Alton Makes Good...really fast!

I would be interested in the weight of the magnets and the dimensions of the retaining band if that were easy to come by.
With the large diameter of the rotor it is going to require a pretty substantial retainer to keep it together at 7000 rpm.

hobot said:

External? As in outside case or not directly on crank end? Anyway we are grassing at straws why this instant case lost magnets so my long distance suggestions. I don't get rotor/stator fouling in my stock Combat nor hotted up to take it Combat Peel well into red zone - until way beyond rpm the tach could register or regular Combat survive at all. Now if a Commando was made to be a pussy cat to kick over there'd be no need of wimpy alternator with wimpy exposed edge magnets to fit a starter. Peel will have 600 watt juicer to help all weather operation and other gizmos and tiny battery topped off.

I've studied the windpower guys DIY alternators and been into lawnmower style and have little faith in glue or epoxy to hold magnets once heated and spun up.

This is only way adhesives have half a change to retain magnets

Click to expand...

I use an external rotor similar to the Harley rotor in your picture except mine is a lot smaller in diameter and the magnets are thinner. The stator is inboard of the rotor and attached to a plate that fastens to the original stator mounting studs.

mike996 said:

The clearance is .4mm per Alton and they supply plastic shim material for this purpose.

Click to expand...

.004?
That's a pretty tight gap to hit (not much room for error).
If I remember right, a stock Lucas gap is .008.

Jim,
from the pic that he posted in the other thread, they look to be pretty small magnets, although there seems to be a bunch of them.
The retaining material (ring?) also appears to be pretty thin.

I wonder.........(just thinking out loud) ,if the design of the system couldn't have played a part.
It seems that having the starter chain attached to the rotor could amplify any wobble considerably
or possibly even flex the 4 1/8" dia. rotor to the point of contacting the stator poles.

Mark said:

mike996 said:

The clearance is .4mm per Alton and they supply plastic shim material for this purpose.

Click to expand...

.004?
That's a pretty tight gap to hit (not much room for error).
If I remember right, a stock Lucas gap is .008.

Jim,
from the pic that he posted in the other thread, they look to be pretty small magnets, although there seems to be a bunch of them.
The retaining material (ring?) also appears to be pretty thin.

Click to expand...

Yeah, that's kind of what I thought.

.4mm clearance would be .015 inch and should be plenty. Jim

mike996 said:

My wife's suggestion re all this earlier today at "Christmas Eve" dinner was: "Why don't you just buy a new Ducati?"

Click to expand...

What a great idea! All that handling and braking and good looks too. Let's see, which model would have room to fit a Commando engine and gearbox into?

Ken

comnoz said:

I use an external rotor similar to the Harley rotor in your picture except mine is a lot smaller in diameter and the magnets are thinner. The stator is inboard of the rotor and attached to a plate that fastens to the original stator mounting studs.

Click to expand...

sounds like a pretty good idea to me - any pics?

Mark said:

comnoz said:

I use an external rotor similar to the Harley rotor in your picture except mine is a lot smaller in diameter and the magnets are thinner. The stator is inboard of the rotor and attached to a plate that fastens to the original stator mounting studs.

Click to expand...

sounds like a pretty good idea to me - any pics?

Click to expand...

Here is the edge of it.

" I would be interested in the weight of the magnets and the dimensions of the retaining band if that were easy to come by."

I should be able to provide that info in the next day or two. I think I have recovered all the magnets and measuring the retaining ring is easy enough. I don't have a scale or a caliper here but I do at home and we're driving back home tomorrow and I'm carrying the parts there to ship to Paul at Alton.

mike996 said:

My wife's suggestion re all this earlier today at "Christmas Eve" dinner was: "Why don't you just buy a new Ducati?"

Click to expand...

Did you just look at her and ask if there was room for another bike?

Heck, she's already said we should go look at some Ducks next week - there's a dealer nearby. I"m the idiot who's saying, "Nah, I don't really want a new bike."

"I wonder.........(just thinking out loud) ,if the design of the system couldn't have played a part.
It seems that having the starter chain attached to the rotor could amplify any wobble considerably
or possibly even flex the 4 1/8" dia. rotor to the point of contacting the stator poles."

The starter chain and sprocket do not rotate or pull on the assembly when the engine is running due to the sprag clutch and the starter chain is quite slack. The only time the chain/rotor sprocket rotates is when the starter is engaged. With the engine running I don't think it would have any impact on the rotating assembly at all but OTOH I don't have a clue of the dynamics of such a system.

Jim C -

The Alton rotor/sprag/sprocket assy weighs 10,220 grams. The rotor itself (the part that actually rotates with the crankshaft) weighs 600g, the magnets/retainer add approx 50 more Grams for a total rotating rotor weight of approx 650G. The rotor itself is 98mm in diameter and with the magnets/retainer, 106mm in diameter. The sprocket is considerably larger in dia than the rotor but it does not rotate in normal engine operation.

