Why is my MKIII front disk brake on the right side?

Hi everyone and thanks for allowing me to join! Just started working on my "new" late '77 MKIII roadster and I've noticed that the front break is on the "wrong" side. Shouldn't it be on the left side?

Supposedly to stop the bike pulling to the left I think was the factory reason

Ivodispili said:

Hi everyone and thanks for allowing me to join! Just started working on my "new" late '77 MKIII roadster and I've noticed that the front break is on the "wrong" side. Shouldn't it be on the left side?

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Yes, the Mk3 front brake would normally be on the left-hand side so if on the "wrong" side it has been moved to the right which is basically a matter of swapping the fork legs over although the Mk3 brake fittings are for a left-hand side brake.

baz said:

Supposedly to stop the bike pulling to the left I think was the factory reason

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The Mk3 brake was supposedly moved to the left-hand side for that reason.

Ditto the above, but I really think it looks out of place up there, fwd of the fork leg. I've considered swapping it over on my '75 Mklll on more than one occasion.

cjandme said:

Ditto the above, but I really think it looks out of place up there, fwd of the fork leg. I've considered swapping it over on my '75 Mklll on more than one occasion.

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If you turn the forks around you really need to use the pre mk 3 wheel
For reasons LAB has highlighted

baz said:

If you turn the forks around you really need to use the pre mk 3 wheel
For reasons LAB has highlighted

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The Mk3 wheel (hub) can be safely fitted either way around as it has a circlip bearing retainer, not a threaded lock ring.

Thanks guys, one of the reasons I haven't done that yet is that I've been a bit lazy when it comes to my bike. That's hopefully about to change this summer. I do however like the way the factory used a combination of hard lines and hoses to get a clean routing thru the yokes and down to the caliper.

L.A.B. said:

The Mk3 wheel (hub) can be safely fitted either way around as it has a circlip bearing retainer, not a threaded lock ring.

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Thanks for clearing that up, I couldn't remember the difference in the wheels
And didn't want anyone doing anything dangerous

Ivodispili, you need to make sure it is a MKIII wheel hub (circlip bearing retainer) before swapping it back to the correct side. Maybe the wheel was replaced for whatever reason in the past with an earlier one.

Thank Cliffa, I will check the hub but I think that I will keep it as it is now that I Have read all the answerS to my question.

I have always placed the caliper so it is behind the fork leg on my bikes, so that its mass is closer to centered on the steering stem, thus lessening the lever arm acting on it and magnifying its force on the steering. Moving it to the rear of the fork let makes the bike handle and steer better with less deflection at the bars--the same reason essentially all modern motorcycles put the caliper(s) behind the fork leg. Depending on the bike, that might be on the left, or the right side. On my 73 850 Commando, that ended up with my 12 inch disc and Lockheed caliper on the right side, with braided stainless line made to match.

linker48x said:

I have always placed the caliper so it is behind the fork leg on my bikes, so that its mass is closer to centered on the steering stem, thus lessening the lever arm acting on it and magnifying its force on the steering. Moving it to the rear of the fork let makes the bike handle and steer better with less deflection at the bars--the same reason essentially all modern motorcycles put the caliper(s) behind the fork leg. Depending on the bike, that might be on the left, or the right side. On my 73 850 Commando, that ended up with my 12 inch disc and Lockheed caliper on the right side, with braided stainless line made to match.

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I had read quite earlier in the 60's that mounting the caliper in the lower rear position to the disk was preferred. I had heard that MKIII front caliper was moved to left side to counteract the rear caliper on the right. I left mine on the right side of my '71 and upgraded the rear to disc with the stock caliper on Kimtab wheels and Yamaha XS 750 rotors. Had to sort out pads that were more compatible with SS rotors.
Short answer is that I noticed nothing untoward with having the brake hardware on the same side of the vehicle.
I believe that Norton just wanted to move it over to the left side and didn't want to spend any tooling money to mount it behind the fork leg.
Too bad, we'd have options for dual disk front ends.