How often do you really need to service forks and shocks?

Question

According to manuals, forks and shocks have to be serviced regularly. For example, rockshox forks have 50-hour and 200-hour service kits/instructions.

On one hand, I know people who swear by these values, and they obviously never had any problems. Servicing can hardly be bad for your bike. But its also costly and annoying. I dont wanna do it every 50 hours of riding, that would mean every 6 weeksor so in summer!

Rockshox obviously wants to sell these service kits, and they also want to err on the conservative side in order to avoid claims like "Ive done my service regularly according to rockshox manuals but still my fork is damaged". I know many friends who are riding their bikes for years without giving a crap about service, and their bikes seem to work well too.

Obviously this has a lot of variables: rider weight, conditions, how hard you ride, and "luck". All those aside, I was wondering if there are experienced mountain bikers here who can give me their opinion. Thanks!

Answer 1

Suspension needs to be serviced in order to maintain low levels of friction, maintain proper sealing of air and oil, and clean away dirt and other foreign matter. This results in consistent and smooth performance of the spring and damper, while also keeping the fork/shock's mechanical condition in good shape for the longest possible lifespan.

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Some factors to consider:

• One’s sensitivity and attitude towards changes in performance:

  • Some people are more sensitive towards changes in their suspension performance than others. For some, a small pressure adjustment like 2-3psi or a click or two of damping is a noticeable difference. These more discerning riders will need to service their suspension more often as the depletion and breakdown of oil results in more friction. As the damage gets more permanent (ie scratched or worn parts or leaking seals), some riders may not notice this either. Sometimes, riders are unaware that their fork even needs servicing as they don't remember how it performed fresh after a service and just think "it has always been like this" etc.
  • Additionally, some riders have a "just ride your bike" attitude and don't really worry about things such as marginally increased friction or air loss rate or damping performance etc.

• Local riding conditions:

  • If your trails are always wet and muddy, service intervals will need to be shorter due to the increased possibility of water ingress and sticky mud coating all surfaces. Dry and dusty conditions may also warrant additional attention due to the abrasive dust everywhere.

• Personal maintenance regime + general attitude towards maintenance and mechanical work:

  • Not everyone has the time or energy to maintain their suspension by the book. Again, some riders adopt the "just ride your bike" mentality and neglect to perform preventative maintenance until something explicitly breaks or fails. This is often evidenced through other systems on their bike(s) too, eg. drivetrain.

• Riding style:

  • Someone that rides fast and aggressively places higher loads on their suspension, while intuitively suggests shorter service intervals. Large impacts create high pressures in both the spring and damper, so sealing will be more important. Rider weight comes into play here too.

• Quality of service:

  • Servicing according to the schedule is great, but an improperly done service could carry issues too. Just because a rider "services" their suspension every 50h or whatever doesn't necessarily mean that the service was done correctly. For example, if a rider mistakenly injects the bath oil into the shafts instead of the lower legs, oil will be in the wrong place. Careless work could also result in scratches on sealing surfaces etc that could degrade performance too.

You can probably push that to new seals every 150-200 hours, but definitely change and replenish the bath oil every 50-100h. You only have ~5mL of oil in each leg total for lubrication, and that really isn’t a lot when you spread it out over so many rides. The air and oil seals aren't anything special, and I highly doubt any other comparable application of O-rings in industry mandates such short service intervals. The wiper seals are a different story, but my opinion is that frequent oil changes should be able to remove a good portion of any contaminants and extend service life a little.

In my opinion, the primary cost in suspension servicing isn’t really the cost of the seals and oil themselves. A basic seal kit is like $20 and covers most of the dynamic seals. It’s more the labor and skill cost of taking enough time to properly clean and rebuild such finely made assemblies. I’d reckon suspension is the most accurately and precisely made area of your bike, and hopefully you treat it as such. It's a lot of delicate work that has to be kept surgically clean.

Answer 2

My guess is most shocks get neglected till they are stuffed, often resulting in the need to buy new ones or writing off the bike.

A basic service can be done yourself and costs a bit of time. It costs next to nothing; a $10 bottle of fork oil will last forever, a bit of iso prop for cleaning, and a bit of time. It is all that is needed to prevent premature wear of the fork.

A full service replacing seals, requiring manufacturers seal kits, is needed less often if the basic servicing is done. The risk of skipping full service is, because such small amounts of oil is involved, a leak could lead to loss of oil, so for the cost of a few O-rings, it's not worth the risk.

Anecdotally - I had to replace a set of forks that were serviced poorly (by a shop, not me) - not enough oil was used, resulting in worn out stanchions, so regular fork service is not a zero-risk option.

How often depends on the riding conditions, your tolerance for having $1000 shocks performing like $100 shocks, and how much you like the idea of buying new shocks for an otherwise serviceable old bike.

Manufacturer intervals are probably very conservative, so you can probably get away with few services, but if the reason for not servicing is cost, learn to do the basics yourself, and get a shop to do the full service if that is beyond you.

Answer 3

I'd say it depends on the abuse. I think riders that let a layer of gunk mark their max compression point should probably service it every 50 hours.

But I dry wipe my stanchions and rear shock, spray with stanchion spray, bounce the shock once to push up the last ring of dirt, and then wipe again. I'd say I went 200 hours instead of 50 hours for my rear shock. I felt a little iffy on that since it's inverted and the oil has an easier time coming out, but a friend that went even longer gave me some faith. Honestly I think the can oil all weeps out pretty quickly anyway and I'm adding the spray before every ride.

I think my front shock is probably closing in at 250 hours and I've never done anything other than my spray routine and it's still holds air and works like new. I'll probably let it go even longer.

In the end, my 3 minutes of maintenance per ride probably the same as the time it takes to do the 50 hour service. I suppose eventually the seals will need to be replaced, but I will say at 200 hours, the seals I removed from the rear still looked really good.

Am I recommending this practice? No necessarily. But it's certainly evidence of the possibility of 50 hours being conservative by the manufacturer.

Answer 4

My opinion is that a bicycle's suspension system is arguably the most active and stressed areas on the bike. As such, a little regular attention is warranted. Oil bath changes are straight forward with much online help. Oil change and washing out or replacing the foam rings should be done 2-3 times per year.

Replacing seals and o-rings via a service pack can maybe stretch to every year and 1/2 IF you're doing oil changes and re-lubing seals and o-rings with slick honey or equivalent in conjunction with oil changes. Slick honey will keep the seals and rings lubricated and well conditioned, enhancing their performance.

Stretching the annual full service to every 18 months (while performing cleaning, oil changes and fresh grease every couple of months) can make sense for many riders. In 3 years you've invested in 2 service kits and 1 bottle of oil. That's a very reasonable cost for such a hard working aspect of your bike.