new primary chain

[Bernhard]

‘’I dont know if you are aware but there are conversions available ( at least there were ) in the UK with sprockets to take Duplex double roller chain which is easy to source.’’

Hi do you know where I can get this Duplex double roller chain & sprockets?
Most of the parts from Honda dealers have all but dried up.

[G-Man]

http://www.novaracing.co.uk/honda-cb727 ... d-road.htm

Scroll down.

G

[GORDON BROWN]

Hello everybody

There is also Moore performance engineering www.mpe07.co.uk who also do them, I think possibly to order only.
Though they were originaly intended for racing I would think they would be OK on the road, I have only ever used one on a racer so I dont know how they will last / stretch etc. over a distance and there is the cost.
Has anyone on the site actualy had one break in normal use ?
I have enclosed a picture of the assembly.

[sprocket]

I think the size of the chain in question is 3/8 x 3/8. If you look at standard drive products (www.sdp-si.com) and search for part no. A6Y77-37 you should find chain of this size. The only problem that I can see is that it is stainless and I don't know if it matters. On the other hand if your origional chain is bad the sprockets are probably bad as well and this is all a moot point.
Yours,
Karl

[Phil-UK]

Hi

There is a company here in the UK called Sprockets Unlimited who have found a source of chain.
Its the correct pitch but has thinner side plates than the original but it is available. I've got one on my CB72 after the used original started shedding bits of bush.

http://www.sprocketsunlimited.com/

Don't think you would want to use it for racing but from what I've read the original chain wouldn't take that anyway.

cheers

Phil

[Bernhard]

I think the size of the chain in question is 3/8 x 3/8. If you look at standard drive products (www.sdp-si.com) and search for part no. A6Y77-37 you should find chain of this size. The only problem that I can see is that it is stainless and I don't know if it matters. On the other hand if your origional chain is bad the sprockets are probably bad as well and this is all a moot point.
Yours,
Karl

I think the chain size is not quite compatible with anything made in the west, the dimensions I have got are:

Width .378
Pitch .372
Roller Dia 6.30mm (.244 inch)

Note; std 3/8 x 3/8 chain has only 6mm rollers!

Which makes this an odd size, the best description I have heard is that is a
‘‘bastard size’’ ( I wonder who was the first person who used this expression?)
Those Japanese engineers must have had a fun day designing this motor, perhaps it was done by the Honda founder himself, Soichiro Honda, we will never know.
I’ll bet he is laughing in his grave about this.

[sfcrgs]

Hi all,
I know someone in UK who may have these chain.
He asked me the very precise description.
For the primary chain, but also the distribution chain.
Give me the descriptions, and I give you the answer.