Lower leg service tips

Cqc

Hey all, soon going to do a lower leg service on my open bath float RL, and was wondering if anyone who had done a lower leg service before (any fork) had any advice, tips or tricks for me. Thanks

jimothy78

1. Read the service instructions carefully, checking you have all the tools you are going to need (including torque wrench and measuring cylinder/syringes appropriate for the quantities involved).
2. Get everything you will need ahead of time (Spares, fluids, isopropyl alcohol for cleaning, nitrile gloves).
3. Read the service instructions carefully checking you have all the tools parts and fluids, etc you need.
4. Ensure you have a spotlessly-clean work area, and several clean containers to put the parts you remove in/on.
5. Read the service instructions carefully (get the idea yet?)

Cqc

Thanks, but is the torque wrench really so essential?

jimothy78

depends how much of a risk you want to take. Forks are expensive - would be a shame to f*ck them up by knackering something by overtightening and stripping a thread.

Your choice at the end of the day, though.

goytregrit

Set aside about 1 hour for your first attempt.
Get your crush washers and oil from mojo.
Buy the lower leg drift tool, its about £15 I think.
An air line if you have access to one is useful when you clean out the lowers to blow out any dirt.
It can be done quite easily without taking forks off bike if you have a bike stand and then just take bike off stand and turn upside down on floor when you fill the lowers up with oil.
I use a plastic measuring test tube type thing bought from Wilko in their beer brewing section to measure oil and pour into lowers. Makes it all quite simple.

jimothy78

goytregrit wrote:

It can be done quite easily without taking forks off bike...

it can, but use it as good motivation to take forks off and give your headset a bit of TLC at the same time - god knows they need it with the awful conditions we've had lately.

Cqc

What's the point getting new crush washers? Sorry im new to this. Also, what difference does it make if you put more oil than necessary in? Does it make it more progressive or what?

Dirtydog11

Cqc wrote:

What's the point getting new crush washers? Sorry im new to this. Also, what difference does it make if you put more oil than necessary in? Does it make it more progressive or what?

Crush washers will stop the oil leaking from the bottom of the leg, you can sometimes get away
with reusing the old ones.


Some put a touch more oil than reccommended in the top of air spring , it can help reduce dive/bottoming making them, as you say, more progressive.

Yes, I'd say a torque wrench is necessary especially when your dealing with aluminium bolts and shafts, I honestly wouldn't let you any where near my bike without one.

rapid_donkey

I last did this about 2 weeks ago.

When the lowers are off, cycle the damper to make sure you get all of the oil out.

I got a 100ml syringe of ebay to measure and add the oil to my forks.

Oh and dont use an open ended spanner to get the old seals out. Its what fox and all the youtube videos use, but the spanner can mark the inner sealing face of your fork. I used a plastic tyre lever.

And when you fit the new seals, a 32mm or 33mm socket is perfect for making sure they are pushed fully in.

Cqc

Thanks all, I won't be changing the seals as they look in good shape, I'll just be cleaning them and changing the oils, is isopropyl alcohol safe to use inside the lower legs? And inside the uppers too? Thanks

rapid_donkey

IPA is fine to use in the lower legs. I cleaned my lowers in warm soapy water using a bottle brush. Stanchions can be cleaned with some GT85 on a clean cloth.

Unless you already have SKF low friction seals fitted, I would fit them whilst you have it apart .

rockmonkeysc

It's a simple job. The most important thing is cleanliness and being methodical.
Read the instructions, have all tools and materials ready and make sure you use a lint free cloth which will leave no trace behind.
I did my F120R Floats several times and took an hour first time but got down to half an hour without rushing.
Open bath forks are very simple and there's very little you can do wrong.

Cqc

Thanks all so much, one last question, should I clean the inside of the upper legs, eg damper and air spring by squirting IPA up them, or just leave them, also, I've read about 'removing air from the damper' online once it's all put back together, by cycling the fork, but the how would the air escape? Thanks so much so far

jimothy78

Cqc wrote:

Thanks all so much, one last question, should I clean the inside of the upper legs, eg damper and air spring by squirting IPA up them

Unless you strip them down and perform a full serivce, there won't be much "inside" to get at - they'll have some sort of seal at the end, with the rods extending through them. But, yes, I'd wipe down any visible surfaces, before lightly re-greasing.

I've read about 'removing air from the damper' online

Not sure aboout this one - maybe they mean to release bubbles in the oil (the damper unit contains free flowing oil, but it's not full, so there's an air-space above it, and maybe they're talking about bubbles gettting trapped in the damper during servicing?) - never heard of it myself, but cycling the fork certainly isn't going to do any harm, but I'd check the official manual for instructions, not hear-say off the internet.

DCR00

IMO you don't need to replace crush washers every time.

Don't get suckered into buying Fox branded oil. There are plenty of good alternatives that don't cost as much i.e. Stendec

I've never used a torque wrench either. Just use some common sense when doing everything back up again.