Topic: Rear brake light issue

[rocknroll_kb]

Hello... I have a 750K4 chopper that was actually built in the 70's.  I am having a problem with my rear brake light working.  The switch is oem honda, the light is not, and it looks that the rear brake setup and hub are honda laced to a 16" harley wheel.  My problem is that if I adjust the switch to work when the bike it sitting still, the light doesn't work while I'm riding.  If I adjust it to work while I am riding, then the light comes on for no reason when it is sitting still.  Sometimes when I have been riding a long ways and I hit the brake, there is about 1" of free travel, then a "clunk."  After the clunk, the brake seems to be working fine.  Any ideas?

[bryanj]

For the clunk check the torque arm, for the light switch no sensible answer unless the suspension is moving a helluve lot

[scunny]

worn brake pads and dodgey wiring

[rocknroll_kb]

bryanj -- this is a rigid chopper, has no rear suspension.

scunny -- new brake pads, and I completely rewired the bike when I first got it.  All new switches, wiring, etc.  I have been a diesel mechanic and hot rod / motorcycle enthuisiast for 15+ years, I know it is wired up correctly.

[HITMAN]

The brake light switch itsself might be your problem, especially if they are off-angle.  If they dont have a 'straight on' pull the drag sometimes makes them sticky.  Just a thought?

[bryanj]

Yes the spring needs to pull straight, Also I have seen a worn switch go Off,On,Off as the spring is pulled. All the Hondas use the same switch, i buy them by the dozen!

[rocknroll_kb]

Thanks...  the switch was slightly off-center, after correction, it seems to work better.  I am in the process of fabbing up some forward controls for the chop, so the switch will have to be relocated in the near future anyways.  Since riding is pretty much over for the winter, I am going to pull the rear wheel assembly back down and inspect everything again to see if I can find my "clunk."  How hard is it to convert the rear to a supersport style disc brake?  Are the discs hydraulic? I imagine they would have to be.  I have no front brake on the bike, and don't plan to install one, so I need a reliable brake on the rear.  The drum seems to be very reliable other than the clunk...  but the disc looks better in my opinion, and seems like it would be easier to service (pads, etc.).

[Bodi]

The clunk is likely a sloppy torque arm. The holes in the arm can become oval and allow a bit of brake plate rotation. Pull the bike back and stop it with the rear brake, then roll forward and stop - you should be able to see or feel where the motion comes from. This shouldn't be a safety problem unless it gets extreme, one thing is that the brake plate rotation will pull against the operating lever and increase the brake pressure: when the arm gets really sloppy this can cause rear brake lockup if you use the brake suddenly after backing up and braking (which sets the plate at the opposite end of the slop)...

[cleveland]

It's a bit off the topic, but can we see the bike?  Got pics? 

[rocknroll_kb]

I don't have any good pics of it after most of the work I have done to it...  The first pic is of the bike how I bought it.  The rest of the pics are stuff I have changed, including a solo seat, dyna ignition (electronic plate & coils).  I have done a lot more to it since, but don't have any pics...  It is dissassembled right now (tank and fender off, carbs off, rear wheel off).  When I get it back together I will post some better pics.  The seat and ignition pics were taken at night...  all pics with a camera phone      I have completely rewired the bike, upgraded to Dyna S ignition, replaced all switches, relaced front wheel (21"), installed solo seat and springs, rebuilt and rejetted carbs, bobbed 4" off of rear fender, replaced tank with larger "king" sporty tank.  I am working on some forward controls right now.  I plan to get everything mocked up and ready to ride for the summer (short winters here in SC), and ride it all summer, then I'll tear down for paint next winter.  I am thinking of going with some drag bars maybe, but am afraid it will make the beast even harder to tame at slow speed turns.  Any ideas or sugestions are greatly appreciated.

[cleveland]

Sweet!  I can't wait to see it when it's done.  Those old school choppers take me back. 

I have seen the drag bars on choppers, but never without raisers. 

[dpen]

I disconnect the rear brake light so I can slow down if any cars with flashing lights appear behind me

[dusterdude]

the best way to go disc,is to buy a harley wheel with hub setup and buy harley disc brake parts to go with the year wheel you buy.

[rocknroll_kb]

That's probably the route I'll take...  I have owned several sportster-based choppers and am more familiar with the harley brake setup.  The rear wheel appears to be harley, so I can just find a hub to lace it to and the brake components...  As far as the disconnected rear brake switch, I have no front brakes( and thus no switch), and have been rear ended before (the end of my beloved ironhead sporty chop, plus a broken leg and 32 stitches to close the hole where the bone decided to pop out), so I'll keep mine hooked up for now...