Chain Milling Away Selector Box

[Duccout]

I have a problem with the 350 which I am hoping someone may have encountered...... The chain is milling away the boss which holds the small bush at the back of the selector box. I thought that it was due to the 530 chain and sprockets and would stop when I changed to 428 size, but it has not and it has probably milled away about 2mm of the alloy and the bush on one side.

The sprocket is located by the gearbox bearing and the selector box by the crankcase, so what is happening? Has anyone else come across this?


Cheers,

Colin

[LaceyDucati]

Colin

Most modern 428 chains used are "Heavy duty" and have wider side plates which makes the situation worse. Later Mototrans models usually have the boss and bush reduced to allow the 530 chain to clear. All I would say is they all do it to some extent and it will stop once it's found it's way. I quite often shorten the housing back a bit to tidy it up. Chains vary in width, so maybe be selective with chain choice and leaving the 0.5mm "thrower" washer out behind the output bearing (if you are using a sealed bearing) will also help.

Regards Nigel

[Duccout]

Thanks Nigel,

That has reassured me a bit. I will clean up the boss a little with the Dremel.

Cheers,

Colin

[blethermaskite]

Colin, yes I have come across this issue a number of times, there's not much room in there, so chain alignment is a contributing factor make sure your sprockets are dead in line with each order,
Cheers,
George

[themoudie]

Aye Colin,

Happens on the 450 MKIII as well, as George suggests, get the chain alignment as good as you can and don't run with a slack chain or over-worn sprockets. I will post an image, for reassurance!

Good health, Bill

[Duccout]

I think that Nigel hit the nail on the head when he pointed to chain width. In the past I always used Reynolds chains which were much narrower.




Colin

[Duccout]

Looking at the chain today I can see that it is the spring link that is the main culprit, which is not very good for chain safety, and I wonder if this problem is a reason for Ducati Singles breaking their chains? Anyway, I will see if I can fit the spring link on the other way around, with the spring on the back.



Colin

[Andy Higham]

I have fitted one of the Sports Motorcycles selector boxes as everything inside mine was sh***ed. I can now fit my finger between sprocket and selector box, so plenty room.
https://sportsvalve.com/ducati-single-4 ... ector-box/

Less than a week from ordering to delivered

[Duccout]

Hi Andy,

Let us know how it performs.



Colin