1983 31/2 master cylinder

[barney 66]

Hi, I have a 83 31/2 sport with an aftermarket master cylinder on the front, I have put a different top yoke with flatter bars for more of a strada riding style trouble is cylinder is now on quite an angle.
I do have (I think original grimeca cylinder) but can’t see where a brake light switch would go, did they have one or should I look for another cylinder altogether?
Thanks barney

[MickeyMoto]

If there are no terminals then it will not have a brake light switch. The later ones had one. I got around it by buying a banjo with a pressure switch. It makes the banjo longer but it did the job.

[barney 66]

Thanks for the reply, so do you think the long pressure switch that Mdina italia sell will fit ? it looks to me if I swap the bolt holding the brake line on for the switch it could work
Thanks barney

[Morini Jen]

Hi Barney.

If you mean the one in the attached photos, yes, that should work, although as MickeyMoto said, it will add to the length and you may find it tricky to clear the clocks.

Of course it will only work with a single banjo.

[Morini Jen]

Having said that it would work, it's fair to say it's not the subtlest of items to perch on your handlebars. My 1983 3½ K1 Sport has triple discs so I've measured the rear brake light switch for you. I'm sure there are much more discreet switches available (although I can't remember the thread size off the top of my head).

My front brake is the original Grimeca master cylinder and when I first bought the bike it had clip-on bars. I now have higher bars and as you can see the master cylinder looks comfortable, but with twin brake lines there is no way I could fit a brake light switch with the standard clocks. Not that it bothers me. If I think someone behind needs to see a brake light I just dab the back brake.

It may be worth your while looking for a more attractive front brake light switch. I'm sure someone can enlighten us as to the thread size.

[barney 66]

Thanks for the detailed reply, that was the switch I was looking at and mine is single disc so only 1 banjo, I think you are right about the clocks I will look Tomorrow and yes not the best looking, if there was something a little smaller
Thanks barney

[3potjohn]

My K1 has a screw in stop switch in the brake lever perch.

[barney 66]

Any chance of a picture please ?
Thanks barney

[George 350]

Hi Barney,
Is your bike single or twin disc at the front?
Regards,
George

[barney 66]

Hi George, it’s single disc

[George 350]

Hi Barney,
An alternative worth considering is from the Gilera 4Runner scooter. It has a smaller bore than standard (13mm) and it has improved the front brake from being merely adequate to quite good on my Strada.
I particularly wanted a Grimeca/ Italian one as the bolt/hose thread is 10x1mm as per original which meant I didn't have to change hoses. It also has unobtrusive brake light switch underneath. See:
https://www.imagebam.com/view/ME12OPLIhttps://www.imagebam.com/view/ME12OPLJ
Cost? This one was £20 Inc postage on ebay and rebuild kits are available if necessary.
Hope this helps,
George

[Rocker62]

Hi Barney. On my 500 Sport and Laverda triple I have fitted Triumph Sprint ST 955i front brake master cylinders, eBay £22. I obviously have twin front discs on both. The original front braking on both is very good, Grimeca and Brembo, but let down by wooden operation which needs hauling on for maximum effect. The Triumph master cylinder works with the original brake lines and banjos but you will need the Triumph banjo bolt, thread is different if memory serves me. Other Triumphs master cylinders will probably do the same job, as will 90s Ducati Supersports. May not be original equipment freaks cup of tea, but hey ho.The braking then becomes a lovely one finger job for most situations. The Grimeca fluid reservoir screw cap fits as well which fools some !

[barney 66]

Thanks you both for the detailed reply’s, George that looks small and neat, just looking at those now,
Thanks again
barney

[scbond2@yahoo.co.uk]

Has anybody tried the MZ master cyl ?

[70sbikes]

A cheap master cylinder from AliExpress works very well indeed (their braded steel brake lines are good too!)