Cycle Electric regulators
Cycle Electric regulators
After the recent charging threads, and since I'm currently (get it? Currently?...) replacing much of my electrical / starting systems at 50K, I have a question for those who KNOW stuff about regulators.
I have the stock Harley regulator on my '14 FLHTK. The Cycle Electric website says "To control voltage on Harley-Davidson alternators other rectifier regulators dump current to ground. This causes maximum stator current and temperature at all times. Cycle Electric rectifying regulators block current to control voltage. This reduces stator current resulting in lower temperature and less drag on the motor which means more efficient operation.". Does anyone know if the stock Harley voltage regulators dump excess energy to ground, or if they behave much like the Cycle Electric ones? Reason for asking is for the $250 I'll swap it if it might improve the lifespan of the rest of the system, but if it's not really an upgrade, I'll wait.
Some bitter pos(t)er is going to say "call and ask them". Yes, I can do that if I need to, but this is a discussion forum, so I came here to discuss it first.
I have the stock Harley regulator on my '14 FLHTK. The Cycle Electric website says "To control voltage on Harley-Davidson alternators other rectifier regulators dump current to ground. This causes maximum stator current and temperature at all times. Cycle Electric rectifying regulators block current to control voltage. This reduces stator current resulting in lower temperature and less drag on the motor which means more efficient operation.". Does anyone know if the stock Harley voltage regulators dump excess energy to ground, or if they behave much like the Cycle Electric ones? Reason for asking is for the $250 I'll swap it if it might improve the lifespan of the rest of the system, but if it's not really an upgrade, I'll wait.
Some bitter pos(t)er is going to say "call and ask them". Yes, I can do that if I need to, but this is a discussion forum, so I came here to discuss it first.
Road Captain
Joined: Mar 2020
Posts: 650
Likes: 351
From: Sierra foothills
May want to ask this over in electrical forum
I think cycle electric is referring to earlier harley charging system voltage regulators that are/were single phase vs their single phase regulators. Your system is 3 phase. Don't know if cycle electric 3 phase regulators are functionally different from HD. 3 phase is inherently more efficient by factor of square root of 3 vs single phase.
If it ain't broke, don't fix it
I think cycle electric is referring to earlier harley charging system voltage regulators that are/were single phase vs their single phase regulators. Your system is 3 phase. Don't know if cycle electric 3 phase regulators are functionally different from HD. 3 phase is inherently more efficient by factor of square root of 3 vs single phase.
If it ain't broke, don't fix it
Last edited by tdrglide; Oct 25, 2023 at 04:25 AM.
Road Master
Joined: Sep 2021
Posts: 759
Likes: 936
From: Under the affluence of incahol.
I fitted a Cycle Electric reg/rec to my Evo RK after the stock one died.
My understanding from when I looked into it at the time (a few years ago now) was that stock type reg/rec units basically run the alternator at full output all the time and all the excess voltage runs to ground through a Zener diode that converts the excess voltage to heat, hence the cooling fins on the unit. The CE unit controls alternator output so that it only produces what the bike's system needs at that particular time.
But exactly how the CE unit does that controlling I do not know, as there is no set of rotor windings to control in order to vary the output, eg like there is on a car alternator. It may be that if the stator is putting out three phases, the regulator switches the second and third phase coils in and out as needed.
But then again, if your current (geddit?) regulator is working fine, I would leave it well alone. Clean the plug terminals and pack with silicone grease and carry on. They don't seem to be a real common cause of problems. I have seen them with an extra ground wire attached with a PK screw into one of the cooling fins on the reg/rec unit running to a good ground on the frame or wiring loom, just for good measure. Seems a lot of ex-police bikes have that little extra wire.
My understanding from when I looked into it at the time (a few years ago now) was that stock type reg/rec units basically run the alternator at full output all the time and all the excess voltage runs to ground through a Zener diode that converts the excess voltage to heat, hence the cooling fins on the unit. The CE unit controls alternator output so that it only produces what the bike's system needs at that particular time.
But exactly how the CE unit does that controlling I do not know, as there is no set of rotor windings to control in order to vary the output, eg like there is on a car alternator. It may be that if the stator is putting out three phases, the regulator switches the second and third phase coils in and out as needed.
But then again, if your current (geddit?) regulator is working fine, I would leave it well alone. Clean the plug terminals and pack with silicone grease and carry on. They don't seem to be a real common cause of problems. I have seen them with an extra ground wire attached with a PK screw into one of the cooling fins on the reg/rec unit running to a good ground on the frame or wiring loom, just for good measure. Seems a lot of ex-police bikes have that little extra wire.
Last edited by PeterB; Oct 25, 2023 at 05:22 AM.
Road Warrior
Joined: Dec 2019
Posts: 1,783
Likes: 938
From: Ohio
After the recent charging threads, and since I'm currently (get it? Currently?...) replacing much of my electrical / starting systems at 50K, I have a question for those who KNOW stuff about regulators.