The Lucas RM24 rotor is 700 grams, and is 74mm in diameter.

I'll try to post some hi res pics tomorrow.

Ya know it be good idea to install w/o the coil ring but with some witness material around the rotor and give is some red line zing up on padded center stand or a ride with just a topped off battery. Maybe a few crayons not quite touching and then see if any did and how much. Might be apparent just looking w/o coil packs on. Sticks of solder? Poster board? Clay packed around coils? Playing cards taped on till playing ...

mike996 said:

Jim C -

The Alton rotor/sprag/sprocket assy weighs 10,220 grams. The rotor itself (the part that actually rotates with the crankshaft) weighs 600g, the magnets/retainer add approx 50 more Grams for a total rotating rotor weight of approx 650G. The rotor itself is 98mm in diameter and with the magnets/retainer, 106mm in diameter. The sprocket is considerably larger in dia than the rotor but it does not rotate in normal engine operation.

The Lucas RM24 rotor is 700 grams, and is 74mm in diameter.

I'll try to post some hi res pics tomorrow.

Click to expand...

What is the thickness and width of the retainer. Is it stainless. [non-magnetic] Is the retainer band all that was keeping the magnets from flying out radially from the rotor? How many magnets and were they in groups of several magnets or were they evenly spaced? Jim

mike996 said:

Heck, she's already said we should go look at some Ducks next week - there's a dealer nearby. I"m the idiot who's saying, "Nah, I don't really want a new bike

Click to expand...

The problem with buying a new Ducati, aside from cost, is that you will need to go into a Ducati Dealership to do this.
Having just purchased a used Triumph from a Ducati Dealership's bargain bin, I was invited to go across the road to tour the actual Dealership., while waiting for paperwork.
They had that awful Eurotrash technopop dance music pounding away at about 110 db nonstop with no change in the song for the half hour I was there.
The place is all done up to look like a nightclub, with expensive new motorcycles as decorations. They even had a little specialty coffee shop in the corner complete with a perky twenty year old Barista. I think all of the staff members were perky twenty year olds full of caffeine.
The salsesman walked me over to a large room set up as photo studio with fake cloud backdrop. There was some sort new Ducati Sexarelli set up in a provactive pose in there. The salesman proudly told me " Every customer gets a photo taken with the bike they've bought" He hesitated and then added "Italian bikes only"
Rule number one in salesmanship- Never make the customer feel that he/she is not worthy- It would have been a smarter move on his part to avoidcthe photo booth, but it didnt really matter in this case, I was happy to get out of there before the headache really set in!
I still think a motorcycle shop should look like a place where motorcycles get worked on, not like some sort of leftover 80s disco.
But I got what I wanted from the, a really nice 05Triumph Daytona 955i in almost new condition for not a whole lot of money.

It's the wank factor that stops me going into Ducati dealers in oz too.
Nice bikes but the matching Ducati full leathers and helmets that are seen walking in to have coffee and a pose,,,,,
Looks like most never see a mountain road or rain or they'll get dirty and have to leave the lounge.
I think I'm getting old,

In the 70's it was pay the shifty salesman and piss off, if it broke it was your fault for buying a Ducati.

graeme

Replacement parts arrived from Alton in Mexico city this morning - mighty impressive support!

I'm not in town today - we are in Cancun for a week but just wanted to advise folks again that it would be impossible to provide better customer support than Alton has!

Quote: The clearance is .4mm per Alton and they supply plastic shim material for this purpose.
mike996

For the record, according to mike, the clearance is .016", not .004 as someone translated. More than stock I believe.
JD

It wasn't translated as .004.
I just questioned as to whether it could have been a typo or not because even though .004 seems awful tight,
.4 seems equally excessive in the opposite direction.

I checked Altons installation instructions and their correct rotor/stator gap is .016.
Which incidentally is twice as wide as the stock Lucas alternator.

I have never seen a Alton ES setup in person although I would very much like to. The rotor / sprag piece in particular.
The whole idea I find very interesting.

From what I have read on the internet, Mikes issue is not the first for this product.
I am curious as to the cause for such failures.

http://www.norvilmotorcycle.co.uk/Start ... sembly.pdf

Although 0.4 in metric is around 0.016 in imperial it pays to work in what the manufacturer states to avoid problems in cross overs if you are used to working in steam.

As far as newer Ducati's it might be worth taking a test ride on a Hypermotard 1100S (or even the 796)
As far as most bland in general cookie cutter contemporary motorcycles go, they are an exception (imo) with old school character.