Ouch!

[Leslie.Ore]

Primary chain does a Harry Houdini,see main chat for further details

[john.whiting]

Why do Ariel primaries get smashed by chains letting go.?Ive never seen any other bike with it happen,and Norton twins even 750s had the same 1/2" chain.Of course ,they had steel primaries.But Ive also never seen a BSA,Matchy or Tri 650 case smashed.It seems common in the fours too.Why?

[adrie.degraaff]

It seems common in the fours too.Why?

In most cases; not enough oil, the chain won't last 500 miles when dry.

I can see it has a one part footrest, so 1954 and a twin .

[Leslie.Ore]

1956

[alan.moore]

Les,
Could you work out from the broken chain why it failed?
What sort of mileage did it have on it?
Cheers
Alan

[nevhunter]

That single row chain is doing a big job. Only use a good quality chain and a 1/2 link often has to be used which isn't a good idea. Split rollers are a no no . They end up in the bottom of the case in large numbers. Nev

[Leslie.Ore]

A case of tired chain and not enough lube,had great difficulty getting cases oiltight,so just sprayed sticky lube on it each time I went out on it.Obviosly wasnt enough.Have brand new chain now with no half link involved.Will try and get cases oiltight when I sort it.

[tonyh]

I changed mine last year on my 59 VH. It's been on since 59 and done over 60k miles (don't shout at me, it's not a lot). It had little stretch but it is in oil and that nice engine shock absorber is the key. Let um run dry and I think we know the outcome.

[Brian.Fosh]

I was advised to use Regina or Iwis by the "Chain man" a few years ago and indeed find both makes particularly good.

It turned out that there is a lower specification for chains that even Reynolds adopted to compete.

I had no noticeable stretch on my SQ4 primary this year when it reached 1500 miles.. before stripping it to fix a moving main bush. (all fixed now)

Brian.

[nevhunter]

Once a chain has been bedded in it hardly needs adjusting further if there's enough oil in the case, unless it's misaligned or too tight. When adjusting the front chain , check it with the rear chain forced tight by a broom handle or such and leave the tensioner pushing the gearbox forward slack wise, as the rear chain has more load on it than the front and tends to pull the gearbox rearwards in use. Nev