hmm how do i service this then ?

noticed the rear end was all over the place after a short ride and as the front forks are sorted via Kias suspension i knew the rear shock was the reason.

so i inquired about a oil change and gas and was told around a £100 and id have to post it so more cost.

so being as im a man who likes to save a few quid where i can i set about doing it myself

first job was how am i going to gas a shock with no schrader valve ?

well ill fit one so got a bolt in valve for £4 from the local tyre firm.
after releasing the oe shock res bolt and releasing the gas i removed the end cap after taking the c clip out (push in the cap and theres the clip)

drilled the hole a little larger to accommodate the valve and fitted it .

then removed the spring and the oil fill screw fron ner the comp adjuster.
#
pumped the disgusting 8-9yr old 26k miles oil out (stinks when it knackered)

and slowly filled with top quality full synth 5w suspension oil.

takes a while to get the air out and i use a syringe to fill .

slowly working the shock up and down its stroke till no more bubbles appear.

then when all the air has stopped coming out i pushed the cap with the new valve in about 30mm as this will remove some more tiny bubbles .

then i fitted the spring and set that to 145mm preload and used a suspension pump (mtb etc) to apply 175psi pressure via the valve .

refitted the shock and its all as it should be again

pic of shock with valve fitted (you can get smaller ones if you want to wait)

cant stress how much a difference new oil in any suspension makes .

yes some will say bla bla bla but in my experience this is what happens when you send it off and pay loads !! new oil and re gas.
and as i now have a valve i can pop to a nearby shop and have it gassed with nitrogen for a tenner if i wanted .

Thrifty fuc#er, well done :thumbup
How did you know what pressure to pump in? and what shop would do nitrogen?
I bet this makes a BIG difference
More pics while work was in progress would have been great.

The Lone Ranger said:

Thrifty fuc#er, well done :thumbup
How did you know what pressure to pump in? and what shop would do nitrogen?
I bet this makes a BIG difference
More pics while work was in progress would have been great.

Click to expand...

all shocks ive done all say dont exceed 200psi

most use 150-175psi so that's what i use on all.

lots of suzuki kawasaki models etc all have a schrader valve and a removable comp adjuster so you can change the oil and re-gas.

if there's no leaks damage on the shock etc an oil change and gas is all that's needed (you dont buy all new fork internals when you change that oil do you ?)
a
as for nitrogen you need a repair shop with the nitrogen machine (nitrogen is more stable as no water in it ) so its better for that reason but not critical on a road bike .

the bike now compresses and rises at the same rate F+R so its as it should be and not like a pogo stick at the rear which the rear was after it warmed up and lost its damping .

i didnt do pics (not that there is much to see) as im not responsible for someone trying this then blaming me for their fook up injury etc !!

anyone with decent tools and ability to service forks change seals etc would have no probs at all doing this:thumbup

but those who ask things like how do i adjust the chain change the plugs etc scare me and id not want then trying this

I see your point with not wanting blame.
A shorter airtank valve could be used (if you want to wait)
My shock has got around 25,000 miles on it, but it doesnt feel knackered (my forks did) and I ride on some quite rough roads. My exhaust header is heat wrapped but even on a short run the shock gets hot, too hot to keep hold of.
If I felt like doing this I have a big compressor and could pass the air through a couple of water traps, good enough for spray painting.
I wonder why your shock lost its damping and mine seems alright at roughly the same mileage?

id say your shock oil is well passed its best at 25k as it goes through serious heat cycles even with the wrap !!

have you tried bouncing it up and down when its hot?

mine seemed worse as the forks are superb with the kias revalve set up etc so showed it up .

you need a pump like this for the pressure which is what i use so you can remove the valve and not lose the pressure as only a small amount of air is used .
http://www.ebay.co.uk/itm/Raleigh-M...kePumps_SR&hash=item2568689251#ht_1804wt_1270

and a small valve like this would be fine but i wanted it now and no one stocked one like this local so got the large one .

http://cgi.ebay.co.uk/ws/eBayISAPI....gory=21669&_trksid=p5197.c0.m619#ht_813wt_905



some info here on rebuilding a sachs shock (note this one has a valve fitted !! all the things here are same as i did bar total dissemble as not required on mine.
you can see how the end cap comes out for reference .

http://www.gasgasrider.org/Sachs_Rear_Husky_610.pdf

well i gave the bike a good ride out to see how it works with the new oil etc.

its cold here at around 5deg but after a 40mile ride i popped the shock pump onto the valve to check the pressure while hot.

