Hi I'm wondering if any has modified the rear brake on a Ossa Mar to remove the cable and convert into a direct link pull.

If so how is this done and does it improve the rear brake action at all. Many thanks

 

I have seen photos only, never rode it.  In simple terms, a giant "C" shaped brake arm was installed to replace the short cable housing pusher arm.  A rod ran from the top of the "C" to the rear wheel.

Wanted to add, I think the guy in NZ is looking for a later OSSA rear wheel setup, suspect he plans to run a rt side brake setup.  

Also, saw photos of different rear wheels fitted to the OSSA MAR, allowing all RT side brakes.

The best thing you can do for a MAR rear brake is fit a decompressor

 Back in the day of the MAR we ran no idle. The engine had so much mass (along with the Bul and the Cota.) that it slowed it down enough the brakes almost worked. That style of riding works pretty good with more modern sections. With an idle it just runs to quick.

A MAR with brakes?  Somewhat of a novel concept that.  I seem to recall the main purpose of the linings on the Ossa was to remove rust on the surface of the drum ☺

With modern shoe linings machined to fit, the MAR brakes work fine. There's nothing wrong with the cable arrangement, as tortuous and contrived as it is, it works fine as a mechanism for operating the brake arm - but only if the linings are good. A rod operated brake is still no good on any bike with duff linings so replacing the MAR cable with a rod will achieve nothing.

Using a decompressor or just using the engine braking with no idle is fine in dry / grippy conditions but useless in slippery conditions or mud as the rear wheel will just lock and stall the engine.

The biggest problem with the rear brake is the weak casting of the brake plate. If the brake snaps on too hard it can break the casting on the brake plate slot that sits on the lug on the swingarm (it usually takes the cable locator with it...)  If that happens there is no way of holding the brake plate in place and it just rotates when the brake is applied. This is usually because the slot wears over time and can chatter on the lug. If there is any play between the slot and the lug it's best to pack it and remove any chatter. This will at least reduce the chances of snapping it.

On 13/05/2017 at 10:39 PM, pmk said:

Thank all. I have a decompressor on there already and it is most useful in the dry. I find with the cable (vernhill) it is too long to adjust properly. I have new shoe's in there. Ispent last trying to bed them in using chalk and sand paper and they feel better. I did turn the idle down at Sunday's trail and that made a big difference. That big flywheel just pushes you forward on tick over if set to high. 

I was think of a C shaped lever a suggested but will take abit of head scratching to work that out if I go that way.

Thank you all for your input.

 

I've never had a problem adjusting the cable on the MAR ?

Brand shoes are pretty crap compared to having them re-lined with modern material. Villiers Services, Safetec and others can re-line your shoes with a much better material that actually works. Mine works fine with the cable, front and back. A lot easier than trying to concoct a rod and which ultimately, will still be operating less effective brand shoes

On 5/14/2017 at 10:05 AM, lineaway said:

 Back in the day of the MAR we ran no idle. The engine had so much mass (along with the Bul and the Cota.) that it slowed it down enough the brakes almost worked. That style of riding works pretty good with more modern sections. With an idle it just runs to quick.

OSSA MAR motor is fabulous with a dead throttle ("idle" set so the motor eventually stops if you leave the throttle alone with clutch in)

On 13/05/2017 at 10:39 PM, pmk said:

Thank all. I have a decompressor on there already and it is most useful in the dry. I find with the cable (vernhill) it is too long to adjust properly. I have new shoe's in there. Ispent last trying to bed them in using chalk and sand paper and they feel better. I did turn the idle down at Sunday's trail and that made a big difference. That big flywheel just pushes you forward on tick over if set to high. 

I was think of a C shaped lever a suggested but will take abit of head scratching to work that out if I go that way.

Thank you all for your input.

 

 

Edited October 15, 20178 yr by nivlac123
Missed post

It looks like I have the cable for the wrong model. There is no threaded bar on the hub end. Im bike is mk1 but have mk2 swingarm 

On 16/05/2017 at 10:01 PM, woody said:

I've never had a problem adjusting the cable on the MAR ?

Brand shoes are pretty crap compared to having them re-lined with modern material. Villiers Services, Safetec and others can re-line your shoes with a much better material that actually works. Mine works fine with the cable, front and back. A lot easier than trying to concoct a rod and which ultimately, will still be operating less effective brand shoes

Ever feel like your talking to yourself ?

OK I have verified that my swing arm is still a mk 1. Would anyone know which cable I would need. I have the one with the nipples on both ends and adjuster in the middle. Would I need the one with the threaded rod at the end.

 

Edited October 19, 20178 yr by nivlac123

when I was looking for a replacement rear brake  cable for the worn one on my MAR , all the replacement ones that I saw seemed to be made from thinner cable than the old one - they were the same thickness as the Universal Brake/Clutch cable kits that are available, but just not as thick a cable as the old one.

anyway , I purchased and fitted one of these cables and it worked okay, but did seem to stretch/flex a bit in use.

I wasn't really happy with it and ended up getting a Ford Transit Clutch cable with the threaded rod on one end and modified this to fit.

the Transit cable I used is the same thickness as the old cable that was on the bike, and it does seem better at  braking and resisting stretching / flexing now

as has been said - good linings + a good cable + proper adjustment and the standard setup can work well , despite looking like it shouldn't work !