Topic: removing drum brake liner

[SEBNN]

I am converting my rear drum brake to a disc brake setup and was wondering if anyone knows if it is possible to remove the drum brake liner.  I am looking to remove the rotating mass as I will be adding a disc and adapter plate to convert mine to something more modern.  If I cut it carefully will it fall out in pieces, is it held in with a glue, or just a press fit?
Thanks,
SEBNN

[rangelov]

I believe it is cast in place.  It would be impossible to remove.

I might be wrong.  If it is pressed into place, It might fall out if the entire hub is heated in an oven.  Aluminum expands much more than iron.

[bryanj]

The Hub is cast arround the drum and to remove you would have to turn it out in a lathe

[SEBNN]

The Hub is cast arround the drum and to remove you would have to turn it out in a lathe

Good to know before I started cutting and throwing it all out of balance.  thanks!

[754]

The OD of the drum is not smooth it is ribbed to hold it in place.. at one point while turning it will come apart in big chunks.

why bother  riuning the hub, just run a quart less gas...
Better yet just build a nice hub if you have a lathe to use.. it would be fun and not that hard to do... look better too..

[paulages]

The OD of the drum is not smooth it is ribbed to hold it in place.. at one point while turning it will come apart in big chunks.

why bother  riuning the hub, just run a quart less gas...
Better yet just build a nice hub if you have a lathe to use.. it would be fun and not that hard to do... look better too..

quart less gas wouldn't reduce rotating mass. 520 conversion would though.

[SEBNN]

The OD of the drum is not smooth it is ribbed to hold it in place.. at one point while turning it will come apart in big chunks.

why bother  riuning the hub, just run a quart less gas...
Better yet just build a nice hub if you have a lathe to use.. it would be fun and not that hard to do... look better too..

quart less gas wouldn't reduce rotating mass. 520 conversion would though.

520 conversion?  Why would I reduce displacement?  Or is this referring to a wheel?

Also, does the drum or the brake liner turn into big chunks?  Is the brake liner a structural member of the hub or is it just for breaking?  And yes, this would be to counteract the addition of rotating mass that a disc will add.

Thanks for the replies.

[754]

If you are worried about rotating mass and have access to a lathe, build a hub.. be way lighter.

While at it, thin the disc and drill it if you are using the old 750 / 500 anchor.


The liner will come out in chuncks cuz it is a casting and not perfectly round, and not perfectly centered. By removing it you may cause the hub to flex slightly or even crack. But hey, its your wheel.

[SEBNN]

If you are worried about rotating mass and have access to a lathe, build a hub.. be way lighter.

While at it, thin the disc and drill it if you are using the old 750 / 500 anchor.


The liner will come out in chuncks cuz it is a casting and not perfectly round, and not perfectly centered. By removing it you may cause the hub to flex slightly or even crack. But hey, its your wheel.

Two years ago this would have been easy as I had access to a cnc.  I will probably end up just welding the rotor mount on it and loosing 20 lbs of my own weight.  Sure it won't be the same, but I dont have a lathe or a spare to practice on.  oh-well, better slight weight gain and better braking.  I'll be using a rotor and caliper off a sport bike built in this decade.  Just want to go with better components that match my rearsets.

[754]

You are going to weld a piece to the brake side of the hub?

You wouldnt need a CNC for a hub, it is way simpler than most realize, can be done with just a small lathe, rotary table would help (a bit easier) , but not that necessary.

[SEBNN]

That was the original idea, there is about 0.5" of room where a disc would press in and be weldable.  Then I just need to worry about the spacing of the disc off the hub to match the caliper.  I like the hub idea, but I really don't have access to the right tools that I would feel comfortable riding on it.

[eurban]

The OD of the drum is not smooth it is ribbed to hold it in place.. at one point while turning it will come apart in big chunks.

why bother  riuning the hub, just run a quart less gas...
Better yet just build a nice hub if you have a lathe to use.. it would be fun and not that hard to do... look better too..

quart less gas wouldn't reduce rotating mass. 520 conversion would though.

Paulages is referring to a 520 chain conversion which would use a lighter weight chain and sprocket setup.

[SEBNN]

Ok, that makes a bit more sense than does going to a smaller bore and piston.  I will look at it, I am going to have to replace most basic drive train items, so changing sprocket and chain sizes won't hurt.

[rhinoracer]

Like they said, the hub is cast over the drum which has eight or so oval shaped dowels sunken into the aluminum.

You can turn it down and then pop off the remaining dowels. You'll be removing a bit more than a pound of rotating mass. Ask me how I know that  :

[SEBNN]

Like they said, the hub is cast over the drum which has eight or so oval shaped dowels sunken into the aluminum.

You can turn it down and then pop off the remaining dowels. You'll be removing a bit more than a pound of rotating mass. Ask me how I know that  :

Did it work?  Or did you have to scrap it?

[rhinoracer]

I turned down the drum to a bit over half the width so the shoe centerline would still seat flat against the drum. Weight before and after revealed a drop of exactly 0.49 lb.

I havent ridden the bike with the mods, I'll post when I have.