Author Topic: Typical front drum brake light switch - info needed (Read 6345 times)

Tim. · « **on:** August 19, 2007, 09:23:47 PM »

So, I'm back on the front drum as my brake of choice for my project, and need to sort out the brake light switch. I think the original had some mechanism built into the lever - is this the norm?

I need something, ideally that can work with aftermarket levers

mark · « **Reply #1 on:** August 20, 2007, 01:53:08 AM »

Hmm... very interesting.

Brake lights on early bikes with front drum - not always what we would call 'the norm' by modern standards.

A look at the old CB450 book turned up a couple of possibilities........

(a)Earliest models - no switch - no front brake light - step on some rear brake to get brake light.

(b)Early models - switch built into brake cable.

Late model - disc with hyd. switch like the fours.

Seems like Suzuki went with (a) as well.

Other makes - I dunno?

Happy trails.

kghost · « **Reply #2 on:** August 20, 2007, 09:02:08 AM »

Why not rig a switch such as the rear switch off a 750 to the front?

Tim. · « **Reply #3 on:** August 20, 2007, 04:56:08 PM »

I can't think of a way to make that (rear brake switch setup) look nice frankly.

So I stopped in at my local wreckers and while I didn't find a drum brake lever with a switch, I did find a few clutch levers with switches - the safety switches.

Tested continuity, and confirmed the circuit closes when the plunger is out - i.e. when the lever is not pulled, the circuit is cut, which is perfect.

Found one that looks like it will mount flush to the bottom of my Tommaselli style levers. A 6mm allen-head bolt threaded into the lever should press on the plunger.

But, I'm considering a different approach. There is enough meat in the lever perches to drill a hole and mount one internally, like the safety switches found on our Honda SOHC clutches. This would make for a much neater, easier and more reliable solution. Better all-round.

Just need to find one of those, so if anyone has one laying around, let me know. First and foremost I need to confirm dimensions, but I'm sure it can be done. Just need to have the hole drilled through accurately. Need to confirm the switch is the same design too - i.e. circuit will activate when the lever is pulled, not the other way 'round.

Raul CB750K1 · « **Reply #4 on:** August 21, 2007, 12:10:34 AM »

The switch is still available from Honda. I bought one for my CB350 and it was something like 9 euro.

BUT, I've seen aftermarket levers and they have provision for both clutch and brake switch -that you have to buy separately-. Search a little harder and you will find them.

Raul

Tim. · « **Reply #5 on:** August 21, 2007, 04:21:20 AM »

I bought one of the switches too, for my 550F. Don't have it anymore though. I need to confirm size and operation before I order the switch from Honda.

The levers I have are the ones I want to use, so I'll likely modify them to work. Haven't seen any aftermarket levers that would have the provision for a switch yet.

Raul CB750K1 · « **Reply #6 on:** August 21, 2007, 04:30:45 AM »

http://louis9.louis.de/katalog2007/pages/649.pdf

Go to the bottom of the page and see the aluminium and black levers. The key is the sentence "passender Bremslichtschalter", that is, "brake light switch". Unfortunately, shipping costs from Germany would easily exceed the parts price.... $:-\$

dusterdude · « **Reply #7 on:** August 21, 2007, 01:54:44 PM »

you arent going to find anything that looks worth a toot.

bryanj · « **Reply #8 on:** August 22, 2007, 06:13:18 AM »

TinTin one of the gold wings had a brakelight switch that bolted underneath and was activated by a "lump" on the lever. would that type help?

Tim. · « **Reply #9 on:** August 22, 2007, 09:53:50 AM »

Yep - that's one possible solution that I was exploring with the use of a clutch safety switch I found at a wreckers. Finding a right-side switch would be best, as flipping the switch over from the left to right poses some issues.

crazypj · « **Reply #10 on:** August 22, 2007, 12:34:19 PM »

Suzuki uses a micro switch bolted under the lever perch. Yamaha and Honda used a front brake perch with a hole through for switch. modifying Tommaselli lever you could probably find a micro switch to bolt under it with a tab for operation
PJ

tsflstb · « **Reply #11 on:** August 22, 2007, 01:23:37 PM »

That's what I was thinking. Mikesxs.com has these for $5.00. I've got one of his master cylinders with this setup and it works fine. Might be worth trying to mount it under your brake perch.

Tim. · « **Reply #12 on:** August 22, 2007, 01:32:37 PM »

Wow - didn't see those at Mikesxs. I'm likely going to drill a hole and use one of the torpedo-shaped plunger switches. It will ultimately be the easiest and look the best. Just need to find the smallest one possible so I don't have too big a hole to drill.

chrisf · « **Reply #13 on:** August 23, 2007, 11:46:35 AM »

TinTin:

I just bought what you described from the Honda dealer. It was $13 and maybe 5/16" at most. I can pull my old one if you really want to know the diameter. The one I ordered was for a 71 CB350.

--HTH, Chris

Tim. · « **Reply #14 on:** August 23, 2007, 01:09:03 PM »

Chris - I'd love to know the diameter. On your bike, is this all built into the control pods? I might consider buying a set of switches for the CB350 to kill all the birds with one stone.

Importantly, I need to know how the switch works - i.e. do you have continuity when the plunger is in or out?

chrisf · « **Reply #15 on:** August 23, 2007, 03:39:36 PM »

OK, don't go to the machinist with this info, but it should help you along. The diamer is 8mm. The piece I have is damaged; hence the need to buy a new one. On the piece I have, it is 11mm long. The button/switch part is 5mm.

I don't know if it uses switched ground or switched live. I'm wiring it for switched live. When the button is depressed, the circuit is open--i.e., when the handlebar is at rest and pushed the button in. The ciruit closes when the button is released.

--Chris

Tim. · « **Reply #16 on:** August 23, 2007, 10:26:00 PM »

Sounds like it will work out perfectly - I'll order one from Honda tomorrow. I seem to recall paying $13 for the last one I bought a while back (550F). If it completes the circuit when the lever is pulled, then I'm golden - will plug right into the brake light circuit and light the rear light up for me.

Just need to check if I can safely drill an 8mm hole through the perch without weakening it too much.

Tim. · « **Reply #17 on:** August 25, 2007, 07:04:59 PM »

New solution I'm exploring - turns out there are a few bikes out there where the front drum brake cable has a switch integrated into it with leads coming off to connect to the harness.

Is there any reason to think a cable from a lighter bike, say a 400 or smaller, would be lighter gauge than the brake cable for the 650? Don't want the cable breaking on me

bryanj · « **Reply #18 on:** August 29, 2007, 04:22:42 AM »

TinTin 1969 ish Triumph 650 had a brake light switch in the cable

Tim. · « **Reply #19 on:** August 29, 2007, 06:41:16 AM »

Yeah, I've looked at some of the british cables, but they have this odd connector on the cable to plug into the harness - the Japanese cables have longer leads off the cable with typical bullet connectors which will make it easier to connect. Lots of Japanese models to choose from - just need to confirm the length of housing/cable.

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Author Topic: Typical front drum brake light switch - info needed (Read 6345 times)

chrisf

chrisf