Rear shock rebuild

[Rupe]

Got my bike in pieces at the mo and was looking at the rear shock thinking I wonder when I'm ment to change the oil etc? When I do my forks they always fell better.

So, for your average weekend rider how many hours are they good for before you have to chage the oil? What else do you have to change? What weight Oil do you use? And how much does it cost to get them filled with nitrogen?

[Danger]

50 hours if your just trail riding, 30 hours if your racing or riding in a lot of mud. I've seen figures of 17,000 compression cycles on one lap of your average MX track so add 17,000 rebound cycles and you can see the demands placed on the rear shock.
I only use SD1 shock oil, its formulated to work with the demands a shock puts on the oil, not the cheapest but the best I have access to. Some clown on here mentioned he used 5 weight rock oil lol, each to their own I guess.

Crazy to take a shock a part and not replace the seals, and most of those 2007 Showa's need a shaft bushing as well. Many will not charge a shock that has not been built by the person doing the recharging but the ones that will seem to charge about $20.00 in my experience.

So at least new oil and dust seals, the shaft needs to be checked for rust and pits, many bikes that have been on Muriwai beach have rusting shafts that will chew out the seals when the bike is bottomed, the bump rubber should be ok if the bike has not been ridden very hard but it needs to be checked, they rot from the inside, and the bladder needs to be replaced if worn or distorted, probably ok in your case unless the shock has lost some oil at some stage or not been serviced properly.

[Rupe]

50 hours if your just trail riding, 30 hours if your racing or riding in a lot of mud. I've seen figures of 17,000 compression cycles on one lap of your average MX track so add 17,000 rebound cycles and you can see the demands placed on the rear shock.
I only use SD1 shock oil, its formulated to work with the demands a shock puts on the oil, not the cheapest but the best I have access to. Some clown on here mentioned he used 5 weight rock oil lol, each to their own I guess.

Crazy to take a shock a part and not replace the seals, and most of those 2007 Showa's need a shaft bushing as well. Many will not charge a shock that has not been built by the person doing the recharging but the ones that will seem to charge about $20.00 in my experience.

So at least new oil and dust seals, the shaft needs to be checked for rust and pits, many bikes that have been on Muriwai beach have rusting shafts that will chew out the seals when the bike is bottomed, the bump rubber should be ok if the bike has not been ridden very hard but it needs to be checked, they rot from the inside, and the bladder needs to be replaced if worn or distorted, probably ok in your case unless the shock has lost some oil at some stage or not been serviced properly.

Thanks, pretty much answers all the questions. The bike doesn't come from aucks so prob hasn't seen much beach riding if at all, and the shaft appears good (would inspect more if apart). To be honest the shock seems fine to me, but I have never had a freshly service rear before so might do it while the bike is apart, not sure yet, cost does come into it.

[Robert Taylor]

Thanks, pretty much answers all the questions. The bike doesn't come from aucks so prob hasn't seen much beach riding if at all, and the shaft appears good (would inspect more if apart). To be honest the shock seems fine to me, but I have never had a freshly service rear before so might do it while the bike is apart, not sure yet, cost does come into it.

Greg has many excellent points and the figure of 17,000 compression cycles per lap is from Ohlins.
I do dispute the service intervals because at 30 hours the shock has long since deteriorated in performance. 20 hours is a more correct figure. I know that is not music to most peoples ears! As the oil deteriorates it also loses its lubrication properties and that accelerates internal wear. The worst examples are the lower grade shocks that are not so well hard coated internally, leave the oil in too long and the wear rate increases rapidly. Shim stacks and bypass orifices really stress the molecule chains, the fact is shock oil is subjected to an enormously difficult task.
And dont use cheap oil and cheap tecnicians! Greg is correct about using a high quality oil but I challenge his assertion in that we have even better oil, Ohlins oil. And yes its probably more expensive than Gregs favoured oil, but we still sell lots of it.

[Danger]

I do dispute the service intervals because at 30 hours the shock has long since deteriorated in performance. 20 hours is a more correct figure. I know that is not music to most peoples ears! As the oil deteriorates it also loses its lubrication properties and that accelerates internal wear.
And dont use cheap oil and cheap tecnicians! Greg is correct about using a high quality oil but I challenge his assertion in that we have even better oil, Ohlins oil. And yes its probably more expensive than Gregs favoured oil, but we still sell lots of it.

I don't dispute what you have said Robert but like you say, most people don't want to hear it, or can afford to do such frequent services so we can only make recommendations based on experience then leave it to the customers to make an informed decision as to their service intervals. I'm sure you carry more cred than me so your less likely to be questioned when you mention 20 hours.
Same goes for forks and as Rupe has said they always feel better after an oil change, however they should have more than just the oil changed during a service which the home guy will not be aware of, or do. My sponsored riders have these service intervals but the average customer can not afford to have the services done so often.

[Katman]

Some clown on here mentioned he used 5 weight rock oil lol, each to their own I guess.

Care to elaborate?






(About the Rock Oil - not the clown).

[Robert Taylor]

Care to elaborate?






(About the Rock Oil - not the clown).

Quoting damping oil viscosity in weight eg 5 weight is a nonsense in itself as it is barely indicative of flow rate. For example 5 weight Silkolene has the same approximate flow rate as 10 weight Maxima. Centistroke rating at 40 degrees celsius is the only accurate scale of comparison. Here at CKT we only use the centistroke scale, SAE viscosity ratings are not on the radar screen and should only be used for what they were scaled for, engine oils.
And I agree with what I think Greg was intimating, there are better suspension fluids than Rock oil.

[barty5]

Got my bike in pieces at the mo and was looking at the rear shock thinking I wonder when I'm ment to change the oil etc? When I do my forks they always fell better.

