Help with wheel rim codes

[jpward58]

Hello everyone,

I'm new to the club after having bought a Z1 earlier this month. The bike has a proof of manufacture certificate signed by Rick Brett stating that it was made in April 1973. The majors all hang together nicely but
I'm trying to establish how original the other bits are especially what the codes on my wheels mean. I've tried to find how they are coded by viewing them on websites - youtube etc but they don't seem to fully match what has been published out there. I'd very much appreciate any feedback you can give me to clarifiy this for me. See attached pics Many thanks John.

PS the pics on the red mat are the front wheel

[marmck]

https://www.freewebs.com/750rs/datecodes.htm

[z2.john]

later replacements from 1978 and 1989

[Wrigers]

Hi John, as stated you appear to have a February 78, and a December 89 judging from the photos. Paul.

[jpward58]

Thanks very much guys,

So the 278 signifies Feb 1978 and the 1289 December 89. It all makes sense now.

A long way off 1973 but at least they are original make rims.

Is it unusual to have original rims on a bike so old?

Thanks again much appreciated

John

[Philippe]

Hi John

the rear rim is a 303 which is OK, the front rim is a 305 and that's not so good. The 305 rim was used from the Z900A4 onwards. The wheelhub of a 305 front rim is smaller than the wheelhub of a 303 rim (Z1-A-B).
The spokes have a different angle and using a 305 rim on a Z1 hub could cause the spokes to bent...
You need a 303 front rim on your Z1.
GrtZ
Philippe

[jpward58]

Hello Phileppe

Many thanks for your comprehensive reply. Also apologies for my late response - I haven't visited the club website for a while.

I'll check out the hub v the rim. I've also recently bought a 303 rim from a guy in France. It pre dates the bike (date code 2G) despite its age it is in good condition but it does need a re-chrome. I believe the hub is original so this may well be a fortunate stroke of luck.

Once again many thanks to allfor your help on this.

Much appreciated

John