I'm thinking of servicing my Pikes soon so was browsing for information and found this guide on the Enduro Seals website. In step 31 they recommend using fully synthetic engine oil in the lowers, instead of the 15W fluid that Rock Shox recommend.
Has anyone tried this? If its just there for lubrication then surely engine oil will work better than fork fluid?

NO NO NO NO NO

If you get what I mean

I changed the oil of my Rev's in lowers and I used Fox Float fluid, result the forks hardly moved as the oil was too thick 😳 I strippped the lowers again and replaced the Fox Fluid with 15w fork oil lurvly smooth action as it should of been 🙄

I used fully synthetic motor oil in my old manitou lowers as reccomended in the manitou workshop manual!

Engine oil is pretty thick at room temperature so I wouldn't expect it to do a great job of lubricating a fork.

The thing to remember is to use the right weight oil. I get fork oil from motorcycle shops it's cheap. Most of the shock service centres mix there own. So there is obviously some movement in terms of oil weight but you wouldn't want to put a thick viscosity oil in. At the Motor bike shop they sell 5 wt, 10wt and 15wt. i'm thinking of using a mix of these myself to tune my fork although I need to do some more research.

i followed that guide and serviced my pikes a few times using engine oil and it seemed to work fine

the theory is that suspension oil is meant for providing consistent damping; engine oil is for providing lubrication.

it's meant to work very well but I can't say I've noticed a difference. (i used tftuned lowers mix previously with equal success – ie very little stiction)

Hypoy 90! That's the stuff! 😀

Considering there's next to bugger all going in there you'd get away with nearly anything oil based.

Olive Oil wouldn't do any harm, if you change it often enuff

A synthetic or semi synthetic 10/40 or 15 / 50 at room temperature will have a similar viscosity to 10 wt fork oil or 15 wt fork oil

Considering there's next to bugger all going in there you'd get away with nearly anything oil based.

Olive Oil wouldn't do any harm, if you change it often enuff

ill informed cack if I may say so.

The oil in the lowers is only there to keep the legs lubed so I doubt it's as critical as the oil that goes into the damper etc.

Thanks guys. As I said (OK, maybe implied) in the OP I understand the concept, just wondered if anyone had tried it and thought it was worth doing.

The oil i used was Shell Helix Ultra fully synthetic 5W-40 – not that I specifically chose that – it's just whatever was lying around

I'm thinking of servicing my Pikes soon so was browsing for information and found this guide on the Enduro Seals website. In step 31 they recommend using fully synthetic engine oil in the lowers, instead of the 15W fluid that Rock Shox recommend.
Has anyone tried this?

Yep, i used it in some domains i had last year, it was one of the guys at tft that recommended me to do it as i'd just ordered some new forks off them (month or so wait) and mine were leaking oil and i wasn't going to buy the expensive fork oil for it to just keep leaking out.

They worked fine btw, just as plush as before.

the theory is that suspension oil is meant for providing consistent damping; engine oil is for providing lubrication.

Think your getting slighty mixed up, the oil in the lowers is for lubrication only (and theres only a small amount in each leg) the damping oil is separate.

🙂

Have you seen the price of Fully Synthetic engine oil… go to a motorbike shop, buy fork oil and spend the the £15 you've just saved on something nice for the wife.

A synthetic or semi synthetic 10/40 or 15 / 50 at room temperature will have a similar viscosity to 10 wt fork oil or 15 wt fork oil

Think you've got things the wrong way round there TJ, the first weight is the viscosity at operating temperature iirc.

Have you seen the price of Fully Synthetic engine oil

For me it was just some i had lying around in the garage, there's only a tiny amount in each leg, it was convenient at the time.

No way would i go out and specifically buy 4 litres of fully synthetic to put a couple of table spoons full in some forks, that would be a little bit daft…

🙂

jackal
Think your getting slighty mixed up, the oil in the lowers is for lubrication only (and theres only a small amount in each leg) the damping oil is separate.

I know, but he was talking about the semi-bath wasn't he?
Point is that normally with RockShox you use suspension (damping) oil in the semi-bath, but engine oil supposedly works better.

Oops Vinnyeh, first number cold, second hot (ie:90degc), you dont want you oil to behave as a thinner oil when hot and act as thick when cold now do you you?

Oops Vinnyeh, first number cold, second hot (ie:90degc), you dont want you oil to behave as a thinner oil when hot and act as thick when cold now do you you?

oops indeed. 😳