So, for your average weekend rider how many hours are they good for before you have to chage the oil? What else do you have to change? What weight Oil do you use? And how much does it cost to get them filled with nitrogen?

So do tell me where are you going to send your shock for rebuild????????????

[Rupe]

So do tell me where are you going to send your shock for rebuild????????????

I have the manual, so like everything else I'll try myself. Just the nitrogen I couldn't do myself. Wanted to see how much it would cost me for parts, then work out if I can afford to do it while I rebuild the top end.

[CookMySock]

I have the manual, so like everything else I'll try myself. Just the nitrogen I couldn't do myself. Wanted to see how much it would cost me for parts, then work out if I can afford to do it while I rebuild the top end.

Good on ya. The tricky part will be vaccuming all the air out and letting it suck oil in.

You could just pump it up with dry compressed air, rather than nitrogen.

Cue the purists pulling the ideas apart instead of contributing..

Steve

[Reckless]

Most of us would only get the Shocks done once a year and many would have never even had it out I would guess?? Fork oil change probably done more often but not the rear shock and not a revalve on the front.
20 hours Rob that's not on the radar for most of us trail riders especially if we are paying for 2 or more kids bikes as well. I'd ride 2-2.5 hours per time (the Ktm only records riding time when the front wheel is turning so no cheating here either) so I'd have the shock out every 8-10 rides. I've done 32 hours so far this year that puts me on a shock/fork rebuild 3 times a year ish? Even at Gregs 30 hours, I'm thinking 10 hours after its due I must get that done! I dunno if I'm typical of the average trailrider that rides most weekends and does the odd trailblazer and GNCC, but I would suspect I am. If your racing and sponsored 20 hours is a goer but for us I would suspect even 30 is not achievable/affordable. Our loss I agree but that's life!

Oh Rupe if it where me I'd get Danger (as he's local and good) to do the shock and forks, the first time, its well worth the few hundred to get the expertise and setup that comes with it! So I'd put it back in an put up with a less than perfect bike till you can afford to look at your springs, fork and shock. If your springs are ok for your weight you can get it done much sooner! I could only afford new front/rear springs and a front fork revalve but the bike is beautiful now! Might get the shock done when I get the fork oil replaced, twice a year for forks and once for the shock is max i can handle, and prob more regular than most. At a 32 hours so far this year that puts it on 30-40 hours for the forks, done 9 hours since I had them done and the bike personally setup for me at Dangers work! That's what I did, and the bike is much better for it I reckon, waste of time doing one end and not the other.

[Rupe]

Most of us would only get the Shocks done once a year and many would have never even had it out I would guess?? Fork oil change probably done more often but not the rear shock and not a revalve on the front.
20 hours Rob that's not on the radar for most of us trail riders especially if we are paying for 2 or more kids bikes as well. I'd ride 2-2.5 hours per time (the Ktm only records riding time when the front wheel is turning so no cheating here either) so I'd have the shock out every 8-10 rides. I've done 32 hours so far this year that puts me on a shock/fork rebuild 3 times a year ish? Even at Gregs 30 hours, I'm thinking 10 hours after its due I must get that done! I dunno if I'm typical of the average trailrider that rides most weekends and does the odd trailblazer and GNCC, but I would suspect I am. If your racing and sponsored 20 hours is a goer but for us I would suspect even 30 is not achievable/affordable. Our loss I agree but that's life!

Oh Rupe if it where me I'd get Danger (as he's local and good) to do the shock and forks, the first time, its well worth the few hundred to get the expertise and setup that comes with it! So I'd put it back in an put up with a less than perfect bike till you can afford to look at your springs, fork and shock. If your springs are ok for your weight you can get it done much sooner! I could only afford new front/rear springs and a front fork revalve but the bike is beautiful now! Might get the shock done when I get the fork oil replaced, twice a year for forks and once for the shock is max i can handle, and prob more regular than most. At a 32 hours so far this year that puts it on 30-40 hours for the forks, done 9 hours since I had them done and the bike personally setup for me at Dangers work! That's what I did, and the bike is much better for it I reckon, waste of time doing one end and not the other.

Yeah just a weekend rider too, so It's not viable to be doing suspension rebuilds so often. Too bad really if it would be better performing if it was done every 20hrs or so.

Mike Cotter set up my suspension on my new bike, so thats my starting point to experiment from. And the fact that I was trying to work out if I can afford just the parts means It'll be me that does it, or no one.

[Robert Taylor]

Yeah just a weekend rider too, so It's not viable to be doing suspension rebuilds so often. Too bad really if it would be better performing if it was done every 20hrs or so.

Mike Cotter set up my suspension on my new bike, so thats my starting point to experiment from. And the fact that I was trying to work out if I can afford just the parts means It'll be me that does it, or no one.

Do yourself a favour and get it done proffessionally by Greg. Those who do such work day in day out ( and are proffessionally equipped to do so ) have an eye for detail, know what fails / wears most etc.
I quoted the ''correct service intervals'' as a matter of the reality and what is most technically ideal.

[flyingcr250]

Do yourself a favour and get it done proffessionally by Greg. Those who do such work day in day out ( and are proffessionally equipped to do so ) have an eye for detail, know what fails / wears most etc.
I quoted the ''correct service intervals'' as a matter of the reality and what is most technically ideal.

its probably cheaper in the long run to get a pro to do it, atleast then youve got someone to blame if it fails..... ha ha ha

[Rupe]

Do yourself a favour and get it done proffessionally by Greg. Those who do such work day in day out ( and are proffessionally equipped to do so ) have an eye for detail, know what fails / wears most etc.
I quoted the ''correct service intervals'' as a matter of the reality and what is most technically ideal.

If you pay for it,

I was wanting to work out what the parts would be needed and the cost. Then see If it's something I could afford at the mo, which greg answered straight away. Thanks