Servicing cup and cone bearings - degreasing?

[Gattonero]

IME if you don't clean parts thoroughly you have missed half the benefit of bothering to take them apart at all, which is to be able to inspect them properly. To do this they need to be properly clean, and there is absolutely no reason to spend longer than necessary 'cleaning' parts, especially in a way that still leaves them dirty and difficult to inspect.

cheers

This is what you get when cleaning a part by using an old tshirt (visible in the background) with GT85 or similar. I'd say is clean enough for inspection




There's no need to go mad about what you're using, as long as it's something that's absorbent enough and won't leave noticeable lint or fibers. As said above, I use only once a clean rag for delicate parts like hubs. Special parts like disk brake calipers or master-cylinders require more attention due to their tight tolerances where the smallest piece of contamination is best avoided.

[Brucey]

if you have inexhaustible supplies of clean rag and you use some GT85 (or similar) you can certainly get stuff reasonably clean. But as I mentioned before if you use rags only then you quickly end up with lots of rags contaminated with grease; what are you going to do with those?

When parts start to wear or fail there are of course marks on the wearing surfaces. But of course there is also wear debris. If you can inspect the wear debris you can learn a lot. As previously described if you use a disposable wipe you get a better chance to examine the wear debris, and this can tell you if the bearing surface is wearing quickly or slowly, if there has been contamination or corrosion involved, all kinds of things that might otherwise be difficult to determine.

BTW using something like GT85 or WD40 is indeed harmful if it remains mixed in quantity with grease, but the solvent evaporates, leaving a film of oil that is not particularly detrimental to the grease, not in the quantities that are anticipated, anyway. In a lot of workshops compressed air is used to blow parts down and remove any solvent and remaining debris. If you don't have compressed air but you do have a track pump and it came with a pointy nozzle (for inflating airbeds etc) you can use that to blow parts down if you want to.

A final point about using GT85 (or WD40 or similar) is that the parts that are wiped with it have at least some corrosion protection. If solvent alone is used to clean steel parts, and they are left in an unheated shed, they can start to corrode in just a few days.

Hydraulic brake parts are best cleaned using solvent and clean (filtered) compressed air. Even one tiny fibre across a seal edge can lead to a persistent hydraulic leak.

I don't particularly like using aerosols, but unlike other containers of fluid there is almost nil risk of it being contaminated, and it doesn't evaporate or get spilt easily. You don't need much; if you use GT85 only to help wiping down your bike components, a single can could last several years.

cheers

[Gattonero]

The vast majority of times, thanks to the weather in this country, failures are due to contamination that promotes rust or corrosion. Pitting and accelerated wear will cause bearings to wobble, and this create the conditions for proper failures as in freehubs and the likes.
Failures of this kind can be inspected mainly for learning purposes, as most often there's no other solution than replacing the whole part, i.e. I won't trust anymore a freehub that has already broken pawls.

While the general wear&tear is pretty easy to spot with marks of pitting or the rust, conditions of the latter, don't need much cleaning and a neat rag in the size of an A5 paper sheet would easily clean an entire hub; past that the same rag gets used for g.p. cleaning of grubby parts where there's no need for inspection nor the risk of contamination, i.e. removing the crud from jockey wheels.
The average home mechanic can service his entire fleet with just one tshirt, as you can get 8 small rags out of it (4 from the front, 4 from the back, 2 small from the sleeves).
Assuming a hub service twice a year, one tshirt can clean two wheelsets and the leftovers still be useful. If you have removed the most part of the grease on the same side, then you fold the rag against this greasy side and left with a nearly clean side that is small but perfectly usable for removing grime and crud.

Obviously, if one is working for the purpose of warranty inspection, would be better to use a white fine cloth or disposable paper of decent quality.
For suspension forks I use something like this, two pounds for about 400 sheets is not a bad value
https://groceries.morrisons.com/webshop ... EARCHpaper

[Brucey]

IIRC I'm presently using loo roll which was (I think) £1 for 1200 sheets. Nothing like as good as proper wipes or even decent kitchen roll of course, ('insubstantial' is the word that springs to mind) but the small sheets can simply be stuffed into nooks and crannies to clean them.

The other thing I have found surprisingly useful is to cut the bottom from a drinks can; this shallow recess is good for cleaning/inspection of ball-bearings, and is itself very easily wiped clean.

cheers

[Bonefishblues]

Surely people must be using straws and cotton buds given the stats on their usage?

I love the granularity of this Forum sometimes (no, I really do)

[Brucey]

BTW I agree that water ingress and corrosion are major causes of bearing failure on bikes. My take on this is that if the parts were lubricated correctly in the first instance (i.e. with more, better lubricant) and/or the parts were designed with lube ports, much of this damage could be avoided.

One of my lecturers put a net annual global cost on 'wear' and it was a truly astonishing number; he reckoned that much of the damage would be quite avoidable, and I agree; failing bike parts are entirely symptomatic the larger problem, more or less.

In a workshop environment if a part is damaged or even suspect in any way, the reason is largely academic (most of the failed parts won't have been into that workshop before) and the outcome is clear; it should be replaced. Few customers are prepared to pay workshop rates and accept any perceived risk of the part failing. [Maddeningly, they are usually not prepared to pay for very cost-effective preventative maintenance, either, but that is another story... ]

However for someone fettling their own bike(s) it is arguably of more value to critically assess the nature of any damage and its causes. The reason is that some failure of setup or maintenance (over which you presumably had 100% control) has usually caused the problem, and it is of course essential that you understand what has happened (and why) if you wish to avoid a recurrence.

On the latter point I distinctly recall a post on this very forum from someone who reckoned that Dura-Ace headsets must be rubbish, because he'd wrecked about four of them in short order.... A little critical assessment of the failures would presumably have revealed their true cause, which was (IIRC) excessive preload.

cheers

[Sweep]

The other thing I have found surprisingly useful is to cut the bottom from a drinks can; this shallow recess is good for cleaning/inspection of ball-bearings, and is itself very easily wiped clean.

cheers

Or cleaned tinned fish tins - eg round tuna or small oblong tins that have had sardines and the like in

[Sweep]

past that the same rag gets used for g.p. cleaning of grubby parts where there's no need for inspection nor the risk of contamination, i.e. removing the crud from jockey wheels.

Yes, exactly what I do with the older grubbier ones - under bottom bracket, bits of frame, exposed bits of cables etc etc.

[Gattonero]

The other thing I have found surprisingly useful is to cut the bottom from a drinks can; this shallow recess is good for cleaning/inspection of ball-bearings, and is itself very easily wiped clean.

cheers

Or cleaned tinned fish tins - eg round tuna or small oblong tins that have had sardines and the like in

Or the cap of a GT5 can itself.
Even though, I make it simple and keep the bearings in the palm of the hand with the rag on. Easy peasy.

[nigelnightmare]

Careful the last GT85 tin cap I got had a small hole in it making it useless for cleaning bearings or small parts.

[mercalia]

The other thing I have found surprisingly useful is to cut the bottom from a drinks can; this shallow recess is good for cleaning/inspection of ball-bearings, and is itself very easily wiped clean.

cheers

Or cleaned tinned fish tins - eg round tuna or small oblong tins that have had sardines and the like in

Or the cap of a GT5 can itself.
Even though, I make it simple and keep the bearings in the palm of the hand with the rag on. Easy peasy.

i use discared lild yougurt containers - they are quite shallow and big enough to catch bearings