What year front end / brake set up is this?

[Norton7d]

Just bought a 71 with a dis brake, it was my opinion disc didn't occur until 72?
It has a 73 inspection sticker, so I assume its either. 72 or 73 front end?

 

[mrtwowheel]

I see what you mean by the inspection sticker. That front axle must have been too long, they used a big nut for a spacer.

 

[Mailman]

It sure Looks like my XS2 front end.

 

[willis]

Master cylinder looks like possibly a ‘75???? Not sure what other years it was used on. Where is the brake light switch on it?

 

[TwoManyXS1Bs]

Kinda secretive pics there.
I see an XS1 throttle, and a gold fork ear.
Bottom bracket (triple tree) shows 2 mount holes for hyd brake splitter.

I smell mix/match...

 

[MaxPete]

On the early disc systems the brake light switch is a pressure switch down on the manifold on the lower triple. It’s not on the lever as on later bikes.

 

[GLJ]

Definitely a 72. Big nut and square washer are on the shaft that the rotor rides on. Rotor looks to be a 72. Master cylinder may be aftermarket should not have threaded hole for mirror. The break light switch was on the bottom side of the master cylinder on a OEM MC.

 

[GLJ]

I see an XS1 throttle, and a gold fork ear.

I smell mix/match...

A 72 would have a kill switch on the throttle.
2M is right. Looks like someone put a 72 front end on a 71.

 

[gggGary]

That 72 front brake is a one year only deal. You will no doubt get the chance to find out why. It's not awful, just needlessly complex. Hint; watch out for the rubber bumpers. There's a seldom applied service bulletin for that!