Properly maintaining your motorbike will not only keep it safe, but it will also ensure that it handles and performs at its peak. While most of us would not hesitate to change the engine oil on our motorcycles once a year, few of us know that the front fork legs contain oil that is constantly working while you ride.
Your bike’s rear shock (or two) also contain oil, but they can’t be maintained without specialized gear
Aside from keeping the oil in your forks fresh, the seals will eventually fail. Here’s all you need to know
How should I care for my motorcycle forks?
One of the most common causes of fork seal degradation is pitting and corrosion on the fork upright bar (or tube / slider) — the seals keep the oil in as the tubes travel up and down in the legs. However, any flaws in the chrome can fracture the seal, allowing the oil to escape. Forks with black or gold nitrogen coatings, for example, do not pit like chrome forks; any damage should be assessed by an expert.
Small blemishes in the chrome can be carefully cleaned using fine emery paper and WD-40, but if the damage is severe, they must be re-chromed or replaced. When re-chroming, it’s crucial to work with a fork repair specialist who understands how critical the tolerances are.
Keep your forks clean, just like the rest of your bike. Don’t be lured to use seal cleaning equipment that slide underneath the seal while it’s still in place – they can force grit into the fork body, where it can get into the damper shims and valve, causing extra damage to the seals. If the dirt seal on top of the fork leg is allowing dirt to enter, it – along with the oil seal – must be replaced.
How long will my fork components last for?
How long your fork seals, bushes and fork guide bushings endure depends on how and where you ride. If you bike in highly dusty regions, over a lot of potholes (or land a lot of ham-fisted wheelies), they may fail in a few years.
The oil has a limited lifespan, and the manual specifies when it should be replaced.
The best method to keep your forks in good working order is to service them. While every 2 years would be great, assuming no problems, every 3 to 4 years should do (unless you’re on track or riding a lot). If you are handy with tools, you can service them yourself.
How can I know if my fork seals and bushes need to be replaced?
The bushes will wear down with time, leaving some movement between the leg and the stanchion. Actually, the fork seals will fail first, and if you’re changing them, you might as well change the bushes as well, especially since they have to come out to get seal out.
When the sealing fail, you’ll notice traces of oil on the fork struts near the dust seal; if there is any, wipe it clean and bounce the forks a few times to make sure it wasn’t just road grime.