Curvy Rectifier Repositioned using cheaper compact Honda RF

Fitted a new Honda rectifier as a replacement and repositioned it to the left hand side of the bike using a custom aluminium adapter plate. Its all connected and theres 14.48v being returned to the battery or 14.28v with the lights on. I ride with the light on all the time now as it may reduce the input load and therefore the amount of work the rf has to do ? Light bulbs are cheaper than rectifiers.

Ordered the 2 parts from Hong Kong; Honda shunt type rectifier £20 plus £6 for the Honda type connector.
http://cgi.ebay.co.uk/REGULATEUR-RED...item230a0fbd37
http://cgi.ebay.co.uk/Regulator-Rect...item27b26296a2

Looking on the Honda forum sites they seem to suggest that the newer vaned type is more reliable but I think mounting it on the adaptor plate / heatsink should improve its ability to remove heat and improve its longterm reliability. I didn't get the vane type as I didn't think it would fit under the carbon fibre cover. [In hindsight i think it would be fine]

Got hold of a 2m square sheet of 5mm aluminium plate from a local "old school" DIY shop. Made up a cardboard template of the available slot. Cut out the aluminium. Taped the required holes for the rectifier bolts (6mm). The back of the bolts are additionally secured using nylon locknuts. Its connected to the frame using the large 10mm (changed the 34mm to a 40mm length) frame to seat bolt at the bottom left hand corner of the first attached picture. The aluminium plate actually slots into a grove in the plastic of the back wheel undertray very nicely.

Put a blob of electrolite paste between the metal back plate of the RF and the aluminium hanger. As can be seen in the 3rd picture, it fits nicely under the grilled plastic cover.

Big grin.........

The main aim of this mod has been to hopefully improve the longevity of the RF. Move it away from rear brake line and also make it cheaper to replace if it does fail again. Another plus is that I can get at the rectifier easily, its only a 4mm allen bolt away.

You can also slip your hand behind the plate easily to guage how much heat its pumping out.

NB: What I've learned from this is that you can use almost any rectifier (5 wires; 3 stator, black & red) because all its doing is converting the input load, AC to DC. Its the physical windings on the generator that dictates this voltage input/load.

At some point i'm going to get hold of the £9 LED charge indicator from sparkbright and mount to the right of the of rectifier behind the grill. little demon eye sitting behind the grill.

http://cgi.ebay.co.uk/12v-Battery-Ch...item230967869f


If anybody fancies having a go at this themselves, i've got lots of 5mm aluminium left over and can easily make them up the adaptor plate and include some M6 & M10 nylon locknuts. Your'll need to source the RF and lead.

[Viney]

But your legs sit in front of those areas, receiving as much as or less airflow as it did in the old place? Also being a non viened rectifier you now have less surface area to disapate the heat! If it works, then cool (No pun). But i'll stick with where mine is placed for the time being and replace evry 50k or so!

Here is a picture of where I positioned mine, front right hand side. You can just see it poking above the fairing.

Thats a nice and tidy (clean) bike you've got there Hardhat for an old curvy. Its reminds me of the John Player special Black & Gold livery of the past. Its hard to make out how you've mounted it onto the frame ?

so is overheating a problem for the standard rectifiers then? ive read they can be a problem, but i dont know why they fail?

When I took my side panel off last week the rectifier was just hanging there unbolted, maybe that keeps it cooler looks like its been that way a long time too.

wouldn't say overheating more like overcharging

[yorkie_chris]

Overcharging... undercharging... catching fire...
All problems due to it being old-tech regulator rather than new MOSFET which puts out much less heat.

If this honda one is shunt type, it is possibly dumping all excess charge in the generators coils. I'm not familiar enough with them to say whether this will cause damage... be interested to hear how it lasts.


Still, if it was me doing this job... the fact that it works now does not mean it is a reliable and robust fix. I told you this before you did it. If it was me doing this job I would follow advice given by D'Ecosse here in this thread:
http://eviltwinsbk.com/forumz/index.php?topic=276.0

Thanks for clearing that up for me

It is possibly dumping all excess charge in the generators coils

strange thing for an engineer to say ?

Surely the only place where excess charge is being dumped is either the rectifier (as heat) or straight into the battery (overcharging). Isn't this the reason why RF failure often goes onto to kill the battery as well. As it did in my case.

Been speaking to a Electrical engineer lecturer and his take on it is, its all down to the rectifiers ability to handle spikes (original build quality / oem specification). But he did agree with me that excessive heat is the big killer of circuit / diode longevity (KISS).

Like most situations in life there is always more than one way to 'skin a cat'

[yorkie_chris]

Why strange for an engineer to say? For one thing I do not see any reason that could not be possible, for another, my degree is in Mechanical, not electrical... I have only a fairly basic understanding of circuits, hence why I defer to D'Ecosses understanding of it!

If it is dumping the excess heat into the reg rec then the unit you have looks less capable of handling that heat. Does it get hot in use?
Yours is obviously not overcharging so you think it must be removing all excess energy by heat?

Are those voltage readings you give at tickover, or higher rpm?