FAQ  r1.6

Nozzles

1.  Is there a "best" placement for a nozzle?

Yes, definitely.

Delivering the oil to the chain is not just a question of pointing a tube somewhere near the chain, and firing the pump!

Correct placement and alignment makes a real difference to performance.

Current short-arm nozzle types:

· Pointing onto the sprocket at around the 8 o'clock position on the sprocket (or 4 o'clock on bikes with the chain on the right hand side).

· The nozzle tips must be lightly touching the sprocket, so that the oil is smeared onto the sprocket when the pump fires.

· The oil gets into the chain as the centrifugal force flings it into the chain rollers

· The current short-arm nozzles are easy to align and locate perfectly.

Earlier, long-arm nozzle types

· At, or a bit before the point at which the lower chain run meets the rear sprocket - so from 6 o'clock to 7 o'clock (or for bikes with the chain on the right hand, side from 6 o'clock to 5 o'clock)

· Not touching the chain, but 2-3mm above it

· Pointing onto the sprocket so that the oil slides down onto the chain's inner plates. The nozzle tips should touch the sprocket lightly

Why is this the "best" place?

· The objective is not to lose oil to air turbulence before it gets onto the sprocket, and from there onto the chain. This is why the nozzle tips need to touch the sprocket - oil comes out from the ends of the tubes with a smearing action.

· Trying to "drop" oil onto the top of the chain will only work at a standstill - as soon as there is turbulence, some of the oil will be blown away without touching the chain.

· Lubing the chain on the top of the lower run before it goes round the sprocket forces the oil onto the chain due to centrifugal force

· For the long-arm versions, the advantage of placing the tips as close to 6 o'clock as possible is that the chain does not move vertically once it has engaged on the sprocket - and so cannot damage the nozzle arms.

· This is not an issue with the short-arm versions, which never get anywhere near the chain - indeed the short-arm types have the additional advantage that they have a broader area to target, especially useful for sprockets with the bolts widely spaced and close to the chain (eg. single-sided swingarm types, some Aprilias)

· If the nozzle is located ahead of the sprocket in free air, then

· It has to be placed with enough clearance to the chain so that it does not get damaged by the chain

· This makes the whole system less efficient and results in more fling-off.

· In short - it's really not advisable, and there should never be any need as there is always a nozzle type available that deposits oil on the sprocket face.

2.  Can I place the nozzle on the front sprocket?

In principle yes, but there are some practical disadvantages:

· It's inconvenient to get access to the nozzle

· for maintenance

· or even just to check it

· or see the oil coming out when you prime the lines

· To check the nozzle's condition you may have to take the cover off, and on some bikes that can mean removing the fairing...

· Bear in mind the nozzle must be placed either

· above the lower run of the chain - the top run is not viable because the oil will fling off straight away as it goes round the sprocket.

· or depositing oil on the rear face of the front sprocket, and from there it gets centrifuged into the chain.

However, for bikes used off-road, there can be very good reasons to fit the nozzle(s) at the front sprocket. The setup may be a bit less efficient, but:

· A nozzle setup on the rear sprocket in off-road use is vulnerable to damage from all sorts of sources, whilst up front the nozzle is better protected

· If you ride in deep mud, or through brush, then in fact the front sprocket may be the only option

3.  Why is a twin nozzle better than a single nozzle?

This is a BIG issue!

To explain this you need to bear in mind that there are basically 3 aspects to lubing a chain:

1. The most important point is to get the oil into the bushing and roller. This is the area where the wear occurs, resulting in chain "stretch" - the play between the inside of the rollers and the bushing increases. Lack of lubrication here is damaging to the chain - and is the main reason why spray-on lubricants can't match the performance of continuous lubrication from a chain-oiler.

2. The o-rings also need lubricating to reduce heat build-up through friction, and also to prevent degradation from UV radiation and chemical in road grit which are aggressive to NBR rubber. To test the amount of resistance o-rings can generate on their own, here's an easy and safe experiment:

· Spin the wheel by hand when the chain is dry and gauge the resistance. This can often be so strong that it needs a lot of effort to do.

· Then take a can of WD40 and quickly spray the chain o-rings on each side (not the rollers - we're isolating the effect of friction in the orings here). The wheel will instantly turn more freely - due almost entirely to the reduced friction between the o-rings and the plates. (Don't worry, WD40 does no damage to o-ring seals!) 

3. Corrosion protection for the side-plates. In reality more of a cosmetic issue, but still a point - a rusty chain is not a pretty sight!

Gravity feed chain-oilers have been using a single nozzle for years, so what's the problem?

· A single nozzle setup only lubes one side of the chain. The really important job of getting oil into the bushing/roller area is achieved just as effectively by single as by twin nozzles - the oil is sucked in by capillary action.

· The pair of outer plates and o-rings (the ones furthest from the wheel) will also be lubed because you are depositing the oil onto the plate next to the sprocket. However, the plates on the chain run next to the wheel may not be receiving enough oil to provide any corrosion protection,  and much more serious - not even lubricate the o-ring.

· The only way a single nozzle setup can get oil to the plates and o-rings next to the wheel is by being set rich - then the oil gets to this area by means of aerodynamic turbulence - the swirling air literally does the job of coating the chain with oil. Fling-off is being left to do the job!

· On a gravity feed system the oil deposition is varying all the time with temperature and speed changes - at high temperatures more oil is flowing, and at low speeds one and the same setting will be too rich

· This rich running is all part of life with a gravity feed system, but it does mean that on average the inside links and o-ring should be well lubed - but the price of this is a lot of fling-off

· The PRO-OILER's delivery does not vary in this way, so a single nozzle on a PRO-OILER needs to be set rich enough so that turbulence gets the oil to the inner links and o-rings. This somewhat defeats the advantages of the PRO-OILER's efficient delivery!

· The double disadvantage here is that if you run a PRO-OILER with a single nozzle at low speeds, there won't be enough turbulence to distribute oil to the other side of the chain - this "distribution" will only occur at higher speeds.

· A very simple experiment can demonstrate this: 

· Run the chain fairly dry at low speeds for 50+ kms (so that you can see a clear difference between the condition of the outer and inner plates and o-rings)

· Then go out on the open road at 120km/h or more for 50kms. You will see the chain is more evenly lubed after running at higher speed.

The answer to the whole problem is to use a twin nozzle setup

· Then a lean setting can be used

· The entire chain gets just enough oil to lube and protect it, but with a minimum of fling-off. Turbulence plays a much smaller rôle in getting the oil to where it needs to be - it's only really a factor in coating the outside of the outer links.

Advantages all round, and the reason that PRO-OILER strongly encourages wherever possible the fitting of a twin nozzle setup - and why the twin nozzle is included as part of the system.

4.  Does the nozzle material matter? Can I use a brass or aluminium tube?

Yes, the material does matter.

Metal nozzles may look attractive initially, but they have serious disadvantages in practice

· Thin-gauge brass and aluminium tubing is extremely fragile. The slightest contact can bend, deform, or clamp the nozzle tube shut. And once deformed, because of the poor elasticity, they may be permanently damaged and need replacement. Potential disaster when away on a trip.

· The polyamide tubing used by PRO-OILER has proven ability as nozzle material

· Firm enough to hold its shape and position.

· Flexible enough to survive becoming snagged in the chain (for example, when reversing - long-arm versions)

· Significant wear resistance - the nozzle opening seldom deforms.