Motor oil in the shock?!!?

[Jeffro426]

After trying to teach my hard headed friend how to turn wrenches on a bike, he calles me over to his house last night to check out his latest doing...he "serviced" his forks he tells me.

Right on...not to hard was it...

Nope, it was pretty easy.

Cool, what kinda fork fluid did you use?

Fork fluid?

Yeah, you know...the stuff you usually buy in bottles that says fork oil/fluid or the likes.

Uhh, the book said 5W so i figured 5W-20 motor oil would work fine.

:ohmy: :bang: :bang:
So, after i just stood there and shook my head and asked myself why i even try it got me wondering...will it work, or should he drain the crap and put the correct stuff in??

 

[terry hay]

It should work ok without a major difference. You should perhaps suggest that he changes the oil a little earlier than perhaps you would normal fork oil. A lot of engine oils will have similar additives to that of fork oil. The main concern would be if the particular oil he used has seal swelling agents in the blend. If it has he may soon experience unwanted drag making his forks feel harsh. Suspension fluids generally have high quality base oils with a range of additives from friction modifiers to temperature stabilizing mediums. He may find that the engine oil also contaminates a little easier necessetating the earlier change.
Terry

 

[Vic]

Some manuals specify motor oil as an option. The main difference, from a performance standpoint, is that fork oils have anti-foaming additives.
There are also viscosity issues, as the "w" in 5w stands for "weight" ,while in the case of 5w-20 it stands for "winter".

 

[sunnyboy]

high preformance oils have anti-foaming additives in them as well--the 5-20 is thicker than a straight 5 this will make the forks stiffer and rebound slower,you can play with the clickers and see if you can get it to work you may like it better and you may not-i would change it but that is up to you guys.this is what r&d is all about

 

[matt-itude]

hey guys on the topic of motor oil viscosities the two numbers such as 10w30 are actually two seperate viscosities. in the 10w30 example 10w is messured at a predetermined(i dont remember the exact temperatures)temp. of the oil then the 30 part at a different (higher temp)of the same sample oil. What im trying to say is the modifing additives in that oil cause it to flow easier at a lower temp and not thin out as much (compared to a straight wheight such as 10w) with temp increase. so at a lower temp 10w30 flows at the same rate as 10w and at the higher temp the same as 30w. I know straight 30w does pour thicker out of a bottle at room temp than 10w30 but that is because 75 deg. is cold in engine temp. terms hence 10w and if the oil manufacturers are correct with the engine good and warm (200+) 10w30 and 30w should come out at the same rate (not the 10w30 any faster than the 30w) also note worthy in the topic of durability is in engines and i would assume(you know what they say) the same in suspension that the multi viscosity oils (10w30) are not as stable\durable as the single viscosities because in a said amount of oil a multiviscosity is a higher % additive and less oil. Alot of the fancy things they do with anti foams and viscosity enhancers cause you to purchase more % additive and less % oil in the said amount and usually the additives are the expensive part. In conclusion as said some motor oil additives may not be suitable for suspension components such as seals etc. and who knows how the multiviscositi is going to affect suspension action in its normal temperatures. Just my 2c

 

[Jman271]

:ride: As long as he changes it every 3k miles, he should be OK!

 

[Vic]

Ha! :)

 

[JasonWho]

LOL! Unless it was synthetic! :-)

 

[KiwiBird]

Now that it's got motor oil in there he can take them to Jiffy Lube and get them to change it.

 

[matt-itude]

I know we are (at least most of us) on a budget. Now if the service manual says it can be used great. However a tranny rebuild on a bike can be as expensive as on a car, etc. I know were talking suspension not trannys but when I was asking similar questions about substituting various oils at the bike shop my bro. works at they all looked at me and said "would you run motorcycle oil in your car?" they all know im a car mechanic and when i thought about it heck even the good stuff for my bike is cheeper than the average stuff for my car. just a thought!

 

[matt-itude]

you know I was just rereading the thread and wanted to ask you guys since bikes are pretty new to me (especially the suspension repair and maintenance) was jason joking or can you use a synthetic oil and stretch you service intervals some?

 

[JasonWho]

Well....a higher quality oil will break down less than a cheap oil, so in a sense my joke was correct.

What are you calling average oil for a car? Most motorcycle oil quarts or liters are around $5. Average car oil is $1.75 or so.

As far as what the service manaul says, I do not agree with EVERY thing my service manuals say.

 

[Vic]

It would be fine to use motorcycle oil in a car. As far as I know, the major difference in m/c vs. car oil is the higher level of zinc in the m/c oil. Zinc causes problems for catalytic convertors. I believe that Mobil 1 contains no zinc, but is more than adequate for m/c engines and probably overkill for the average auto.

Were we talking about suspension? :)

 

[matt-itude]

yeah this has turned more oil in general talk. when i said cheeper per oil change i meant my car needs a filter for 2 to 5$ and 4 to 5 quarts of oil my bike needs 1 quart that is what i was saying and like ive said im a car and heavy equipment guy so Im counting on your info to be precise. thanks all!