Is rust proofing recommended for motorcycle?


Premier Member
IBR Finisher
I'm a big fan of Fluid Film, I've used it on the underside of my pick up for years applying each fall since new, 5 NY winters, zero rust.

However I've not used it or similar like ACF50 on my bikes. I don't ride if salt is on the ground if I can avoid, and if I do, I wash it off right away.

That being said, it can't hurt to apply some of the tried and true options if your going to winter ride or live on the coast in the salt air. However for general riding seasons that see rain but no salt, I don't see a need to rust proof a modern bike.
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Premier Member
IBR Finisher
Most modern bikes don't have the same kind of underbody that auto rust inhibitors are used on. I don't think it's an apples to apples comparison. I don't think LA California is particularly subject to sea salt corrosion unless you own a beach house and ride on the beach itself. The de-icer used in CA is corrosive, if I recall correctly, but I never had significant issues when I lived in OR and rode the western states a lot all year long. And most of the under body areas on bikes are plastic now, unless you ride a HD.

@Jonnyp - Yes, we can get ACF50 in the US from several sources - Amazon

An article from ACF about motorcycle use - LINK


IBA Member
Thanks Eric...

A lot of us over here in the UK use ACF50 as we salt our roads through the winter. If you can get a good coating of ACF50 on in November and keep it there until March it will really help protect the bike. I’m even starting to keep it on all year now. Especially on the underside of the engine...



New Member
I would think that the bike would be exposed enough that a good cleaning every so often should be good enough. However, for the electrical system to perform properly for the life of the machine, I would strongly servicing all of the non-sealed electrical connectors as soon as practical. That means removing body panels and fairings to gain access to them.

The reasoning is that the pins within the connectors need to be isolated from the oxygen in the air in order to inhibit development of corrosion, which adds resistance to the circuit. In some cases on a marginal connection with a lot of current flowing, the oxidised corrosion resistance can be so great that the heat generated will add to that resistance, to the point of a thermal run-away resulting in burned insulation and electrical shorts. The grounding bus (spiders) in the 2nd Gen. Yamaha FJR platform comes to mind.

Some people swear by the application of ACF50 to these connectors. In my experience I found that ACF50 tends to wash out and needs reapplication after a couple of years. My preferred medium is silicone dielectric grease injected into the female pin of every connector, sealed or not. Being a high temperature grease instead of an oil, it will stay put and continue isolating the metal surfaces for the life of the bike.

While you’re at it, put a smear of dielectric grease on the rubber grommets and bullet points for your bodywork when reassembling. The next time you need to remove a panel it will go easier.


Premier Member
IBR Finisher
I've had a couple motorcycles. Lived and rode in FL, MI, CO, NM, PA[ Carlisle actually - the here's yer salt capitol of PA], the Eifel Mountains of Germany and Sembach Germany - not to mention riding all over the U.S. and Canada. Had bikes in some pretty harsh winter areas and rode when it was even remotely - even stupidly - possible.

I have never had a bike that wasn't easy to keep up and prevent rust on - except a 1946 Simplex I had for fun.

Personally, I wouldn't wast time nor money on any kind of rust proofing on my motorcycles [currently down to two].


Premier Member
It really depends where you live. If cars tend to rust in your area and you ride your bike in winter, yes I would be concerned. Even if your bike has a plastic under fairing there are metal parts inside that will get wet and corrode.

In the FJ-09/Tracer community, many UK owners report issues with a pipe on the oiler cooler that cracks and leaks due to corrosion, but the issue is unheard of in USA and Canada, even from those living in the upper midwest and northeast. ACF50 is the popular recommendation for UK riders.

I live in Oregon, where winter weather is pretty similar to UK weather, but maybe a couple of degrees warmer. I ride year round but don't have corrosion issues because they don't use salt or any other deicers on the roads. On the rare, rare occasion where we get ice the state just dumps sand on it, or they tell everyone to stay home until it melts.