Forks oils have always been subjective there isn’t a proper standard to them and people get confused about what’s what which is fairly normal and happened to me as well but all it takes is a little bit of research which I did and here are some basic concepts on what kind of substitutes you can use for your forks oil as some of them are very expensive for no apparent reason and
The purpose of using forks oils is to lubricate the viper seals and o-rings on the bottom but we also have to consider the viscosity index of the liquids at varying temperatures as well to mark it as a good alternative
To simplify things we are looking at 2 things in a fork oil
- Liquidity
- Viscosity index at different temperatures
These values can be achieved with additives like an additive to increase the liquidity of mineral oil but that will decrease the viscosity index and vice versa so you can basically use different things in your suspensions such as mineral oil (not DOT fluid or anything) but if you dont know the properties of that liquid you will most likely mess up the damping (plush) of the forks.
Best Fork oils Substitutes :
Before getting into that make sure that you always check some things the temperature is the key here because you can get away with lubricity and you will know about that when you ride your bike but if the temperature in your forks shoots up to 100 C you won’t even know it and your seals will leak with all the liquid here’s what to do to avoid it
Most forks oil manufacturers will list the metric CST, the viscosity of the oil at — temperatures and for mountain bikes typically if you see the — number at 100 (centi-stroke at 100 C) but you will be fine even if it is 60 CST as well so this is a very simple metric that you should remember as far as the viscosity goes there is no standard like if your manufacturer says that you should use 5w oil in your forks that 5w is not equal to 5 weight it can be higher than that
So this is something that can get very confusing but as a general rule of thumb 15w or higher is OKAY for any kind of cycle and motorcycle including mountain bikes keep in mind that when we are talking about the alternatives there can be some differences in performance and that’s not on my level as well even if you take an
advice from an expert in oils would say the same thing so if you want perfection then maybe consider using something that is recommended but usually, all of the alternatives are just fine
it’s just a disclaimer for people who strive for perfection
Here’s a short list of substitutes that are much cheaper than your recommended (mountain bike, BMX cycles, or any kind of cycling) forks oils
- Motor oils
- Motorcycles fork oil
- WPL 20wt
- Fox gold 20wt
- Lucas motorcycle fork oil
- pro-honda suspension oil
- Castrol oil 10wt
Nearly anything can be used as the fork oil alternative if you know what you are actually putting in them as I have mentioned the above steps for conformation is more than enough to check if the oil will work or not you can buy or use any of these that I listed or if you have a better idea as well
I have already put a baseline on the “usual standard” as there is no industry standard what so ever but if you get confused about things and you are worried you may mess up of course then the recommended stuff is for you for others as long as you understand and the baseline “everything works”
While we are on the subject some forks oils are used in bikes’ hydraulic disc brakes and I have already written an article on it as well that and this case is totally different and you shouldn’t use any brake oil for the forks, fork oil can be used in brakes but it’s not possible otherwise and I have explained that in detail in the hydraulic brake oil substitutes article so keep this in mind as well moving on
Things to use and not to use on Forks legs/stanchion
As far as it goes forks stanchion lubrication there are many options available in that regard as well when they get mud or dirt on them there are many different things you can use for that as well
normally people put vaseline and grease (all types of grease!) on stanchions which do more bad to them than any good grease will stick on the stanchions/legs and will attract more dirt and debris than it would have otherwise with no grease or vaseline and in the case of vaseline it will destroy certain types of rubber seals
anyways even if you apply grease non-the-less it can penetrate through the seals and keep sticking on the walls that will not bring a very good outcome
Similarly, WD40 can not be used as a lubricant on forks its a cleaning agent and should be used as the one you can use it to clean the fork legs of accessive oils or for dirt and other things but make sure it doesn’t seep into the seals because it will degrade the oil and the seals of the forks
Some of the dedicated products for the job are Silicon Shine and Slickoleum and other than these you can use any silicone-based product for it because they are used for low movement high heat applications, best for forks and fork seals but always make sure that you dont buy thicker stuff because that can cause some problems as well.
conclusion :
All the recommendations that I made are based on simple terms or standards that I have described if you use any product that you think falls into that criteria you can use them as a substitute there can be better and worse products out there i just make sure that you have a few recommendations and most of all you have the knowledge to make the decision of deeming those products as useful to you or not.