Hello all, Please excuse my "butchery" but I managed to simply remove the splined bush off the crankshaft by turning an aluminium dolly to fit inside and then gently heating up the bush with a plumbers blowtorch and then hitting dolly to remove. Looked online and there's all sorts of special tools but this work a treat.

8 hours ago, ColinPybus said:

Hello all, Please excuse my "butchery" but I managed to simply remove the splined bush off the crankshaft by turning an aluminium dolly to fit inside and then gently heating up the bush with a plumbers blowtorch and then hitting dolly to remove. Looked online and there's all sorts of special tools but this work a treat.

Excellent! Can you explain how this process works?

This bush needs to be removed to get the crankshaft and flywheel from the engine casing. As it's pressed on at the factory you can get/make special tools to draw it off. As it's a shrink fit on the shaft a bit of heat on the splined bush helps it expand and then my turned aluminium dolly is placed at the end of the crank and then hit " gently" with a hammer. Upon reassembly I will place crank in the freezer overnight ( in a plastic bag of course ,this will help fitting of the bearings as well) to shrink diameter and then again use plumbers blow torch to heat up bush to make it expand. It should slip easily over and then once cooled it should be a tight fit again.I will take photos tomorrow of it all loosely assembled. Hope this helps. I am finding the refurb of this bike horrendously expensive!! To this end I am making it my bike and not straight out of the factory. I've cylindrically ground the swing arm shaft and turned new bushes to suit . I've turned new brake lever bushes as well. I intend to try and spark erode a generic gear lever with the gear lever shaft as an electrode. I am also  going to make a new rear brake arm that will be rod operated as opposed to a cable. I know  all these bits can be purchased new but I could spend £5k on a bike that's worth £2.5k . Hope Mick Andrews doesn't mind!!

5 hours ago, ColinPybus said:

This bush needs to be removed to get the crankshaft and flywheel from the engine casing. As it's pressed on at the factory you can get/make special tools to draw it off. As it's a shrink fit on the shaft a bit of heat on the splined bush helps it expand and then my turned aluminium dolly is placed at the end of the crank and then hit " gently" with a hammer. Upon reassembly I will place crank in the freezer overnight ( in a plastic bag of course ,this will help fitting of the bearings as well) to shrink diameter and then again use plumbers blow torch to heat up bush to make it expand. It should slip easily over and then once cooled it should be a tight fit again.I will take photos tomorrow of it all loosely assembled. Hope this helps. I am finding the refurb of this bike horrendously expensive!! To this end I am making it my bike and not straight out of the factory. I've cylindrically ground the swing arm shaft and turned new bushes to suit . I've turned new brake lever bushes as well. I intend to try and spark erode a generic gear lever with the gear lever shaft as an electrode. I am also  going to make a new rear brake arm that will be rod operated as opposed to a cable. I know  all these bits can be purchased new but I could spend £5k on a bike that's worth £2.5k . Hope Mick Andrews doesn't mind!!

Sounds great. I'm all for your improvements. I was confused because I had thought that collar/bush was mounted on a taper rather than being an interference fit

This bush needs to be removed to get the crankshaft and flywheel from the engine casing. As it's pressed on at the factory you can get/make special tools to draw it off. As it's a shrink fit on the shaft a bit of heat on the splined bush helps it expand and then my turned aluminium dolly is placed at the end of the crank and then hit " gently" with a hammer. Upon reassembly I will place crank in the freezer overnight ( in a plastic bag of course ,this will help fitting of the bearings as well) to shrink diameter and then again use plumbers blow torch to heat up bush to make it expand. It should slip easily over and then once cooled it should be a tight fit again.I will take photos tomorrow of it all loosely assembled. Hope this helps. I am finding the refurb of this bike horrendously expensive!! To this end I am making it my bike and not straight out of the factory. I've cylindrically ground the swing arm shaft and turned new bushes to suit . I've turned new brake lever bushes as well. I intend to try and spark erode a generic gear lever with the gear lever shaft as an electrode. I am also  going to make a new rear brake arm that will be rod operated as opposed to a cable. I know  all these bits can be purchased new but I could spend £5k on a bike that's worth £2.5k . Hope Mick Andrews doesn't mind!!

Please show us how you get on with replacing the rear brake cable with a rod.

I hope to do something similar with my own MAR, but haven't come up with ( or seen elsewhere) a simple & neat way of doing it.

( I have left hand gear lever , right hand brake on mine, which I want to retain. Right hand gear lever, left hand brake would probably be easier  to modify)

Hello there, I will post some pics later on about my plans for a rear brake rod. Today however I managed to spark erode the splines on a generic gear lever using the gear change lever as an electrode. It went a lot better than I thought it might . Unfortunately I can't get video of spark erosion to work on this site.

Hello again, First stage of rear brake rod mod was to file , fit and machine this old part I had laid around. I will then fit a rod end bearing to the upstanding diameter . I will drill and tap the upstand and secure rod end bearing with a cap screw and washer.I have mocked up a cardboard brake arm with a scrap brake rod I have to give you some idea . If brake arm is long enough it will clear the existing cable stay. I will copy an existing rod operated brake set up to secure rod to brake arm. Again I will use brake cam spindle to spark erode splines in aluminium plate I will use to make brake arm. I hope this helps.

The saga continues, the bracket I'm using on the brake pedal shaft wouldn't drill as it was too hard, as I was going to bolt rose joint to it, so back to the spark eroder and I tubed a hole through and then fixed with a bolt and nyloc nut. I drilled and tapped  the threaded end of the rose joint M5 and and fitted a threaded end 5mm diameter rod to it with an lock nut. In hindsight I should have used a female rose joint, it would have looked better. Alloy brake arm to make now and cut rod to correct length!

Interesting, can't wait to see this finished.

If I remember correctly, the brake shaft is just  beneath the swingarm end , with not much space , so will be great to see how this fits & operates  

One year later and I've just fitted my rear brake rod ( 5mm diameter) to the rose joint off the brake pedal and to a new rear drum brake arm I've made. All ok but rod flexes ( bends) when in use , not ideal. To this end I've ordered some 8mm diameter thick wall tubing which I hope will do the job. Hopefully I'll put some pics on the site once I'm done. 

P.S. I found out too late you cannot fit the brake pedal once the engines in. I had to grind of the left hand side to get it to fit and then fitted a longer oilite bush and sleeve to make up the lack of length.

Hello, could you please post a photo or sketch of how this rear brake rod is set-up & works, as I had a look at doing something similar on my own Ossa , but there didn't seem to be room for a rod

( caused by the brake pedal shaft being in a tight space under the swing arm)

I would be interested to see how you got round this problem, or have I missed something obvious that would have worked.

I did think of a brake rod that worked in compression rather than in tension, but this is never an ideal way to do things , and would require a strong/heavy rod to avoid bending.

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Please see previous posts on rear brake mod. There's plenty of room for the rod, however I'm removing this and replacing with 8mm thick walled tubing for better strength. Rear brake arm lever still needs a bit more tinkering . Still struggling to attach photos, they always seem to be too big to attach. Can't remember how I've done it before.

Hello, thanks for coming back about this.

so, looking at the pictures, you have left hand gear lever , right hand brake lever.

Am I right in seeing that the lever/pivot with the rod end fitted , is on the underside of the crossover shaft when fitted to the frame ?

So when you press the brake pedal the lever will push the brake rod backwards ?

And therefore push the lever on the brake plate backwards as well ?

Which is the opposite way to how the original system works ?

(But would still operate the brake, but with the rod in compression, rather than the usual way of the rod in tension when in use)

Have I got that right , or completely wrong ?

  have I misunderstood how it works .