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RE: 71 T120R
I'm considering getting a front brake cable without the brake light switch. I can squeeze the lever till it hits the bars. I don't want to loose the brake light. I suppose I can use any aftermarket grip with a switch and use a combination horn & directional light switch. Just wondering if there is something out there that would have all three switches, horn, brake light & turn, incorporated in the lever.
Thanks,
Sam

Why would you want to blow the horn when you squeeze the brake lever? The cable with the switch built in is way too light weight. The rear brake light still works so I use a heavy duty cable with out the switch. Far superior stopping power. Plus you don't have to take up the slack in the switch to start stopping.
No such switch like you want exists for all I know. Bikes before 1971 had NO front brake light switch. In 35 years I've never had a policeman ask why there was no brake light for the front brake. I almost always use both brakes to low down or stop.

I agree with desco, but if you insist on having a functional front brake light switch, it isn't hard to make. I did, which proves it.
I discarded the cable operated switch long time ago due to the mushy feel and poor performance of the brake. Most of the effort applied on the lever seemed to dissipate in the rubber switch.
The micro-switch is something out of China, I bought a bundle for very little money. It's crudely clamped on and the prong butts against a bolt head as shown.
It works well for several years now, mission accomplished. It doesn't really show either, crude though it is.
Let me add that I didn't do it because I felt I needed it, it's just that the two brake light connectors became redundant and I couldn't stand it.

SR

Don’t know how well it works but Smart turn (uk company?) advertised on Facebook or via email to me about an engine braking detector..
It seems to be based on an accelerator /decelerator that is wired into your brake light and realises when you engine brake, turning on the light?
Not cheap at £70 odd but if it works, could help

They sold something like that in the USA decades ago, I believe. The light flickered and the harder you braked, the faster it flickered. It was supposed to catch the attention of car drivers behind you, and I guess it did. It never seemed to really catch on as I recall?

SR

Many Japanese bikes use these brake switches:

All late model Yamahas have them. You can probably get them at a breaker for cockles.

Hi srap, Personally I like having front brake light switch.

If you look at switch you'll see the disc with connectors is spring loaded with a rubber washer on the only one I ever took apart. The cable housings nest into ends of the housings. So when you pull lever the cable housings squeeze the plastic switch together, moving the disc with connectors, compressing rubber & a brass washer touches contacts. However this may be aftermarket cable...

So there is lost motion in the switch. About 1/16 to 1/8th inch ish of cable travel.

The inner wire is one piece. Inner wire can get stretchy. It seems when cable strands fracture it starts in the center wire strands, then moves outwards. So inner wire can look ok, but be compromised.

At the same time the housing can get distorted. The housing is wire wound like a spring, covered in a plastic sheath. If housing is stretched or over bent at some time the "coils" can separate making little gaps. So they must be compressed before you get power to lever arms. Again lost motion.

If cable ends are loose in lever (including lever adjuster) an at lower end at backing plate, all this looseness must be taken up pulling lever before power happens, adding to lost motion. All lost motion means more lever travel is needed. Of course brake shoes must be properly adjusted as well. Too loose, more lost motion. Worn pivots, cams can add to lost motion as well.

So you have upper cable housing, the switch, lower cable housing & a solid one piece inner wire.

So before jumping to conclusions about what it needs, it's important to examine all the components & see where your lost motion is & where your stretch is happening. Give the lever good hard squeeze. Look for cable stretching & housings compressing & how much switch compresses. Also look for the lost motion at every component.

We rode these 71 & 72 bikes all over the place & never gave front brake a thought. Maybe not as good as the '68-70 twin leading shoe, but they weren't horrible.

At the same time the original asbestos brake shoes worked really well. Not so good for the lungs, but actually stopped good. The new version asbestos free, seem to take a fair bit more lever effort. You can buy a much stronger stopping lined shoe, but for the first 10-15+ applications of front brake wants to lock front wheel. Not so good on wet street! Once warmed up, which can take several more careful applications on 30f day the shoes work/feel good. I can't recommend these. I cannot find the receipt for where they came from. This on .69 Bonnie with switch in cable.

So just getting one piece cable without switch may leave you disappointed. The only difference is the saved motion from no switch. Vintage Triumph supply sells a Barnett cable with switch. Is that cable stiffer/stronger? I don't know. There clutch cables are kind of skinny looking, but very, very strong. The inner wire is mill rolled which makes it stronger, but skinnery. So you can't just go by looks.

To replace the switch you must take an end off inner wire. Easy to remove. Just heat solder & pull off. Going back on you better know what you are doing.

So look it all over, that will help you decide what best solution would be other than buying modern Bonnie.
Don

Don, while I agree on most of what you say, I don't agree that all you lose is some motion. A trait of these switches is that they won't bottom out and become solid once contact is made. They continue to compress for a bit more, and the force transmitted therefore reduced to the "spring rate" of the rubber. I always found that a one piece cable improved both feel and stopping power. Longer brake arms will reduce the force needed on the lever on account of extended travel and and even mushier feel. A non-switched cable will mitigate this, giving you a still softish lever but much improved braking.
I once measured up the 68-70 brake and compared it to the conical hub brake and found that I needed to extend the cam levers by 35mm/1.38" to bring the "conical" to the same overall ratio. Measuring cam attack points etc. isn't straight forward, so it took some eyeballing. 35mm turned out to be a bit generous, around 25mm, or 1" to some in the developing countries, would probably suffice, but I now have a very nice front brake that will take the emergency out of a hard stop, though maybe not two times in a row. That's on a Trident, a Bonnie takes much less effort to stop.
I have plans to fit modern linings, but as long as the original type works so well, it'll have to wait.

