The following post recently appeared on the Real Classics forum, as it may be of interest to other Greeves owners I have posted it here along with my answer
I am restoring a Greeves 25DC Sportstwin Mk1 fitted with the Villiers 2T engine, I have a problem with the final drive chain, I have been supplied with a 1/2" x 3/8" chain, whilst the pitch seems correct the chain appears to be too wide and comes up against the gearbox casing, the sprocket is very close to the casing, but I can see no way of getting it further out, I have a spare gearbox which has not been messed with, the sprocket on this one is also close to the casing and my new chain fouls the casing the same as the one I intend to use, any ideas? I am completely baffled.
The correct chain should be 1/2 x 5/16 or 428, I think the owner above has measured the outside of link where as the measurement 5/16 is the inner measurement, as there is no 1/2 x 3/8 size.
However the modern 428 size has thicker side plates than the original Renold 1/2 x 5/16 & cuts down the clearence to the gearbox casing & in particular the speedo drive protrusion. I have used 428 on my 25DC and its OK (just) but there is slight rubbing on the gearbox casing speedo drive protrusion. The clearance may vary from one chain make to another, & if there is significant lack of clearance then Renold chain should be used.
I am restoring a Greeves 25DC Sportstwin Mk1 fitted with the Villiers 2T engine, I have a problem with the final drive chain, I have been supplied with a 1/2" x 3/8" chain, whilst the pitch seems correct the chain appears to be too wide and comes up against the gearbox casing, the sprocket is very close to the casing, but I can see no way of getting it further out, I have a spare gearbox which has not been messed with, the sprocket on this one is also close to the casing and my new chain fouls the casing the same as the one I intend to use, any ideas? I am completely baffled.
The correct chain should be 1/2 x 5/16 or 428, I think the owner above has measured the outside of link where as the measurement 5/16 is the inner measurement, as there is no 1/2 x 3/8 size.
However the modern 428 size has thicker side plates than the original Renold 1/2 x 5/16 & cuts down the clearence to the gearbox casing & in particular the speedo drive protrusion. I have used 428 on my 25DC and its OK (just) but there is slight rubbing on the gearbox casing speedo drive protrusion. The clearance may vary from one chain make to another, & if there is significant lack of clearance then Renold chain should be used.