the reading was 192psi hot so i dropped that to 160psi cold instead of 175psi .
this is the pump i use
http://www.ebay.co.uk/itm/Raleigh-M...kePumps_SR&hash=item2568689251#ht_1804wt_1270

completely different bike now as the rear is now under control

thing i like about being able to change oil etc is i can use different grade oil ie 10w F+R or 5w which im using atm with only a bit of work to change .
so harder setting or on the softer side as it is now for road.

set the F+R rider sag at 32mm and im just a tad stiffer on oe settings.

ive got the shock at the lowest setting on the adjuster and forks are 3 rings showing .
i may well alter these as i prefer quick steering even though its quite quick now with my 11"10" weight.

its too cold to go pushing the bike but i think it will be one of the best handling bikes ive owned and ive had rather a lot

grow on you these millies

Thanks for the post, I think I might try it myself.
One question, how do you know how much fluid to put in ?
kev

with the cap off (bit the valve will be fitted too)you will see inside the chamber there is a piston which presses on the oil.

using syringe which i made a seal for using a little rubber pipe pressed into the bleed fill hole (small screw at the base of the expansion chamber) i forced oil in until the piston was about 30mm from the chamber top .

hold it so all air rises to the bleed valve .

then pushed it back so it was about 50mm from the top of the chamber .

that forces any air out that might be left and then you pop the bleed screw back in .

fit the cap with the new valve and add 160psi job done .

its up to you what oil weight you use as i used whats in my forks so 5w front and rear (so same weight oil at each end)

im about 12stone kitted and this seems to work well with 5w full synth low foam oil .

if it all goes wrong you can get the shock done at a suspension shop (im just not paying for someone to change the oil) at £75 an hour

meant to say when you remove the cap the piston will be where you want it and mine was around 50mm from the top but i over fill then use the piston to push air out etc.

hth

i thought that there is the nitrogenum gas under the pressure not a normal air in the reservoir...
do you think that a tyre valve will hold 200 PSI long enough?

theruck said:

i thought that there is the nitrogenum gas under the pressure not a normal air in the reservoir...
do you think that a tyre valve will hold 200 PSI long enough?

Click to expand...

A Schrader valve can be used in high pressure hydraulics with far greater pressures than those found in a shock absorber so I would think so. And worse case anyway is that it will need regassing more often. It won't explosively deflate like a tyre would anyway as the only point for the gas to leak is the valve.

theruck said:

i thought that there is the nitrogenum gas under the pressure not a normal air in the reservoir...
do you think that a tyre valve will hold 200 PSI long enough?

Click to expand...

According to Wikipedia, air contains 78% nitrogen. It also says that it typically contains 1%-4% water vapour and thats the part you could do without in your shock.

the tyre vale for a push bike will take 200psi and as above


if you dont want to do this mod DONT DO IT simples

you can get it done for you for £100 plus post etc

OK, just started doing this tonight.
I used Putoline HPX 10 and filled it exactly as looner instructed. It took a bit of patience and wasting some oil to get all the air out.
I havent pressurised it yet because I have ordered one of these valves LINK TO VALVE click the thread on the bolt that seals the cap is 1/8"bspt and I wanted a valve that just screwed in, I don't mind waiting. There was a minimum order of 2 so I will have one spare if anyone wanting to do this wants to buy it.

The Lone Ranger said:

OK, just started doing this tonight.
I used Putoline HPX 10 and filled it exactly as looner instructed. It took a bit of patience and wasting some oil to get all the air out.
I havent pressurised it yet because I have ordered one of these valves LINK TO VALVE click the thread on the bolt that seals the cap is 1/8"bspt and I wanted a valve that just screwed in, I don't mind waiting. There was a minimum order of 2 so I will have one spare if anyone wanting to do this wants to buy it.

Click to expand...

nice one you will be pleased with the result and now you have a shock you can work with:thumbup

I used PTFE on the thread.

The Lone Ranger said:

I used PTFE on the thread.

Click to expand...

top job but a bit windy up your way to test:roll

that's the valve i wanted to use but i just dont wait lol.

so no need to make the hole bigger fitting that either:thumbup

Nice job will be servicing my shock with this excellent info gr8 stuff ...........now just to sort my bloody lights out............

Hi guys and gals, anyone done this mod to a Ohlins rear shock, i'm guessing it would be just the same ?.

Warms said:

Hi guys and gals, anyone done this mod to a Ohlins rear shock, i'm guessing it would be just the same ?.

Click to expand...

ohlins is already a serviceable shock bud its the sachs that needs a valve to re-gas

but id get it done via ohlins service shop for perfect result :thumbup

ohlins forks need service more regular than the showa items too so get them all done together for a perfect ride:thumbup