Suspension Service vs. Tuning

Suspension service replaces wear components inside your suspension and brings it back to state of “working as designed”. Service, especially of components long overdue, will often result in notably improved performance on its own.

Suspension tuning takes this a step further, altering the fundamental performance characteristics of the hardware. Selecting the correct spring rates is the first step to this, but the complex aspect comes with changing damping characteristics. This may involve new pistons, altered cartridges, updated shim stacks, and other hardware changes depending on rider needs. Due to the time involved, suspension tuning is more expensive than a standard service.

Why is it important to service your suspension?

Many bikes only get the bare minimum of service, and dirt bikes in particular are used in harsh conditions every time they leave the garage. Even after riding, dirt and water are often pushed past seals into places they don’t belong with pressurized water. On top of this, aggressive use results in very high temperatures of the damping components. If you are a racer, go hammer out a few laps of your favorite test loop and carefully touch the reservoir of your shock. Now imagine how hot this gets during a two- or three-hour harescramble, or a several hour long desert race. The same thing is happening inside your forks, but the damping chamber is separated from the outer leg by an air/oil gap that prevents you from feeling the heat in most cases.

Operation in this environment means that dirt bike suspension needs to be serviced at more frequent intervals than the same components on a street bike. All suspension, however, will also have internal wear over time due to the various sliding surface interfaces. This is most severe on brand new hardware, where tolerances are tight and surfaces have not yet bedded in, but will occur for the life of your suspension. Even the anodizing inside your shock and fork tubes will smooth out over time, and spring forks in particular generate more debris as the OD of the spring rubs on the ID of the fork tubes. This wear produces fine particles that are picked up and carried by the oil, which as an abrasive as it is pumped through the damping hardware. This debris also embeds itself in piston bands and sliding bushings inside your suspension, causing their friction-reducing coatings to act more like sandpaper.

How often should I service my suspension?

If you are looking for maximum life and durability, it is a good idea to exchange suspension fluid after 10-15 hours on a brand new bike. Following initial break in, Tuned Concepts recommends 50 hour service intervals. These intervals can vary depending on the rider – a high level racer may find that they need a slightly shorter interval, typically due to fluid degradation resulting in shock fade. A trail or dual sport rider may be able to go 100 hours, but beyond this tends to be a risk for accelerated wear if there has been fluid contamination or leakage. We can work with you to understand what the right interval is for you.

My suspension isn’t leaking, do I still need to service it?

Yes, you do. Leakage is the most obvious external issue, but even if the suspension isn’t leaking, the oil inside is degrading as it thermally cycles, and is picking up debris from internal wear. Most riders can feel a difference in suspension performance (particularly the forks) after service, and this is primarily because that embedded debris and seal wear result in significantly increased stiction. That stiction directly impacts ride quality and how much input makes it to the rider through the bars, pegs, and seat.

What does Tuned Concepts replace during service?

Forks receive new seals and bushings, and the shock gets a new seal head and a new piston band. Fresh fluid and a nitrogen charge for the shock are also included. During service, the suspension is also inspected for any wear. Orings, clickers, shock bearings, internal anodizing, etc. are inspected. These are generally not included in basic service cost as they are often not required.

You (or someone else) just serviced my suspension, but after only a few rides, the forks are leaking! What did you mess up?

While mistakes occasionally (though rarely) happen, it is not uncommon to have fork seal leaks if you ride in very muddy terrain. This is especially true if the mud dries on the forks and then the forks are compressed – that dried mud is stuck to the sliders well enough that it can be pulled past the scraper seals on the forks and cause leaks. This is part of why it is so important to keep your bike clean – your suspension will thank you.

The same thing can happen with the shock, though it’s quite a bit less common to have happen within a normal 50-hour service interval. Typically by the time the shock leaks, it is far past due for service.

If my forks leak, do I need a service?

Not necessarily. The forks have two seals – the outer seal is a “scraper” seal that prevents dirt from reaching the inner seal. The inner seal is what actually seals the oil into your forks. Often, you can take a small flat blade screwdriver and slide the outer scraper seal down out of the fork leg. Then you can clean out any accumulated dirt between the seals, and you can use a Seal Saver or similar cut up piece of thin plastic to pull any dirt out from the seal interface.

If your forks have lost a lot of oil, you may need to reset oil level to ensure sufficient lubrication for the internal parts, proper bottom stop function, and proper damping.

This only applies to forks. If the shock is leaking, it will require service.

How do I maximize the life of my suspension between service intervals?

The best thing you can do for your suspension is keep it clean. After you ride, take your garden hose and at least spray off the forks to make sure you don’t leave hardened mud in a place where it will get pulled past the seals. Do not use a pressure washer on your fork seals, it will push water past the seals and into the forks, which will cause corrosion damage.

Mud can pack in behind the fork guards, sometimes these need to be unbolted to be able to effectively clean behind them.

The shock, especially the shock shaft and area between the body and the bump stop, also needs to be kept clean. At the bottom of the shock body, many shocks have a dust cover with some small holes drilled around the outer diameter. Using low pressure water, spray in through these holes. This will clear out any dirt that has packed in around the shock seal head.

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