Multigrade Fork Oil

[KungFooBob]

Surely some mistake?

https://www.halfords.com/motoring/motor ... 24393.html

[Yorick]

It's only scooters

I bought some decent 2 stroke a while ago in a rush and when I got home I saw it was for scooters. It's not going in the Husky

[KungFooBob]

I've just never seen fork oil with a multigrade rating, its usually 5w, 10w, 15w, etc... never 5w/30!

[Le_Fromage_Grande]

That's an interesting idea, damping that changes with the temperature of the oil

[Mr. Dazzle]

Surely the idea would be the other way around....damping which doesn't change with the temperature of the oil. Fork oil gets hot when it's doing it's job (all the energy that the damping takes out is converted to heat in the oil), so multi grade would make sense.

[KungFooBob]

But isn't the non-W bit the viscosity at 100c?

I wonder how 'hot' the oil in forks gets?

[Yorick]

That's an interesting idea, damping that changes with the temperature of the oil

They work OK as they are. I've never heard a racer complaining that suspension doesn't work at the end of a race.

[Mr. Dazzle]

But isn't the non-W bit the viscosity at 100c?

I wonder how 'hot' the oil in forks gets?

Dunno about bikes tbh...probably not that hot cause there's a lot of oil! Off road would probably be worse just cause the suspension travels alot.

Certainly in F1 damper temperature is a thing they worry about.

Also on road cars when you do 'accelerated wear' testing on a super bumpy test track you have to drive through a 'damper cooling trough' of water every so often.

[JackyJoll]

Surely the idea would be the other way around....damping which doesn't change with the temperature of the oil.

Multigrade should give you damping which changes less, but it does thin out with rising temperature, so damping will change.

[Le_Fromage_Grande]

That's an interesting idea, damping that changes with the temperature of the oil

They work OK as they are. I've never heard a racer complaining that suspension doesn't work at the end of a race.

I didn't say it was a good idea

[Mr. Dazzle]

Surely the idea would be the other way around....damping which doesn't change with the temperature of the oil.

Multigrade should give you damping which changes less, but it does thin out with rising temperature, so damping will change.

Change less than a single grade though....which would make more sense.

[Le_Fromage_Grande]

Surely the idea would be the other way around....damping which doesn't change with the temperature of the oil.

Multigrade should give you damping which changes less, but it does thin out with rising temperature, so damping will change.

Change less than a single grade though....which would make more sense.

Do your forks get hot enough for the temperature of the oil to significantly change?

[JackyJoll]

Do your forks get hot enough for the temperature of the oil to significantly change?

And hot enough for the difference in hot viscosity between multi and mono to noticeably affect the ride.

[Mr. Dazzle]

Multigrade should give you damping which changes less, but it does thin out with rising temperature, so damping will change.

Change less than a single grade though....which would make more sense.

Do your forks get hot enough for the temperature of the oil to significantly change?

Dunno about mine, but presumably someone's do hence the availability of the product.

EDIT: Just thinking about it some more, it would also make a lot more sense in other countries. We perhaps forget that the UK has a pretty narrow temperature range, it's generally somewhere around 5-25°C with not much variation either side, sure it does get cold or hot but typically we're straight down the middle. What about if you live somewhere like Colorado where it can be -20°C in Winter and +30°C in Summer pretty normally?

[Yorick]

That's an interesting idea, damping that changes with the temperature of the oil

They work OK as they are. I've never heard a racer complaining that suspension doesn't work at the end of a race.

I didn't say it was a good idea

The nerdy kid is trying to prove it's needed.

I've been in pit crews right up to BSB level and at the TT. Never heard of any problems. Often seeing lap records on last lap.

Even Motogp set lap records on last lap.

No hay ningún problema

[Mr. Dazzle]

Motorsport - particularly top flight- is a very narrow set of conditions though, everything is right in the zone and nowhere else.

As above, damper fluid temperature is deffo a consideration in F1. I know this from making bits for their damper fluid systems.

[JackyJoll]

They work OK as they are. I've never heard a racer complaining that suspension doesn't work at the end of a race.

A lot of them complain about everything at the end of a race.

[KungFooBob]

BTW, I've been to Halfrauds and bought a bottle today.

The viscosity isn't a worry because the forks on Big Red don't have any internals, the oil is just lube for the sliders.... and the branded stuff was double the price.

[Le_Fromage_Grande]

I think it's a mis labelled product, it's standard fork oil.
Though forks used to come with ATF in them, I wonder if it's a multigrade ATF.

[KungFooBob]

it's a mis labelled product

Was my thinking too.