GS850 stator thickness question

[Steve]

In the process of getting the bikes ready for our "little ride", I have planned on starting with brand-new stators in all three bikes. I have seen several recommendations for brands, which includes a WIDE range in prices.

I decided to bite the bullet and got three Electrosport stators. One for the 1000, two for the 850s. The 1000 stator went in and is working just fine. I opened up the package to replace the stator on my bike today and was rather surprised to find that the Electrosport stator was a bit thinner than what was in my bike. I am reasonably certain that what is in my bike is not stock, as all three wires are WHITE, but I have no idea what it is.

The central core, where the three holding bolts fit, is about 19mm thick on my current stator, but only 14.5mm on the Electrosport. Out on the outer edge of the windings, the current one is 27.3mm, the ES is 22.8mm.

The mounting holes are aligned properly, but the bolts are too long to hold the ES stator tightly to the cover.

It will probably work, but I'm sure the output will be limited a bit. With our "little ride", I don't think I want to accept a limited output.

I have sent a message to Electrosport, but I don't expect to hear anything from them until tomorrow.

Has anybody else had any issues with mounting an Electrosport stator?
Is there another brand that has an execllent reputation?
Yes, I already have SH775 R/Rs fitted to all three bikes.

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[posplayr]

In the process of getting the bikes ready for our "little ride", I have planned on starting with brand-new stators in all three bikes. I have seen several recommendations for brands, which includes a WIDE range in prices.

I decided to bite the bullet and got three Electrosport stators. One for the 1000, two for the 850s. The 1000 stator went in and is working just fine. I opened up the package to replace the stator on my bike today and was rather surprised to find that the Electrosport stator was a bit thinner than what was in my bike. I am reasonably certain that what is in my bike is not stock, as all three wires are WHITE, but I have no idea what it is.

The central core, where the three holding bolts fit, is about 19mm thick on my current stator, but only 14.5mm on the Electrosport. Out on the outer edge of the windings, the current one is 27.3mm, the ES is 22.8mm.

The mounting holes are aligned properly, but the bolts are too long to hold the ES stator tightly to the cover.

It will probably work, but I'm sure the output will be limited a bit. With our "little ride", I don't think I want to accept a limited output.

I have sent a message to Electrosport, but I don't expect to hear anything from them until tomorrow.

Has anybody else had any issues with mounting an Electrosport stator?
Is there another brand that has an execllent reputation?
Yes, I already have SH775 R/Rs fitted to all three bikes.

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Steve, I have mentioned this point many times in the past, but it seems to bear repeating. The maximum power output of the stator actually has nothing to do with the stator. It has to do with the amp rating of the rotor. (Huh??) The power output of the stator goes up in proportion to the square of RPM as long as your rotor magnetics does not saturate. If the stator did not saturate you would very quickly finding an overwhelming amount of power coming out because of the RPM^2 dependency. (this is why voltage rises so quickly from idle but stops later at 3K and above)

Basically, the conversion from mechanical-to-electrical power tapers off due to magnetic saturation of the rotor magnetics.

https://en.wikipedia.org/wiki/Saturation_(magnetic)

This phenomenon is a predominant factor in all motors and generators.

The only question in my mind is do you believe Electrosport is increasing power out by 20%? If they are it is at some lower RPM below to the total saturation effects.

The only way to measure the effect is to put a clamp on current meter onto the stator lines and measure how current increases with RPM for two different stators. Once they saturate (3-3.5 RPM) they will be the same. This saturation is also what the Shut R/R even have a hope in He!! fo working.

[Steve]

Jim, I don't know that Electrosport is claiming any increase in output, and I can't even check it until it gets mounted. To mount it, I will have to either install spacers or shorter bolts. And, it's the Electrosport stator that is the smaller one.

And, ... even after mounting it, I will have to finish putting the engine back together. I have my new rings mounted to the brand-spanking-new OEM pistons and the pistons back on the crank, but have yet to drop the cylinders back onto the crankcase.

The stator that was in there may be going back in, but I was hoping to start the "little ride" with known-good items for all three bikes, especially the items that can sideline a ride. New items are stator, R/R, clutch cable. Ignitors are staying, but we have replacements for each. Of course, we are starting with new tires, brakes, oil and filters, too.

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[posplayr]

Jim, I don't know that Electrosport is claiming any increase in output, and I can't even check it until it gets mounted. To mount it, I will have to either install spacers or shorter bolts. And, it's the Electrosport stator that is the smaller one.

And, ... even after mounting it, I will have to finish putting the engine back together. I have my new rings mounted to the brand-spanking-new OEM pistons and the pistons back on the crank, but have yet to drop the cylinders back onto the crankcase.

The stator that was in there may be going back in, but I was hoping to start the "little ride" with known-good items for all three bikes, especially the items that can sideline a ride. New items are stator, R/R, clutch cable. Ignitors are staying, but we have replacements for each. Of course, we are starting with new tires, brakes, oil and filters, too.

