The bits you don't see

 Perhaps just two bottles, each containing a small quantity of oil. You're not wrong of course, but had you realised that dirty oil is the total contents of a shock absorber after one years use, and the clean oil is the quantity that will replace it. The service schedule on a car may be 10,000 miles, but that is typically five litres of oil, most sitting in the base of the sump ready to be used as the engine pumps it around. A shock absorber uses all the oil on a full stroke, changing compartments flushing through a shim stack. It goes through cycles between hot and cold, it needs all its qualities to perform its core function. Imagine each full stroke of the shock absorber moving such a small quantity of oil with every movement, and the big harsh bumps moving virtually all the oil as it circulates and blends as a dirty mess, losing its qualities to become less of a suspension fluid, and more of a weak dirty liquid with no damping qualities. As you would by now have figured, it wont last too long, yet so many people don't have a shock absorber serviced, and miss out on the plush action a well serviced shock absorber should give. You may also notice, the dirty bottle has less oil, part due to breaking down the structure of the oil, and part due to seepage. It may have taken a few months to reach this level so no trace of oil would be seen as a puddle on the floor, but the air space created can fill with water from condensation, power washing or rain ingress, or if dry air, it would be a percentage of the shock absorbers stroke that was ineffective. As a minimum, SWB recommend at least yearly servicing of motorcycle shock absorbers, and racers more frequently.

This state of the art piece of equipment is designed to evacuate all air from a freshly built shock absorber, creating a vacuum within the chambers, checking for and leakage before cycling fresh clean suspension fluid in the shock absorber. 

It cycles oil, removes any suspended aeration from the oil, or more commonly known as 'bubbles'. With any fluid, shake it and the fluid mixes with air, air can compress, oil cannot. Our machine cycles oil, removes all air bubble and pockets from the fluid before charging the shock absorber with fluid.

Old practices used to depend on air bubbles making their way to the top of the bleed port, or chamber, probably only dependable if left 24 hours, and then not evacuating all trapped bubbles or pockets. This system means a shock absorber can be fully, and totally dependably bled in just 20 minutes, with all air removed as it creates a vacuum and sucks the filtered pure fluid into the shock body for the purest possible shock bleeding to take place. The consequences of aeriated oil are 'frothing' or 'cavitating' which will reduce effectiveness, thin oil as it friths and remove effectiveness of the damper. Air also condensates as shock bodies are not thermally broken, condensation can then turn to rust if it sits trapped between the shim stack. Technical? You bet!

The contents of one fork leg can be seen here. Metal fragments and dirt suspended in the oil have consequential effects on the damping provision of the whole sweep of the forks travel. Left to settle, it is evident these fragments will circulate in suspension within the fluid. 

The fork that this oil came from had been serviced by others, a cheap £50 service! We have no doubt the oil had been changed, maybe the seals also, yet question if the fork had been separated, flushed, inspected and corrected if ingress should have any damaging effect. Just one fragment of this contamination suspended in the oil could be as detrimental as one full click on the compression adjusters, and the same again on the rebound. Have no doubt, that there are cheap services that merely change the oil, and then a SWB service, where each component is removed, inspected, cleaned and put back to give true damping.

We urge anyone to consider that a £50 service is not a service. Consider the time involved, at around an hour, consider the oil costs at over £10. Seals and dust seals another £20. Ask yourself if you do get a true service from the guy down the road who fixes bikes, or do you just get oil and a sticker on your fork legs that suggests it was serviced. We feel confident you will understand, there is no such thing as a £50 service. If the contaminates are left in the fork, you merely wasted £50.