I have the stock Harley regulator on my '14 FLHTK. The Cycle Electric website says "To control voltage on Harley-Davidson alternators other rectifier regulators dump current to ground. This causes maximum stator current and temperature at all times. Cycle Electric rectifying regulators block current to control voltage. This reduces stator current resulting in lower temperature and less drag on the motor which means more efficient operation.". Does anyone know if the stock Harley voltage regulators dump excess energy to ground, or if they behave much like the Cycle Electric ones? Reason for asking is for the $250 I'll swap it if it might improve the lifespan of the rest of the system, but if it's not really an upgrade, I'll wait.
Some bitter pos(t)er is going to say "call and ask them". Yes, I can do that if I need to, but this is a discussion forum, so I came here to discuss it first.
I have the stock Harley regulator on my '14 FLHTK. The Cycle Electric website says "To control voltage on Harley-Davidson alternators other rectifier regulators dump current to ground. This causes maximum stator current and temperature at all times. Cycle Electric rectifying regulators block current to control voltage. This reduces stator current resulting in lower temperature and less drag on the motor which means more efficient operation.". Does anyone know if the stock Harley voltage regulators dump excess energy to ground, or if they behave much like the Cycle Electric ones? Reason for asking is for the $250 I'll swap it if it might improve the lifespan of the rest of the system, but if it's not really an upgrade, I'll wait.
Some bitter pos(t)er is going to say "call and ask them". Yes, I can do that if I need to, but this is a discussion forum, so I came here to discuss it first.
2- No aftermarket electrical replacement parts work as well as OE.
3- When the stock regulator went out on my 2012 FLHTK this spring I put a new OE reg on and never had an issue.
4- Dont try to reinvent the wheel.
HDF Community Team
Joined: Nov 2012
Posts: 6,186
Likes: 2,412
From: USA
The geek engineer says not true about simply dumping to ground. That would be a runaway short, and things would quickly overheat and burn out.
But, as is often the case, theres a grain of truth to such claims. Going way back to generators and mechanical regulators, ground was used to move the contacts that regulate the voltage. Current flow was simply a product of the load, as per basically ohms law.
Modern electronic regulators still use ground for reference in establishing the charging voltage.
If either system fails, it can potentially create a short to ground, creating a runaway that burns out things.
Far more common was a wiring failure. Particularly at the stator winding leads where the exit the motor. This is hot from the running engine, often oily, and the insulation often breaks down, shorting a stator winding to ground, and starting a small fire in the insulation. Goldwings were notorious for this for example.
But, as is often the case, theres a grain of truth to such claims. Going way back to generators and mechanical regulators, ground was used to move the contacts that regulate the voltage. Current flow was simply a product of the load, as per basically ohms law.
Modern electronic regulators still use ground for reference in establishing the charging voltage.
If either system fails, it can potentially create a short to ground, creating a runaway that burns out things.
Far more common was a wiring failure. Particularly at the stator winding leads where the exit the motor. This is hot from the running engine, often oily, and the insulation often breaks down, shorting a stator winding to ground, and starting a small fire in the insulation. Goldwings were notorious for this for example.
Seasoned HDF Member
Joined: Mar 2021
Posts: 17,923
Likes: 3,561
From: backwoods
Most people recommend CE. In the past volt regs were a huge problem for Harley. People would carry spares, I did for awhile. It seems to have gotten better.
One bike I removed volt reg at 55k for another reason, and the bottom was warped. Probably going to fail. If you have the bike apart and the money, 50k is not the worse time to replace it in my opinion. You got your money out of it.
Not saying I would replace tomorrow, but if I had it off for some reason I would think about it.
Many people like to keep parts until it leaves them stranded on side of the ride. I try not to do that.
One bike I removed volt reg at 55k for another reason, and the bottom was warped. Probably going to fail. If you have the bike apart and the money, 50k is not the worse time to replace it in my opinion. You got your money out of it.
Not saying I would replace tomorrow, but if I had it off for some reason I would think about it.
Many people like to keep parts until it leaves them stranded on side of the ride. I try not to do that.
Seasoned HDF Member
Joined: Mar 2021
Posts: 17,923
Likes: 3,561
From: backwoods
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Seasoned HDF Member
Joined: Dec 2005
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From: poway
Technically, I don't think they dump the current to ground. I think they use a Daic or SCR and short the winding out..
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Road Warrior
Joined: May 2007
Posts: 1,428
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From: Arkansastan
Shorting excess to ground was very common in bikes. Not too sure on the Harley, but on most Japanese bikes, you could tell which were short-to-ground regulators and which were open-line type, which simply interrupted the output of the stator by the amount of heat sinking on the regulator. The short-to-ground had a large area of cooling fins, the open-lines didn’t. A common fix for older Suzuki GS series which ate stators on a regular basis because of the full output all the time was to use the open-line type regulator from a Honda gold wing of the era, which used the open-line type.
Seasoned HDF Member
Joined: Jun 2014
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From: pacific northwest
Shorting excess to ground was very common in bikes. Not too sure on the Harley, but on most Japanese bikes, you could tell which were short-to-ground regulators and which were open-line type, which simply interrupted the output of the stator by the amount of heat sinking on the regulator. The short-to-ground had a large area of cooling fins, the open-lines didn’t. A common fix for older Suzuki GS series which ate stators on a regular basis because of the full output all the time was to use the open-line type regulator from a Honda gold wing of the era, which used the open-line type.
The HD ones must be better as have 65k on the FXDL, 46K on the Limited and they still charge ok.