Cleaning and lubing XT rear mech

portland_bill

I've been having a few minor problems recently with my rear mech sticking and not shifting properly and I know it's because I've neglected to maintain it properly and it's caked it crap.

I've taken it off the bike (still attached to cable) and I'm going to try and clean the jockey wheels and joints as best as I can.

I just wanted to know the best way to do this and what lube (if any) I should use to grease the wheels back up before I put them back in. A mate of mine suggested just dumping the entire mech in a bowl of petrol overnight to dissolve the grease and crud off it, then clean it up by hand and lube it, but I'm not sure dumping it in petrol can be that good an idea. Am I right or is he?

cooldad

I wouldn't.
Just clean it with soapy water, rinse and lube the jockey wheels and pivots with some light oil.
Easiest to remove the jockey wheels first.

portland_bill

Just to check, the upper jockey wheel bolt is at some point under tension. Is it just a locatable spring behind it? I'm just wary about undoing things under tension to have them suddenly release and fire small parts all around the room never to be found again.

As you can probably guess, it's happened before. :roll:

cooldad

The jockey wheel is not under tension, just undo the bolts and remove. The jockey wheels and outer cage will be loose.
Jockey wheels need to go back correctly though.
They are marked upper and lower, and the upper one has a ceramic bearing.
Bit of drgreaser might help if it's really bad, but don't soak in petrol.

portland_bill

Cheers bonnie lad!

.blitz

Portland Bill wrote:

I've been having a few minor problems recently with my rear mech sticking and not shifting properly and I know it's because I've neglected to maintain it properly and it's caked it crap.

It takes a lot of crap to mess up a rear mech. My guess is cables.

anjs

Also the sticking could be due to your cables. Would also give them a clean relube and replace if necessary

portland_bill

I'm pretty sure it's just crap. It's usually after just sticking the wheels back on the bike after I'd had it in the boot of my car. The mech doesn't always spring back in like it should and just needs a bit of light encouragement.

To be fair, I can hear the crap quietly crunching and grinding inside it, so it definitely needs a good clean out.

It could well be the cables too like, but it still needs a clean. Guess I'll find out after I've cleaned it.

portland_bill

I should point out the bike is only a couple of years old and hardly got any decent use at all last year so in a way it's probably still bedding in. The cables should still be nearly new but might need a drop of oil and a tweek.

How do you guys rate those cable oiler things that clamp around the top of the cable?

.blitz

Portland Bill wrote:

The cables should still be nearly new but might need a drop of oil and a tweek.

No, they won't

Along with BBs and headsets, cables are one of those areas where MTB manufacturers fit the very worst of the worst. Shift into the biggest cog at the rear, then shift all the way down without turning the cranks. You will have enough slack in the cable to unhook it from the guides. The inner cable should slide in-and-out of the outer with virtually no friction. Really. The slightest bit of drag will mess up the shifting.

Lubing them makes it worse the lube just attracts dirt. What you are aiming for is sterile, maybe just a little bit of household polish on the inners.

I know how that reads but I have been there and got the t-shirt etc

cooldad

Oiler things are rubbish.
As blitz said, stock cables tend to be rubbish and rust inside. Fit some decent stainless steel ones, and clean (or replace - can find for a few pounds, including outers on Ebay) regularly.
Makes a big difference.

1mancity2

Replace the cables rather than trying to lube.

Shackster

The best option for cables is the Gore Tex Ride-on system. I've had them on my hardtail since about 1997 and never had a moment's trouble with them, still as smooth as when first installed - shame I'm not.

Another option for keeping the crud out is to run the outer all the way from the shifter to the mech, so none of the inner is exposed (by-passing the cable stops, you have to zip-tie the cables instead). Bit heavier, but v. low maintenance. I've done this with brake cables too in the past.

I've got an XT mech on my new Canyon and after the recent, very very muddy BHF south downs way ride, the upper jockey wheel was siezed. I took it out and popped the seal off the bearing with a craft knife - full of crud. No amount of lubing from outside is going to sort that, although it might get it moving, for a while. Easy enough to clean, re-grease and it's good as new now. Also did the lower wheel, which was virtually clean by comparison; I think the liquid mud got forced into the top one under pressure.

Both jockey wheels had caged ball bearings.

portland_bill

Cheers for the advice guys, I'll have a look online at some new cables. From what you're saying I might as well do them anyway.

.blitz

SP41 outer cable is £3-4 metre, ferrules are 50-70p each. You can re-use your existing inners if you clean them with wire wool & WD40 but in the long term some stainless inners or a sealed system as described above is the way to go.

Or you could go SRAM with full outers and not do any cable maintenance or make any adjustments in 6000+ off-road miles

cooldad

I wouldn't spend stupid amounts on cables. Just stainless and change regularly. (as soon as shifting gets a bit iffy or stiff)

portland_bill

@cooldad, since I can barely make out the lines on the page I keep reading your posts as always finishing with "I don't do smilies."

diy

Not all gear cables are the same thickness, probably worth buying a kit rather than inners and outers separately.

I highly recommend SRAM flack jacket if you can't go full outer. But full outer is the way to go if you ride in bad conditions.

but wiping the inner and blasting wd40 or tf2 through the outers oftens cleans them up nicely.

cooldad

Or these are good and pretty cheap.
http://cgi.ebay.co.uk/FIBRAX-Uni-Stainl ... 3099991613