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Re: Mystery chain case hole '54 NH

Posted: Wed Aug 26, 2026 9:02 am
by Vincent.vanGinneke
Hello Dennis, not using the front part from the FERC means all the shit from the rear chain will end up on the rear of the engine and elsewere..
Try to find that part, you can leave the rest of the FREC but using top and bottom chainguards is adviseable...
Fitting the front part from the FERC together with a earlier type top rear chain guard means some fiddling as both interfere at the top.

Re: Mystery chain case hole '54 NH

Posted: Wed Aug 26, 2026 9:06 am
by TonyBaxter
Roger Gwynn wrote: Tue Aug 25, 2026 6:17 pm Where is the crowd of onlookers offering help and asking dumb questions?
It was on the outskirts of a town and I got there not long before closing. I bought some extra tools and they allowed me to use the staff toilet. Shortly after I was the only person left in the car park!

Re: Mystery chain case hole '54 NH

Posted: Wed Aug 26, 2026 10:03 am
by Mick D
Hi Dennis

Worth noting that if you take Vincent's advice and decide to use the front FERC element, you will have to remove the gearbox sprocket to fit it.

Regards Mick

Re: Mystery chain case hole '54 NH

Posted: Wed Aug 26, 2026 12:14 pm
by simon.holyfield
Vincent.vanGinneke wrote: Wed Aug 26, 2026 9:02 am Hello Dennis, not using the front part from the FERC means all the shit from the rear chain will end up on the rear of the engine and elsewhere..
Try to find that part, you can leave the rest of the FREC but using top and bottom chainguards is advisable...
Fitting the front part from the FERC together with a earlier type top rear chain guard means some fiddling as both interfere at the top.
I've got a spare knocking about if anyone wants it...

Re: Mystery chain case hole '54 NH

Posted: Wed Aug 26, 2026 1:16 pm
by Vincent.vanGinneke
a few pictures showing the set up with FERC front part and standard top chainguard.
first two pics show how they interfere.
last pic how it 'fits', keep room between the two as rearchainguard obviously moves forward.
Voorstuk FERC op HS (3).jpg
Voorstuk FERC op HS (4).jpg
Voorstuk FERC op HS (8).jpg

Re: Mystery chain case hole '54 NH

Posted: Wed Aug 26, 2026 2:52 pm
by Simon.Gardiner
Apart from the chaincase inner the rest of Dennis's bike is 1955?
(Oh dear - cue discussion on gearbox mainshaft lengths and drive-side engine mainshaft lengths?) :roll: :twisted:

SG

Re: Mystery chain case hole '54 NH

Posted: Fri Aug 28, 2026 9:09 pm
by dennis.t
Thanks everyone for the advice. I actually have the front part of a FERC but I am not going to fit it. I no longer ride my bikes but I do enjoy saving basket cases and restoring them. Geoff Brown provided the gearbox and clutch from club spares and they all fit together perfectly.
I have blocked the ‘mystery hole’ with a mushroom headed bolt from the inside. The next owner can fit a FERC if they want to.
Dennis

Re: Mystery chain case hole '54 NH

Posted: Sat Aug 29, 2026 7:08 pm
by Simon.Gardiner
Dennis
I think you're using a '56 bottom end in the NH, it should have the longer drive-side mainshaft (allowing the chain line to be moved outwards to give clearance for the FERC behind the primary chaincase).
Did Geoff give you a 56-on gearbox with the longer gearbox mainshaft to match with the later chain line?

SG