Let's talk about other ways to upgrade the stock alternator - "pancake" and hidden options

[Syscrush]

The other alternator discussion about mechanical fitment of a Denso alternator included this off-topic recent photo from Jean Luc Millet:



As it turns out, he later explained that it's from a "2020 Honda" - I assume something like a CBR1000RR. The rotor on those is the flywheel, the stator is pretty narrow. This is looking like a very cool way to go, though you'd need to find a place for an external voltage regulator/rectifier. Here's a video that shows a similar assembly:



FWIW, Suzuki went from an external alternator on the air/oil cooled Bandit/Katana motors to a setup like this one when they upgraded to liquid cooling and EFI in 2007.

So you'd need that custom cover to house and mount the stator, and a custom rotor in place of the OEM clutch assembly. Since the CBX doesn't rely on the rotor to act as a flywheel, it would make sense for it to be as light as possible. Seems well within the abilities of multiple people on this board. Furthermore, it looks to me like it would be possible to retain something very close to OEM looks. Once a conversion like this one was done, it would not be difficult to add a decorative cover that is a very close match to the OEM alternator. Alternatively, a single custom cover that includes any necessary internal mounting features for the electrical components while appearing stock from the outside could be fabricated.

This is something that I'd really like to do in principle, because I want greater electrical output than the OEM setup, but would be happy if I could retain the OEM looks. I understand the basics of how alternators work, whether the type where the rotor field is regulated via brushes, or the permanent magnet style with an external regulator/rectifier. Just about the only thing I'm an expert on is how much misery can be caused by a dead R/R 2 days into a 15 day riding vacation with my wife.

So the limits of my contribution to this topic basically come down to:

1. I think an OEM-looking solution would be really nice.
2. Modern permanent magnet charging systems are much more compact and powerful than those from the 70's.
3. There's gotta be room to stash a good R/R somewhere on a CBX.
4. For me, "good R/R" means a MOSFET type. The SCR types are cheaper but kill themselves with heat.

I look forward to thoughts from those who know more about this stuff than I do.

[RC 166]

I read about these designs and it seems that around 2004-2007 or maybe even longer most of the makes had problems with fryed stators and flywheels spitting magnets.
If the design is still used, they must have solved all that by now?? What's the performance like (Watts) with these? Also,one have to find a way to attach the flywheel to the primary shaft.
Create a flywheel center with splines and drill/tap the shaft?

[Syscrush]

Here are the parts diagrams for the 2024 CBR1000 and CBR1000RR, respectively:





They aren't the same, but have similar style, for sure. Likewise the VT1100, which is pitched as a sport-tourer which is more likely to be expected to handle additional electrical loads.

Dedicated touring bikes like the Goldwing and BMW's K1600 have large, external, automotive-style alternators, but it seems like the style shown above is by far the most common. All Harleys seem to use it, and you can buy a Harley accessory "High Output Alternator Kit" for earlier bikes:

https://www.harley-davidson.com/ca/en/s ... p/29985-87

This claims to increase amperage by 50%, it includes a replacement rotor/flywheel and regulator/rectifier. Claimed output is 32A, which would work out to almost 400W.

All of the rotors I was able to find pictures/descriptions of indicated that the magnets are embedded in a steel rotor.

This style has been common for a long time, across many different types of bike, I'd be surprised if there aren't examples of good, reliable, high-output systems of this type that can fit in the confines of the OEM CBX alternator assembly housing.

[CBX-tras]

IMHO, the Denso/Kawasaki conversions produce 35Amps that also has the rectifier built into the unit. The brush placement is 90* to the shaft which means the brushes will last a very long time. But, a lot of folks want to keep the looks of the stock alternator. Form follows function. I got over it.
The down-side of the separate R/R of the permanent magnet type is the size of the rectifier that you need to find a place for, and its associated wiring.
If it's decided to use that style, (in my previous research) I found that the Shindengen MOSFET unit is the best one for performance and reliability. If you cheap-out with a no-name unit you may jeopardize the entire charging system.
Shown here on my blown GoldWing with correct wiring connectors. This is the one you would want.

[Syscrush]

I can't agree more on the importance of a good MOSFET type R/R.

