Mk3 Rear Brake Mounting.
- Thread starter GRM 450
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Hi Graeme, don't have a pic as yet, but fits like this
. .... Shocker... lower mounting fits into special bolt which is put in from the wheel side, this bolt has a "square" machined at it's head,(remember that bit!), the shock has then a washer which is slightly larger than the rubber bush fitted to stop the bush coming out during riding, this rests against the tube that goes through the bush, then a nut goes on after the washer , once tightened ,after mounting brake plate,(see below), think it's 25psf, make sure the body of the shock does not touch the side of the swinging arm mount, you may need to put in a washer between them to give you clearance, also make sure the shock body can move slightly on the bush. Now I KNOW it's NOT a Mk3 but if you go to The Colorado Norton site home page, look down and you'll see... 'Experience the 038 Cafe'... click 'read more' and up will come a set of pics, on the 3rd column, 3rd pic down there is a good picture of how the shock should fit with the washers as I said it's NOt a Mk3 but it gives a good idea on the fitment.
The Brake mount... fit a portion of the spindle through the swinging arm and put it through the brake plate hole, there is a channel about 2" long cut out the brakeplate, this goes over the aforementioned 'square' piece on the shock mounting nut , that is all there is to fitting the brake plate, obviously tighten everything up after setting chain adjustment.
If I've missed anything someone will pick it up, so you'll get sorted.
If you need pics I'll take a couple for you just let me know.
Robert
. .... Shocker... lower mounting fits into special bolt which is put in from the wheel side, this bolt has a "square" machined at it's head,(remember that bit!), the shock has then a washer which is slightly larger than the rubber bush fitted to stop the bush coming out during riding, this rests against the tube that goes through the bush, then a nut goes on after the washer , once tightened ,after mounting brake plate,(see below), think it's 25psf, make sure the body of the shock does not touch the side of the swinging arm mount, you may need to put in a washer between them to give you clearance, also make sure the shock body can move slightly on the bush. Now I KNOW it's NOT a Mk3 but if you go to The Colorado Norton site home page, look down and you'll see... 'Experience the 038 Cafe'... click 'read more' and up will come a set of pics, on the 3rd column, 3rd pic down there is a good picture of how the shock should fit with the washers as I said it's NOt a Mk3 but it gives a good idea on the fitment.
The Brake mount... fit a portion of the spindle through the swinging arm and put it through the brake plate hole, there is a channel about 2" long cut out the brakeplate, this goes over the aforementioned 'square' piece on the shock mounting nut , that is all there is to fitting the brake plate, obviously tighten everything up after setting chain adjustment.
If I've missed anything someone will pick it up, so you'll get sorted.
If you need pics I'll take a couple for you just let me know.
Robert
Thank you Gents,
The bolt with the flats on it, that goes through the caliper bracket, then through the shock is my concern.
The flat section isn't long enough to clear the caliper bracket, so if this bolt is done up tight it will crush the bracket against the swingarm.
Then, if the chain needs adjustment, the "shock" mounting bolt, as well as the axle would need to be loosened to move the wheel back or forward.
Is this how it's supposed to be ?????????
The bolt with the flats on it, that goes through the caliper bracket, then through the shock is my concern.
The flat section isn't long enough to clear the caliper bracket, so if this bolt is done up tight it will crush the bracket against the swingarm.
Then, if the chain needs adjustment, the "shock" mounting bolt, as well as the axle would need to be loosened to move the wheel back or forward.
Is this how it's supposed to be ?????????
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GRM 450 said:
Yes, apparently so, but even with the shock nut tight, it doesn't seem to stop the adjuster pulling the wheel back (unless possibly the shock nut was seriously overtightened?) although maybe it would be better to loosen the shock nut by half a turn before doing chain adjustment?
Thanks to all, I appreciate your efforts.
pelican, I've just done the other side with the speedo and the "half axle" has a flat on it also that locks it into the swingarm. (stops it turning when the axle is tightened)
The flat protrudes past the thickness of the swing arm and doesn't allow the nut and washer to do up tightly.
So I had to turn the flat section off a mm to stop it protuding past the swingarm.
This bike was put together by clowns, or reassembled by clown mechanics.
It doesn't seem right that someone actually rode this thing in the past.
I can't see how the wheel didn't wobble ?????
pelican, I've just done the other side with the speedo and the "half axle" has a flat on it also that locks it into the swingarm. (stops it turning when the axle is tightened)
The flat protrudes past the thickness of the swing arm and doesn't allow the nut and washer to do up tightly.
