Talk Morgan Forums Morgan Sports Cars Morgan Three Wheeler & Super 3 rear sprocket

Dear All,

Over the past 18months many of the car's parts and systems have been refined and improved: Bevel box, rectifier, exhausts...
My attention now moves on and my next interest is getting the rear sprocket perfected. A sign of progress perhaps.

I have just replaced my rear sprocket after around 9000 miles. At £450 plus labour, it is not insignificant; 5p per mile or about a third/quarter of what i spent on fuel over the same distance.

It seems a bit silly that it only lasted as long as the rear tyre.

In the attached picture, you can see the tooth degradation on the old sprocket.

The new part is the same aluminium flawed design.
I know that in 9000 miles i will have to replace it again. I am aware that i am not the only one who suffers from sprocket degradation. I have seen or heard about a number of people considering a number of different solutions:

Mitigation:
- placing a metal deflector between the Bevel box and the rear sprocket

Changing the material:
I am interested in tougher/harder material.
I assume hardness is the technical term.
- steel
- plastic polyurethane casing a la supermax? http://www.supermax.net/ (still waiting for Michael H's review)
i assume that this is not patented and i can get it done in the UK
- plating with a hard material????

Improving.
My worn sprocket weighs 2.65 Kg.

Is anyone else interested in joining getting a batch made out of a hard steel alloy?

I have no commercial interest in making sprockets!

I just want to save money and wonder if anyone can add more knowledge. Perhaps you would like to work together to find a solution as casting is expensive.

Im in, that company does look professional. I believe my sprocket is starting to wear down.

[quote][/quote]Mitigation:
- placing a metal deflector between the Bevel box and the rear sprocket

I have recently had a go at this. It hangs from the lower SA attachment and uses one of the existing mud shield bolts. It'll take some time before I know whether its doing any good, but it makes me feel better

http://tinypic.com/r/2qmkajc/8

What is the reason for the deflector plate?

my rear sprockets were more worn than your 10,000 / 11.000km, I am trying to finish the third pulley and I expected a fourth pulley as collateral, the third pulley I buy on ebay 119$/150 euros with the delivery to date it has increased by 70%
http://www.ebay.com/itm/BDL-Solid-Full-P...=item3a9efcb999

I have the properly adjusted, it will not last longer than the original

if no term solution in the rear pulleys envisaged by morgan ssay I'm going to make a steel rear pulley that is attached to the pulley original aluminum, the problem is that I own than conventional machines, it takes a lot longer than in digital machines.

I think I want to have laminated laser cut steel
or
steel with a electroless nickel boron coating

A steel sprocket from Morgan may not be too far off, Nippymog has a trial one on his car according to his post in "Morgan performance parts" a few days ago. It may be worth a call to them, particularly if they are still selling the alloy sprockets that are "not fit for purpose". You did well getting 9000 miles out of it, my first one only lasted a little over 3000 miles and the warranty replacement is not doing much better.

I had a hard anodised dural pulley made. As suspected the anodising didn't last long but I have very little wear at 3000 miles. Still screams however. I have a steel one in the pipe line. As you say Morgan are testing steel and I'm sure it will cure the problems. Steel won't be cheap as the machining time is a factor.
I can occasionally be found rubbing the rear pulleys on Harley's when I see them parked up. I can confirm they suffer the same type of wear but not to the same degree.

The answer is ditch the tooth pulleys and fit a pair of sprockets as HFS MORGAN did.Tooth belt drives are ok on hard tailed Harley tractors but useless on a M3W.
A lot of the problem with bevel boxes has been created because we have to run the belt so tight that the action of the swing arm tightens the belt even tighter and puts a massive strain on the bearings of the hub and bevel box.MGP BIKES RUN CHAINS AND THEY TURN OUT CIRCA 250 BHP!.
I will convert mine to chain drive when I can find the time from tuning race engines etc.
Davidg

At last someone who knows what they are talking about, well done David G. Our old Morgans used to go for many thousands of miles with good old chains and sprockets, talk to the bikers who have a lifetime of experience of chains and sprockets. You don't see that many proper race bikes with belt drive, I wonder why.
still I am only an old prat who makes his own pulleys and sprockets for high end drag bikes. Good luck to the maker who comes up with an ultra high price bolt on goodie for what is basically still a 1930s trike.