On my SV650, I burned through the OEM R/R, 2 cheap aftermarket ones, plus a battery and 2 headlights on my SV650 before finally getting so angry about it that I went a bit overboard: A new OEM MOSFET R/R from a CBR600RR and 10ga wires directly from the R/R outputs to the battery (with a 30A inline fuse).

Since then, every bike I own gets a lot of attention paid to its charging system - including the addition of a 1-LED voltage monitor that's now out of production.

The CBX-Tras alternator conversion fit perfectly and has never given me any kind of problem. One of the best mods on my bike.

[JoeInTUS]

BMW went to an internal alternator on the water cooled boxers and the early version of the stator has had it share of failures. To reduce the probability of failure, some of the cool kids have changed the stock Shindengen FH020AA shunt type regulator to the SH847 series regulator. In theory the series regulator allows the stator to run cooler. The SH847 is even bigger than the FH020AA and more expensive.

Some discussion here (Roadster also sells the LED voltage monitor like you mentioned):
https://roadstercycle.com/index.htm

Another source of Shindengen R/Rs. I have ordered from them and received my order in less than a week.
https://www.easternbeaver.com/Main/Elec ... ctors.html

Wanting to be like the cool kids I have been running a SH847 in my 2017 R1200RT for about 2000 miles and all good so far.

[Syscrush]

Thanks for that, Joe. Looking into it a bit more I found this video that discusses the mods of operation between shunt and series type R/R, which is probably of interest to many reading this thread:



It's not covered in that video, but as far as I can tell, the series type of regulator regulates voltage by fast switching - the working principle appears to be similar to a class D amplifier. When the voltage hits the prescribed target, the stator coil is switched open, which will cause its current (and voltage) to drop.

This is unlike a shunt type R/R, which shorts the stator when voltage hits the target level, which causes voltage to drop, but current remains unchanged. The shunt system results in more current through the stator and R/R, which increases likelihood of heat-related failure.

[RC 166]

Good info about Shindengen RR's!

I am interested in designing a prototype Magneto/Stator type alternator that fits in the CBX engine.

Anyone that know of some late model Flywheel/Stator package (preferably as small dimensions as possible while still delivering 400+ Watts).
I want Flywheel max outside diameter and max width (thickness) & Stator dimensions of portion outside the flywheel.

[NobleHops]

In the USA contact Rick's Motorsport Electrics and they will probably source and build you what you seek. They make stock stators for the CBX, so they know the setup, connectors used, etc. Contact my friend Mike Corcoran there, tell him Nils Menten referred you.

https://ricksmotorsportelectrics.com/

[RC 166]

Nils, you may have misunderstood me. I don't intend to reinvent the wheel here, "just" (ha-ha) build a CBX alternator from readily available modern motorcycle parts.

Hence, I am after dimensions from the smallest 400W + Magneto Flywheel / Stator package found on a suitable OEM bike.
Modern enough to have past its teething problems but preferably already present at breakers.

The ideal person to ask is maybe a forum member working as a MC mechanic, my 2 cents... Please come forward...

[Syscrush]

The ideal person to ask is maybe a forum member working as a MC mechanic, my 2 cents... Please come forward...

The company linked by Nils sells rotors and stators for a variety of motorcycles and snowmobiles. There's a good chance that they have exactly the info you need about OEM charging systems that are more compact than the CBX system.

[NobleHops]

The ideal person to ask is maybe a forum member working as a MC mechanic, my 2 cents... Please come forward...

The company linked by Nils sells rotors and stators for a variety of motorcycles and snowmobiles. There's a good chance that they have exactly the info you need about OEM charging systems that are more compact than the CBX system.

That’s exactly what I was driving at, thanks, Phil.

[RC 166]

My apologies Niels,

I thought you were talking about bespoke stuff. I clicked your link and indeed there are loads of stators, stator kits etc. however not many complete with the magneto flywheel. For every popular 1000cc sportbike I looked at, there were only stators and RR's. I could only see one type of flywheels, for early '73 -'78 Kawasakis, and as far as I know, they are 1-phase systems?

[NobleHops]

That's why I would call or email them, Peter . They are very helpful. Mike is a friend, if you drop my name you will get a little extra special treatment I think.

[NobleHops]

Peter, I just swapped messages with Mike. He suggested that you email the info line to contact the folks at Rick's if you want to investigate any of their resources. Good luck with the project, I will be watching with interest.

info@ricksmotorsportelectrics.com