Convert front drum brake to disk

Stephen Hill · Feb 6, 2014

I plan on converting the drum brake on my 1968 to a disk brake. I have collected a stock Norton master cylinder, caliper and caliper side slider.
I know that the sliders for the disk brake are oval, and the sliders for the drum brake are round.

How necessary do you think it is to find an oval (disk) slider pinch bolt side? Is it reasonable to use the round (drum) slider pinch side?
The oval sliders are probably stronger, but is this critical??

Stephen Hill

pierodn · Feb 7, 2014

Hi Stephen,
To use the old drum type slider you have to reduce the width of the base where you insert the axle and/or remove/adjust the dust cover.
In fact the the drum sliders type have only one dust cover, while the later caliper sliders type mount two dust cover, one for each slider.
Ciao.
Piero

laurentdom · Feb 7, 2014

Bonjour Stephen,

I'm just completing the same upgrade on my Slimline Featherbed.

To me, there is no risk that a round pinch-bolt slider creates a physical weakness compared to the oval one. If you are comfortable with the difference in their look (which is quite noticeable from my perspective), the only thing you have to consider is how to have your rim properly centered between the 2 sliders, as Piero explains. You may have to use shims to compensate for the rim offset (compared to the hub) and the difference of width of a round pinch-bolt slider vs an oval one. But shouldn't be too tricky.

Hope it helps.

L.

PS : if you want it, I have an oval pinch bolt slider available, but to be rewelded because cracked in the pinch bolt area (because of over-tightening as often). Let me know.

Adrian1 · Feb 7, 2014

Any chance of some photos please?

pierodn · Feb 7, 2014

laurentdom said:
Bonjour Stephen,

I'm just completing the same upgrade on my Slimline Featherbed.

To me, there is no risk that a round pinch-bolt slider creates a physical weakness compared to the oval one. If you are comfortable with the difference in their look (which is quite noticeable from my perspective), the only thing you have to consider is how to have your rim properly centered between the 2 sliders, as Piero explains. You may have to use shims to compensate for the rim offset (compared to the hub) and the difference of width of a round pinch-bolt slider vs an oval one. But shouldn't be too tricky.

Hope it helps.

L.

PS : if you want it, I have an oval pinch bolt slider available, but to be rewelded because cracked in the pinch bolt area (because of over-tightening as often). Let me know.

+ 1

Johnnymac · Feb 7, 2014

Are you planning on sleeving the stock Norton Master Cylinder? Left as stock, they don't work very well. I tossed mine on day one. I went with the Brembo Master offered by Colorado Norton Works. Bolted right on and now my bike actually stops. Of course you lose the switch gear but I wasn't concerned about that.

Stephen Hill · Feb 7, 2014

I am chuckling cause I knew this thread would probably get into the sleeved/Brembo/drum/disk loop.
Yes, I sleeved the master cylinder, on several of my Commandos, and that works fine for how I ride.
Last time I turned a stainless steel sleeve and a bronze piston so I could ignore the corrosion issue forever.
Thanks to Piero and L for the heads up on the different widths at the axle end.

If anybody has a good spare disk brake pinch side slider, please let me know.
Stephen

Convert front drum brake to disk

Stephen Hill

pierodn

laurentdom

Adrian1

pierodn

Johnnymac

Stephen Hill

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