So I had to turn the flat section off a mm to stop it protuding past the swingarm.
This bike was put together by clowns, or reassembled by clown mechanics.
It doesn't seem right that someone actually rode this thing in the past.
I can't see how the wheel didn't wobble ?????
As far as I'm aware (well, on my Mk111 anyway) the washer under the nut on the stub axle should also be a thick one (1/8") as per the one visible on the disc side in Reggie's photos.
The thick washer with sufficient ID to clear the stub axle is what allows the larger diameter to protrude through the swing arm. The washer centres on the larger OD rather than the threaded section. This also ensures that the chain adjuster is equally supported on both sides. Having turned down the stub, there is now the possibility that the adjuster will distort instead of pulling square.
All of these bikes are now at least thirty years old and as has been mentioned here before, they're only as good as the previous owner. The old Haynes manual used to say something along the lines of "If the part doesn't loosen easily there's something wrong" and I think that this can also be applied to parts that don't fit. It's always worth looking at all the components and seeing if something else is wrong or missing.
The thick washer with sufficient ID to clear the stub axle is what allows the larger diameter to protrude through the swing arm. The washer centres on the larger OD rather than the threaded section. This also ensures that the chain adjuster is equally supported on both sides. Having turned down the stub, there is now the possibility that the adjuster will distort instead of pulling square.
All of these bikes are now at least thirty years old and as has been mentioned here before, they're only as good as the previous owner. The old Haynes manual used to say something along the lines of "If the part doesn't loosen easily there's something wrong" and I think that this can also be applied to parts that don't fit. It's always worth looking at all the components and seeing if something else is wrong or missing.
That makes sense to me 79 x 100, but the larger, flat sided section that protuded past the swingarm had a taper where it tapered down to the thread. It was only the taper that protruded, which is possibly why the chain adjuster was deformed on that side. It wouldn't have been able to pull evenly, and there was no 1/8" thick washer. The parts manual doesn't show a thick washer either.
Your description of how it's supposed to be makes sense, maybe the sprocket is thicker than the original that left the factory? and this prevents the thick flat bit protruding a little further for the chain tensioner, and the thick washer has been lost years ago?
The end result I have is the wheel spins freely with no side slack, the speedo has a very slight resistance to spinning with the wheel, and I have to loosen the right side bottom shock bolt to adjust the chain. And be careful to look after the left chain adjuster.
Comments ? does this sound correct for a Mk3 ?
Regards Graeme.
Your description of how it's supposed to be makes sense, maybe the sprocket is thicker than the original that left the factory? and this prevents the thick flat bit protruding a little further for the chain tensioner, and the thick washer has been lost years ago?
The end result I have is the wheel spins freely with no side slack, the speedo has a very slight resistance to spinning with the wheel, and I have to loosen the right side bottom shock bolt to adjust the chain. And be careful to look after the left chain adjuster.
Comments ? does this sound correct for a Mk3 ?
Regards Graeme.
The parts book is pretty awful in this area, not least because it shows a stud instead of an axle with a hex. head.
My parts book doesn't show any of the fixings for the drive side but part no. 27, the 06-5984 washer shown on the timing side is listed as qty. 2 so it would seeem correct that there should be one at each end.
I have always found it completely normal to slacken the lower damper stud nut before adjusting the chain. The angle has to alter as the wheel moves.
I'm not sure about resistance in the speedo drive. Is it freshly filled with grease ? If it's worn on the worms then it will fight against itself a bit.
My parts book doesn't show any of the fixings for the drive side but part no. 27, the 06-5984 washer shown on the timing side is listed as qty. 2 so it would seeem correct that there should be one at each end.
I have always found it completely normal to slacken the lower damper stud nut before adjusting the chain. The angle has to alter as the wheel moves.
I'm not sure about resistance in the speedo drive. Is it freshly filled with grease ? If it's worn on the worms then it will fight against itself a bit.
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79x100 said:
Yes,the assembly as drawn in the parts book isn't entirely correct, as the axle is shown with no hexagon, its washer is missing, the dummy axle nut and washer aren't shown in the correct place, and the oil seal [25] is drawn on the wrong side of the bearing [23].
The assembly as drawn in the 850 MkIII workshop manual is correct as far as I know, although on my own MkIII, I have to fit the washer [32] between the bearing [23] and the spacer [11] to stop the drive gearbox rubbing against the sprocket boss.
I'm not sure what I've got in there LAB. After all these years, there are some things that I just take for granted and the sprocket is not something that has to be removed very often. I certainly have a thin large OD washer outside of the the speedo drive.
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