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While you have them out can you post pictures and which is which? What I think is most important is the amount of epoxy they have on them. That is the biggest determinant on how long it will last all other things being equal.

[Steve]

Will get some pics and post them in a bit.

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[Steve]

OK, picture time.

This is the stator that has been in my bike for some time. Apparently working well, but I want to start with a fresh one.
Not sure of the manufacturer, but I have purchased a Caltric unit or three in the past, this might be one of them.



A close-up of the epoxy on the windings:


This is the brand-new Electrosport:


and a close-up of its windings:


Finally, the difference in thickness:


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[posplayr]

The winding on the Calric actually looks better as it doesn't have those long bridges skipping3-4 poles as on the Electrosport.

The epoxy looks pretty heavy on both except on the side by side photo looking between the poles. As far as thickness it is not obvious to me which would be better. Voltage gain has to do with the number of windings are there more or less? It depends on the thickness of the metal portion of the pole and the magnetic resistance of the metal/size/shape.

[tom203]

I'd stick with your existing stator....the e/s looks crudely wound and I'm no fan of the hidethecrimescene epoxy dip. Anyway, when I installed my sh-775 back in 2013, I left the previously used 30 yearold stator in place. No issues yet.
On the oem stators that I've collected, there is some variation in thickeness due to # of plate laminations, but nothing like what this e/s version shows.

[Steve]

The epoxy is not to "hide the crime scene". As the magnets in the rotor pass by the windings and the current flow reverses, there IS a bit of movement in the wires. That movement will eventually wear through the insulation, shorting the windings. The epoxy prevents that movement.

As far as "crime scene" evidence, you can usually see the windings through the epoxy. If they are nicely-wound, you will see nice, smooth windings, much like the Caltric (?) stator that was in my bike. I agree that the Electrosport unit does not look quite so nice, but one stator has the bridges from one pole to the next on the front, the other has it on the rear. I will have to turn one of them over to get a better comparison.

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[posplayr]

The epoxy is not to "hide the crime scene". As the magnets in the rotor pass by the windings and the current flow reverses, there IS a bit of movement in the wires. That movement will eventually wear through the insulation, shorting the windings. The epoxy prevents that movement.

As far as "crime scene" evidence, you can usually see the windings through the epoxy. If they are nicely-wound, you will see nice, smooth windings, much like the Caltric (?) stator that was in my bike. I agree that the Electrosport unit does not look quite so nice, but one stator has the bridges from one pole to the next on the front, the other has it on the rear. I will have to turn one of them over to get a better comparison.

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Steve, I was glad you answered this. I would, however, clarify your statement above(hopefully not over complicate it).

There is first a force on the wire associated with the electromotive force (i.e. when a wire moves through a magnetic field there is a current produced which is opposed by a force on the wire).

The force may or may not flex the wire relative to the stator. If the windings are epoxied, then the wires are restrained and the epoxy immobilizes the windings by taking the force. If there is no epoxy, (and nothing to back up the windings), then the force can eventually start to flex the wire eventually work hardening and breaking the wire.

[tom203]

A good electrical varnish will wick in the wound stator nicely,and prevent windings from moving . The goop is handy if you drop the stator during installation. Years back, I remember reading about a poor hinda cv500 guy who experienced failures on two e/s stators - very pretty and well gooped ,but poorly wound ,. shorting out quickly

[posplayr]

A good electrical varnish will wick in the wound stator nicely,and prevent windings from moving . The goop is handy if you drop the stator during installation. Years back, I remember reading about a poor hinda cv500 guy who experienced failures on two e/s stators - very pretty and well gooped ,but poorly wound ,. shorting out quickly

I should hope the point is clear, the windings should not move under the electromotive forces. A "proper" winding uses the poles to support the wire (but this can only backstop the wire and not resist any pulling force). An epoxy or electrical varnish provides adhesion to oppose pulling forces.

An area of special attention is where the stator wires exit the windings; they are most susceptible to mechanical work hardening.

[tom203]

"An area of special attention is where the stator wires exit the windings; they are most susceptible"

yes, and very susceptible to mechanical damage from the clamp if one gets careless.

[Steve]

OK, I have received a reply from a sales manager at Electrosport.

The stator can work with your machine. The change to the stator core is intentional, the core needed to be smaller to offset a more powerful winding. You could get shorter bolts and use the stators you have currently. If you cannot get shorter bolts than the stators would need to be returned.

I guess I will have to send a reply asking what was done to achieve a "more powerful winding".

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[posplayr]

OK, I have received a reply from a sales manager at Electrosport.



I guess I will have to send a reply asking what was done to achieve a "more powerful winding".



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As I mentioned it is a non-obvious trade-off between number or windings, wire cross-sectional area and magnetic flux that the steel poles can support. If they say more power, it can only exist at lower RPM.
Only by working the complex tradeoffs of the design can you find an optimum that produces more power.

I would be interested in his answer, and especially a quantitative comparison (e.g. ES vs. OEM) is he could provide it.