change a cable rear brake to a rod?

[Kane Mcguire]

i always feel a cable rear brake is too spongey compared to a rod. im changing my xr 500 over to a rod. does alloy stretch or should i stick with steel ? anyones thoughts? or what they have done before. thanks

[frostype400]

Sounds silly to me the xr500 has a tls front brake that works sweet the rear I'd be more looking to hydraulic setup before a rod one.

[DR]

stick with a steel rod K. Due to the flex an alloy rod will fatigue rather quickly and could let go at the most inopportune time. A small issue may arrise with brake pedal rise and fall with suspension movement but from memory the XR brake hub stay is on the swingarm  so this like a floating brake would eliminate brake plate/pedal movement. I like the rod setup also for the positive feel they give and can see no reason why it wouldn't work as good or better than the cable setup.

[GMC]

Keep the cable.
If it feels spongy get a new cable as the outer cable deteriorates over time.

The rod system is disadvantaged by the swingarm action.
The floating rear brake is when the backing plate is attached to the frame via a torque arm.
When the backing plate is attached to the swingarm it rotates with the arc of the swingarm and so the length of the brake rod is changed.
When the backing plate is attached to the frame with a torque arm it maintains position as the torque arm and swingarm move in parallel.
You will need to have the junction of the rod and brake pedal as close as possible to the swingarm pivot to keep an even tension on the rod to avoid a spongy brake during suspension movement.

Cable and hydraulic systems don’t suffer this problem of tension on the brake pedal changing through suspension movement.

As your system was designed for a cable I doubt that the position where you would be joining the rod to the brake pedal would be in the ideal position of being over the end of the swingarm pivot.




Don’t know about this fad of changing old bikes to hydraulics.
Your changing the fabric of the old bike universe.
The original systems would work fine if they are up to spec.
If you can’t keep the old systems up to spec then I think you would have trouble setting up the complexities of modifying something to hydraulics.

[Viper666]

I agree, stick to cable if you can get a new one.

Is it secured by a rod to the frame or at the swingarm?

The perfect floating rear brake is the rod to the frame and a cable.

Stops compaction of the shocker under brakes. (Remember the floating "Anti dive" front brake mods they did in the 70's?)

Even modern bikes do it with their disc retained at the swingarm.

[Kane Mcguire]

thanks guys. good to get opinions first. decided to go disc. got a later model cr set up. have to cut the cr swingarm to pieces as its dimensions are way off.  it will work out good as i already have a cr front end.

[DR]

Small update on an old topic sorry,

A rod 'can' be used on long travel bike without a floating hub setup. In other words the brake hub fixed to the swingarm via a torque arm or the hub locating lug on the swingarm. Simple method.

Where the rod attaches to the brake pedal needs to be inline or very close to the swingarm pivot as mentioned by GMC above If this is done then there is no movement/pedal float in the pedal even at full bump. This is the method I used on my RM400C for many years when I fitted a cush drive DR500 wheel.  I've just noticed the '82-'85 RM80 is the same from the factory and this brought the memory of how I did it flooding back. Even though it is an 80 it has just as much or more rear wheel travel and the brakes work brilliantly.