do NOT want to pull apart a freehub unless it's to sacrifice it to the Gods of Curiousity. They are a bugger to put back together and just more trouble than they are worth. However you can effectively clean and lube the Shimano ones very easily. After you demount the cassete use a 10mm allen wrench held in a vise to undo the hollow freehub mounting bolt. Clamp the key in the vise and then pull on the rim for leverage to snap it loose. It'll come off with a crack like you get with freewheels often as not. WIth the tube bolt out the freehub will lift off easily. Set aside the seal found under the part which sits against the hub flange if there is one. I also like to ease out the dust shield on the outer side so I can clean and grease the bearing later on more easily.

To flush the freehub clean you dunk it into solvent. For this I do NOT recomend you go with a citrus degreaser since it means water to flush it and you don't know if you got it all out or not. Solvent for this is far better. Dunk, spin it while in the solvent and then lift out to allow it to drain. Repeat a couple of more times. If the freehub was really dirty switch the solvent and repeat the dunking, spin and drain a few more times so it's nice and clean. Now make up a soup of half solvent and half a fairly thick bodied oil. I use some honey like chainsaw bar oil I got years ago from Home Depot. Being thicker it'll stay longer even in a thin film of the stuff. Dunk and spin in the soup to fill the inside of the freehub. LIft, drain and sit on a paper towel in a tray for about an hour to finish draining. Reinstall it and go ride. The solvent inside will take a day or two to fully evaporate if you use a fairly slow dry one such as mineral spirits AKA "low odor paint thinner". As it drys and if you used the thicker oil like I do the pawls will quiet down and sound really silky thanks to the fairly thick body oil.

DO NOT try to mix grease and solvent. I tried that and found that even the light film of grease on the pawls prevented them from following each tooth. So my freewheel lockup was spotty at best until I flushed it out with the new solvent and bar oil mix.

Freehubs I've done with this worked easily for 4 years worth of Pacific North"Wet" conditions before showing signs of wanting another bath.

Every 650 miles or so I remove the chain and clean it. I use the time it is in the ultrasonic cleaner to clean the cassette and rings with a cloth wrapped around a thin metal ruler. Turning the wheel backwards keeps the freehub from freewheeling. To do much more is a waste of time.

The seals on radial bearings are no more than dust seals and are not designed to keep water out.