SR

Hi SR, I changed my front brake cable on my '72 Daytona a few thousand miles ago and fitted a Doherty non-switched type, as I had done with my '70 Bonnie "back in the day", to improve the feel of the TLS brake by fitting a switchless cable. My complaints against the switched cable now, as then, had been:

A degree of sponginess when applying the brake, which affected the feel of the brake, no doubt (as you indicated), due to the switch being unable to bottom-out with a solid stop. The loss of motion was there, but was not the major issue, for me.

With the good stopping power of the TLS brake, the brake light would only activate under the pressure needed for a hard emergency stop. This takes away most of the safety benefits of a front brake light and makes the switch almost pointless.

I am using the same brake shoes (asbestos type) as back then 50 years ago. The results are/were exactly the same, better feel and effective control of the front brake. It is way better for light and medium braking. Now, as then, all normal braking is done with two finger pressure, with very controllable and smooth stopping.

I do think a front brake switch is a good idea and like yuor solution posted above and will look into implementing a similar solution on my brake lever.

Shippy. Where did you get the Doherty cable without the light switch? Or could you give me a part number so that the local britbike supplier can see if he can get me one?

Thanks for any help/info you can offer.

Cheers, Wilf

A 1967 brake cable for a T100R (or "C") wouldn't have a brake light switch. Same for the 650s.
Depending on the handlebar height, that cable would interchange with a '72 500 one.

Dunno, I’ve never had a problem locking up the front tire with the “mushy” OEM switch. Is that a common issue? It’s hard to imagine a manufacturer would sell a bike that had questionable braking due to the switch design. Yes, the early brakes were poor and were redesigned as the bikes got faster. After the switches were added I think the issue with poor brakes is more in brake fettling, not the switch. Just my $.02

I've now fitted a front brake switch Inspired by Stein Roger's front brake switch. It uses an aftermarket push-in switch, which is freely available and cheap.









It takes very little travel of the brake lever before the brake light goes on and in one stroke, eliminates all the issues of the in-line switch.

Works absolutely great! Thanks for the idea Roger.

Nice Shippy! Yours is neater than mine, looks really well. The switch is the same. Who'd have thought a cheap looking thing like that could work at all, let alone for years, but it does.
The deletion of the switch improves the feel at the lever, though in my case somewhat negated by the longer actuator arms. These aren't really required on a twin in my experience, but nice on a heavy Trident. These are 25 mm longer and makes braking effortless, if a little mushier.

SR

Stein Roger, Where did you source the acuator arms?

I have a clutch perch with the switch on my T150V. Wish I had its mate for the front brake.

Pete, I welded on the extension pieces myself, using SIF bronze on the longer pair and Castolin silver on the other.
Cheap rim paint finish works well for me...

SR

Nice work!!
That switch is a great improvement. Thanks for the photos.

What is that clutch lever switch used for? Maybe electric start circuit? Not familiar with the T150V here….

KC - look closer at the pictures, the switch is for the front brake to eliminate the in line cable switch.

Refering to earlier post pidjones "I have a clutch perch with the switch on my T150V. Wish I had its mate for the front brake." I think. I dunno what it means either!

I guess this sort of switch would work on the disc front brake lever. It's got to be better than the horrible nylon POS.
Probably looks better than the banjo bolt switch on my T120V or the hydraulic switch with the T fitting on my Trident.

I picked the perch and lever up at Barber last year. Liked the look and angle of it. Having the superfluous safety switch doesn't bother me. But, it would be great if the brake perch matched it, because I would use that! Don't understand the reasoning behind mounting the switch in the cable.

Hi,
Simplicity. Certainly the chromed steel levers were supplied by AMAL; in the late 1960's, don't think anyone would've considered mounting a microswitch on the lever?

I'm with @KC. When I got my T150 (with the better pre-'71 TLS), having spent over twenty years with twin front discs on T160's, I was concerned by The Legend Of The Mushy Brake Switch. However, given a heavy-duty cable mentioned by @desco, braking with the switch hasn't ever given me any cause for concern on the road (track days are a different matter, brake lasts about twenty minutes before it starts to fade noticeably, but that's another story) and a triple is a damn' sight heavier and faster than any standard twin.

A couple of years ago, a TriumphRat contributor took a switch apart and posted photos. of the bits. Not a lot in 'em; without taking apart my T150's switch to compare, suspicion probably points to the rubber washer - if BSA didn't spec. or q.c. the thickness and/or quality of the rubber (and Gk what today's pattern parts makers put in 'em) seems likely the source of "mushy" switches?

Hth.

Regards,

Some of us wouldn’t consider making holes in an area of an alloy brake lever, that is under tensile stress.