Ideas for 'Rear drum brake rod' with mids. XS650

[ebb0tk]

Hi, im getting ready for my first (out of 2) inspection of this build.
Here in Sweden they dont like the long brake rods, because they flex when brake is applied.
Specially if they are bent, because they have a tendancy they wanna straighten out.

I need to find another ideas/solutions for this, any ideas are great. Im running jumpstreet mids.

Post whatever you can think may work or what you've done. Anything =)

Thanks, Tobias.

 

[gggGary]

A pivot, rockershaft at the crossmember should do it. Hugh's handbuilt makes a standoff, bushing to support the factory brake pedal shaft that should give an idea of how to build one.

http://www.hughshandbuilt.com/product/xs650-brake-pivot-kit/
Instead of the pedal attach a second arm to the forward pull rod. By varying the angle between the two arms on the shaft this will transfer the force inward and correct any difference in angles between the two shafts. The shaft/support need to be a machined fit with bush, bearing or provision to lube it.
Good practice would be to have one of the arms removable so it can be disassembled inspected and relubed. You are using the brake shoe pivot arm, cam backwards, I think that is OK but take a good look at the cam profile inside the drum, you may need to grind/smooth the profile a bit to use it "going the other way".

 

[ebb0tk]

The pivot arm is none XS650, i think its from an XV 750 or 920, so its straight and good fit.
Yeah that might work, i was on the route going cable wise on the rear aswell. I found out that an front brake pivot arm from an XT500 fits the rear XS650.
But this will be non bolt on aswell, but think it will look cleaner with a cable rear.

 

[gggGary]

I get that you have a very clean looking build going Others have reported issues using a rear cable (weak, too stretchy). I think a cable would work but it would need to be considerably heavier gauge than a typical Japanese front brake cable, the leverages, forces are different in the rear, a foot generates more force and is less sensitive than a hand. Something along the lines of the large diameter Harley type cables may do the job. If I ever do this type of bike my inclination is go disk and hydraulic just for the "clean look" aspect. there are some very nice rear MCs that can be neatly installed at the brake pedal.
FWIW that front brake looks a bit marginal for modern highway speeds. tho much better than NO front brake...........

 

[ebb0tk]

Ah okok =) Well yeah, i didnt want a disc up front so i ended up with a xt500 front wheel.
I'll have to scratch my head maybe, 2 and 3 times until i figure this rear setup.

 

[retiredgentleman]

Be thankful the inspectors in Sweden are good at their job. That bent activating rod is most unsafe. The front drum also on the weak side. Mechanically operated brakes ceased being used on cars about 80 years ago. They were replaced with hydraulic brakes for a reason....................they are much more powerful and safe.

I recommend you put disc brakes on the front and on the rear. If not that, at least put a disc brake on the front where most of the braking gets done. If an inspector sees a good disc brake on the front, he/she might be a little more forgiving as they inspect the rear.

 

[ebb0tk]

Im looking at this from: https://catalog.zodiac.nl/en/catalo...ontrol-cables/rear-brake-cable-for-harley-xl/

Maybe it would be adaptable..

 

[gggGary]

Im looking at this from: https://catalog.zodiac.nl/en/catalo...ontrol-cables/rear-brake-cable-for-harley-xl/

Maybe it would be adaptable..

Yeah that looks good (if it's long enough) maybe a custom length of that from motion pro?

 

[ebb0tk]

Yeah i had forgot about those guys, maybe then can sort something out for me. Will "stops" for the cable work welded to the frame, or do you think i need a stop on the drum? i mean so the cable can be adjusted. like attached pic.

 

[gggGary]

Stops could be drum or frame much easier on frame.

 

[ebb0tk]

Yeah, its my first build as you probably can tell. But better ask then being sorry atleast too many times =)
Thanks alot for help!!

 

[ebb0tk]

http://cbradleymotorsport.co.uk/brakes/handbrakes/rally-car-handbrake-cable.html

This does look good aswell.
Eye on one side to suit the brake pivot arm and the fork at the other end to suit the mid control.

 

[gggGary]

Drum from an old TX750

But you can see the cam profile is intended to operate only one way on this one!
I'd want to know the inner cable OD on that rally parking brake unit.

 

[ebb0tk]

Yeah i see, ill have a look on the one i got now. But what i remember it could be operated both ways.

Guess this cable found will be a few hours surfing on the web =)

 

[gggGary]

Don't even have to open it the difference in pull forward vs. aft is very noticeable, probably make it "touchy" also. If I get a chance I'll look in some other yammy drums also. Keep posting with what you find/do?

 

[ebb0tk]

Yes i will =) thanks

 

[gggGary]

well the xs650 drum cam is the same but hte cam from what I think was a later virago 535 was symmetrical!

 

[TwoManyXS1Bs]

Your rear brake stay is incorrectly setup.

An engineer would not allow that.
The stay rod needs to be in tension.
Forum search on "brake stay" for more info...

 

[ebb0tk]

Yep i know, attached pic is how its setup.

 

[retiredgentleman]

Yeah 2M, I agree the brake stay, in the red circle, is at a bad angle. It appears to be neither compression or tension, more like shear! His last picture shows it to be in compression, and that is fine. Some lads put the brake stay down under the axle, so the stay is in tension, and that is OK too.